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Project Journals => Users Projects => Topic started by: dochubert on January 27, 2021, 09:11:38 pm

Title: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 27, 2021, 09:11:38 pm

I think in my other posts I mentioned that my 3 year old SLA batteries were starting to fail.  I had two separate banks. My main bank that runs my house was (16) 200ah SLA 12v batteries set up in 4 sets of 4 in series for a 48v bank.  They still had lots of umph, but because there were 4 in series (for 48v in each of 4 strings in parallel) as they were discharged they didn't discharge evenly.
So my actual usable capacity was seriously diminished.
I ended up selling them to a guy across town who is going to use them in 12v banks.  He should get quite a bit of use out of them that way.  I thought about doing something like that with them but decided I didn't want to mess with them.

I made a good deal on some used BYD LifePo4 24v 220ah packs from Batteryhookup.com.  After some mishaps with shipping companies I then had to repair 4 of them damaged in shipping.  The first pic shows the shattered pallet they arrived on.

[attach=1]
[attach=2]

I ended up arc welding the terminals back in place using a 12v gel battery and a carbon rod.  Kind of a pain but it worked on all but one.  Batteryhookup replaced the damaged packs so by repairing the damaged units I got 4 extra packs, so a net gain.

The next challenge was to get these heavy packs (125lbs per pack) into place for use.  I had to beef up the shelf where the upper 2 stacks of 2 sit.  Then had to build custom ramps and rig a chainfall to get them installed.

[attach=3]
[attach=4]

That took awhile as I have no help and have to figure out how to safely do it all solo.  Got them in.  Didn't kill myself or drop anything so its all good.

[attach=5]

The second bank is 24v so 6 packs in parallel.  I put them on their sides and strapped them together once in place.

[attach=6]

These required a different custom ramp but only had to lift one at a time instead of stacks of two. 

For both banks I used flattened copper thick-walled pipe for bus bars.  I had picked up a coil of used air conditioner copper at a yard sale last summer.  Peel off the insulation, cut to length and flatten with a vise and mallet.  Beats buying copper bar stock or using/buying welding cable.

Next post I'll talk about hookup.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 27, 2021, 09:13:34 pm
All the pics are flipped 90 degrees left.
If it ain't one thing its another!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on January 28, 2021, 01:10:53 am
Hi Doc well done on getting the batteries in place. They can be pretty hard to move about. I have VRLA batteries and each cell weights about 36 kg. I put them in wooden boxes with lids, Luckily I could pick each cell up individually and put them in the box before connecting them.
Seems that the USA needs a new voting system
When George W Bush beat Al Gore it was claimed that the voting machines were rigged.
When Trump won it was claimed that the Russians influenced the election
Now when Biden wins it is claimed to be a fraud too.
Either people love making spurious claims or your system is broken.
Cheers
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: ClockmanFrance on January 28, 2021, 02:44:32 am
LifePo4,   Nice pics,   

I am very interested to see how you get on with these used LifePo4 batteries.

Please keep us informed.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: solarnewbee on January 29, 2021, 09:06:35 am
Hey Doc,

Nice work! I just recently sold some batteries very similar to those. Inter-connected with aluminum buss bars. Battery hookup ended up refunding quite a few folks for lack of kWh advertised. I got more back than I paid so it was a win. You can see mine were in A server cabinet and my son and I had hell loading them up as they were 168lbs. I like your ramp, I didn’t have the room that. I found that 57v was the sweet spot(max charge) before cell voltages got wacky. David Poz on YouTube, if you’ve seen him, paralleled his and it made a big difference.

I know your going to be very happy with the change.

Best of luck!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 29, 2021, 10:14:53 pm
Hi guys,
The second bank running my water heater setup is 6 modules in parallel for 24v.  They stay pretty even so far. 
The main bank, being 48v, is going to be more challenging.  Yes I've watched David Poz' videos on them.  He did a great job and I learned a lot watching him before I started with mine.  I'm not doing things quite the same as he did, but not that different either.  Since there is limited sun in January here, it's been fairly easy so far.  16s bms for balancing on each of the four 48v parallel sets.  Haven't got balancing on the 24v bank yet, but working on it.  To balance those I either have to parallel all the cells across all 6 or put a separate bms on each.  Since I'm only using the bms for balancing, not charging or discharging, I'll probably go with a bms on each.  Still pondering...

Ah, politics.
140 M registered voters.
Trump officially got 74 M.
Biden got 80 M.
That's 154 M total votes "counted" out of 140 M?
Yeah, I'd say it's broken.  Corrupt beyond repair.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 30, 2021, 05:42:28 pm

AsI mentioned, I used flattened thick-wall 3/4" copper pipe for my bus bars.  1 pos and one neg.  Bought large copper lugs from home depot to put on the battery posts, then bolted thru to the bus bar.  Ran new #6 copper wire to each of 4 charge controllers.  Still using xantrex c40 for charging.  Bulk charge set to 55.2v and float at 54v.  As mentioned, charging above 56v leads to unbalances in cells so will try to stay in the narrow range and see how that works out.  No higher than 56 and no lower than 48v.  Usually between 52 and 55v

[attach=1]

Added a temp control and 4 small fans to the charge controllers.  Last summer I just set a desk fan blowing on them.
About time I did something better.

[attach=2]
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 30, 2021, 06:11:42 pm

Next was connecting up the bms'.  Too much trouble using the connectors on the BYD modules so just cut the wires (1 at a time) and connected to the bms wire harness.  One 16s bms to span the 2 byd modules in each 48v leg. x4 so lots of little connections.

[attach=1]

Just used silicon to stick the bms to the module case.

[attach=2]

[attach=3]

Then added a little blue voltmeter to each module.  They are not super accurate but gives me a ballpark idea of whether cells are even at a glance.  Used some plastic wire looms to try to dress up all the leads.

[attach=4]
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on January 30, 2021, 06:48:31 pm
Finally, I added a little blue led to the right of each bms.  Since these bms are relatively cheap, I can't monitor cell voltage directly, and I'm not using them for charging/discharging, only for balance.  The led just connects to the unused bms' charging lead so it will always be on if the bms is in normal mode.  If a cell goes too far out of spec the blue led should go out, indicating the bms has 'disconnected'.  Same if the total module charge gets too high or too low.

[attach=1]

This summer when I will have 120 to 150 amps going in (thru 4 controllers) I'm hoping these will help me make sure the parallel legs are charging evenly.  Also why the charge controllers are set just below 56v instead of the 58-59v the system should be able to accept if it was new.  As for now (January) I'm happy on days where there is enough sun to run the house during the day.  And of course if the grid goes down I can run for a few hours with minimal usage.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: WooferHound on February 02, 2021, 09:02:34 am
Wow , Too Cool . . .
Nice to see someone else converting Lead Acid to Lithium.

Would love to hear about the differences you have seen  between the two systems ?
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on February 02, 2021, 02:52:29 pm

I have to admit that I know almost nothing about lithium batteries as far as practical experience goes.  I'm learning as I go.  Did a lot of reading and watched many videos by other people using lithium.  Opinions and advice seems to vary widely.  Learned all I could then made my own decisions.  Many could prove wrong...

Impressions so far;
I like that voltage stays pretty steady under varying loads.
The fairly narrow voltage range worries me some but so far not an issue.
Cell balancing is something I think I still have a lot to learn about.  Will probably end up changing what I'm doing now.
I love that too low a charge level doesn't do permanent damage.
I like that there's no outgassing.
I like that fire hazard is minimal.
Looking forward to a longer lifetime for lithium. (Only got 3 years out of the SLA batteries)
My Inverter actually seems to run cooler, I think because of the more stable battery voltage level.
My other controls cycle less, same reason.
Hadn't thought about it till now, but output AC voltage is probably more stable and steady for same reason.  Less wear on household electronics and appliances.

I'm just getting started, and summer is months away, so I've no doubt I will have more comments as my experience increases.  Happy so far.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on February 10, 2021, 09:19:41 pm
Hooked up a couple of cell monitors to the Lifepo4 modules of my 24v water heater battery bank.  I bought two different types to check out.
The first one is nice in that it gives a single screen view of all 8 cells at once.  It is supposed to balance cells. 

[attach=4]

Its called an ISDT BG-8s.  Here's a link if anyone is interested in looking it up.  I paid $22.  It's since gone up to $35.

https://www.ebay.com/itm/ISDT-BG-8S-Smart-Battery-Checker/372744580497?hash=item56c94eed91:g:hacAAOSwuA1dWfzY (https://www.ebay.com/itm/ISDT-BG-8S-Smart-Battery-Checker/372744580497?hash=item56c94eed91:g:hacAAOSwuA1dWfzY)

I ran this one for over 24 hrs on my most uneven module.  Didn't see much change so not that impressed with its balancing.  I realize these are big batteries so balancing by small balancers will necessarily take time.  I might need to get more substantial balancers.

The second cell monitor I tried is called a Cellmeter8.  It just has a simpler lcd readout (not all cells displayed at once) but does show minimum cell and maximum cell and a screen that displays the min-max difference.  Kinda cool.

[attach=5]

[attach=6]

These gadgets are cheaper than the other one at about $10-11 each.  Link below;

https://www.ebay.com/itm/Battery-Meter-Checker-Tester-CellMeter-7-8-Capacity-LiPo-LiFe-Li-ion-NiMH-Nicd/133627203511?hash=item1f1ccd4fb7:g:KwYAAOSwtCBf8rug (https://www.ebay.com/itm/Battery-Meter-Checker-Tester-CellMeter-7-8-Capacity-LiPo-LiFe-Li-ion-NiMH-Nicd/133627203511?hash=item1f1ccd4fb7:g:KwYAAOSwtCBf8rug)

Left it on all day today and balance has noticeably improved in just that time.  Guess which one I'll get more of?
I like the display on the ISDT unit better but like the balancing on the Cellmeter8 better.  I want each module on the 24v bank to have a balancer, so ordered a few more Cellmeter8's.

The 48v bank is set up for 16s bms so can't use these for that bank (without re-doing all that wiring I spent hours hooking up).  Nobody seems to make anything like a "cellmeter16".  I know some of the very expensive bms' have bluetooth so you can read it on your cellphone.  Times 4 for 4 banks.  At this point not willing to spend that much.

I also have an 8s Daly like the 16s units on the 48v bank.  So I'll hook the 8s up to one of the 24v modules and see how it does versus the cellmeter.  Time will tell.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: WooferHound on February 12, 2021, 07:19:51 am
I use this Active Balancer on my bank with great results

https://www.ebay.com/itm/2S-8S-10S-17S-Li-ion-LiPo-Lifepo4-LFP-Battery-Active-Equalizer-BMS-1-2A-Balancer/312774496524?hash=item48d2d0110c:g:8aAAAOSwHuldgg2P


This Active Balancer is recommended highly on YouTube

https://www.ebay.com/itm/5A-Battery-Cells-Balancer-Universal-For-LTO-LFP-Li-ion-Battery-Active-Equalizer/313099411423?hash=item48e62ddfdf:g:rwgAAOSwAu5fmXvH
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on February 18, 2021, 03:51:15 pm
Thanks for the info and links, Wooferhound.  Since my last post the cellmeter8 balancer hasn't been able to keep up and balancing is still not great.  Not terribly bad but not great. 
So ordered a couple of the ones in your first link and will give them a try.  I can't really go to a 5a balancer without going to bigger wire size, and that's next to impossible for now.  (Moving those big lifepo4 modules again is something I don't want to think about.)
So I should be ok with a 1.2a balancer with current wire size.  Assuming 1.2a is enough to do the work.  Guess we'll see...
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on March 16, 2021, 06:14:15 pm
Got the 2 1.2a active balancers recommended by Wooferhound and hooked them to the two worst modules.  Of course they haven't instantly put them in balance, but they seem to be working fairly well (a week or so of use so far).  The used Byd modules tend to go out of balance when at the top end of charge.  In my case, above 27v.  Battery hookup recommends using them in the 24-27v range, probably for that reason.

[attach=1]

So they get out of balance somewhat near the top end, the balancers work and they're within acceptable balance eventually.  Since its early spring, I have longer Sun days ahead.  We'll see how they do when the batteries stay at fully charged for longer each day.
Anyway, I ordered 4 more so there will be one for each of the 6 modules in the water heater 24v bank.  The 48v bank is more challenging.  I already wired up the 8 modules in 4 48v sets, with a 16s bms for each.  Probably will just put a 16s active balancer on each set in addition to the bms.
I am considering buying 8 more of the byd modules to double the size of the bank.  If I do, I will probably do them differently than the existing set.  Before mounting them, I think I will add wires to allow paralleling all the cells of all 4 48v sets, then use one of the 5a active balancers for the whole thing.  Suspect I'll get better results.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on March 17, 2021, 06:34:55 pm

I did get one 16s active balancer so unplugged the bms on one 48v set and plugged in the balancer in its place temporarily.  I'll give it a few days and see what results I get with it. 

[attach=1]
[attach=2]

Same plug on bms and balancer, but of course they are wired backwards from each other so had to slice off the alignment tabs on the plug to get it to go on the balancer 'backwards' for correct hookup and operation.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on March 20, 2021, 08:32:08 pm

It's been 3 days since I added the 16s active balancer.  Hard to tell if things are improving.  Lights come on indicating it is balancing. Lights are out most of the time.  Since the 48v sets don't go much above 54v, they may or may not be doing me any good.  More time needed.

On another note, I put in my order for 8 more of the byd 24v modules.  This time from Battery Clearing house.  These will add to my 48v bank, doubling the size.  Its probably big enough already so this addition should be overkill.  I'm aiming to have enough capacity to handle the short days/long nights of Idaho winters better.

My original modules are the plain type.  The ones on the way are the type with heatsinks and fans attached.  My plain modules don't even get warm (so far) so heatsinks and fans seem superfluous.  Wondering if I can remove them to simplify things and save weight and space?  Besides, I already have a use for the heatsinks....

Anyway, planning to add larger gauge wire for balancing and paralleling the additional 8 modules, ending up with one 16s4p setup that will have one 5a balancer and will then be paralleled to the existing bank.  If the balancing works better that way will probably eventually reconfigure the original 8 the same way (the current setup is 4 sets of 16s1p paralled together, each of the 4 sets balanced separately). 

Then there is the question of the method for balancing.  In discussion with Sid on the Genetry forum, I'm coming to realize the limitations and possibly design flaws of active balancers.  He makes a convincing argument of the possibility of damage caused by some types.  He has designed a shunt balancer system that bleeds off excess cell voltage as heat.  Wasting power but safer for the system.  So if he makes it available soon might try one.

Keeping these modules balanced as much as possible seems to be the key to them lasting a long time.  I knew nothing about lithium when I started, have learned a great deal in a short time, and still know very little.  Working on it, though....
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 06, 2021, 03:08:02 pm
It's been a few days since I attached the 16s 1.2a active balancer on one leg of my 48v bank.  It seems to be an improvement over the bms, but only a slight improvement.  Planning to go ahead with paralleling all the cells and then attaching a 16s 5a active balancer.  The installed original balance wires should handle it ok, especially since the bank doesn't go above 54.4v.  Might gradually increase voltage after some settling-in time.  We'll see.

Also got and installed the 4 remaining 8s 1.2a balancers on my 24v bank byd modules.  Each module now has one balancer, plus one of the cellmeter8 gadgets so I can tell what's going on.  It's been a few days and they seem to be doing ok.  Above 27v they still go somewhat out of balance but probably good enough for my needs.  Still could parallel all of the cells on these but not right away.

My shipment of 8 additional byd modules is scheduled to arrive today.  Waiting (mostly) patiently.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 06, 2021, 08:33:37 pm
Here's a pic of my 24v bank with active balancer and cellmeter on each module;

[attach=1]

The next two are front and back of the 5a balancer to be installed on the 48v bank;

[attach=2]
[attach=3]

Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 08, 2021, 08:36:56 pm

The 8 additional byd 24v modules finally arrived.  I have already started removing the heatsinks on one.

[attach=1]
[attach=2]

These heatsinks are massive!  They are 1.5 inches thick, 21 inches long and 12 wide.  They must weigh 10-20 pounds each. 

[attach=3]
[attach=4]

Then there is a high speed 24v fan on each module.  They must have really used these modules under heavy loads to need such massive cooling power.  My existing set of modules has not even gotten warm to the touch, and they are the version with no heatsinks/fans.  Hence my removing the heatsinks on these.  I don't expect these to get warm either, especially since I'm adding them to the existing set which already stays cool.

Besides the reduction in weight, removing the heatsinks reduces the overall size of each module to approximately the same size as the original set.  I have limited space where these are going.  My first set of modules just barely fits so I had to make the new ones fit also.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on April 09, 2021, 02:26:36 am
Hope they work out for you Doc.
It seems that using lithium batteries is a very complicated process. I hope that they last a long time.
You are on your way to becoming an in house expert on these things
Good luck
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 12, 2021, 09:24:23 pm

Thanks Pete,
I'm learning as I go, definitely not an expert. 
I've been busy with other chores, but have gotten two of the eight stripped down.  (Heatsinks, fans and covers removed)  Also have added wires attached to each cell to be used for paralleling all the cells. Also eliminated the inconvenient round posts for positive and negative connections.  These modules are a bit different from the other modules I'm already using.  With these I can remove the round posts and just use the double bolts where the posts were mounted. Much handier. Saves me cash too as I don't need to buy the large copper lugs to adapt the round posts.  A definite plus!   Also, removed an internal busbar that I'm hoping to use for paralleling the modules.  I think they are tinned copper so should work well.  These modules must originally have been much more expensive than the other simpler type I bought the first time, considering all the extra parts.  Same cells, just more 'optional equipment'.  I suppose the 'simple' version would have been intended for a temperature controlled environment.

So, two are ready to move downstairs.  Six to go.  I'm doing this stuff in my garage.  My poor pickup is sitting outside until I'm done with the modules.

On another note, the heatsinks are interesting.  They seem to be two pieces pop-riveted together.  A normal heatsink you would expect to see one flat side and one side with fins.  These have a second flat plate over the finned side.  The air has to move through this 'tunnel'.  It would be difficult for me to use them like this.  So, I drilled out the rivets on one but haven't been able to separate the two parts so far.

I'll get some more pics up soon.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 13, 2021, 08:36:49 pm

Finally got one of the heatsinks separated.  Turns out the two pieces were glued together as well as pop riveted.  I left a heatsink bolted to a module to give me leverage to pry it apart.  It was still a bear.  Bent a fin or two.  Nothing serious.  Not sure how I'm going to get the glue off as it feels like hard plastic.  Maybe I'll heat it with a torch to soften it.  Anyway, the part with the fins looks all gray in the pics due to the glue/plastic.

[attach=1]
[attach=2]
[attach=3]

Three of the modules are now ready to move and be installed.  Pics show wires sticking out.  I'm adding these to let me parallel all the cells between modules after they are mounted and just before they are hooked up to solar.  Also you can see that I have removed the round posts and will be using the double bolts on the top corners.  This top view will be the front when they are laid down in their resting positions.  Two stacks of four modules side by side.

[attach=4]
[attach=5]

The negative round post was connected to the actual negative terminal by these two busbars.

[attach=6]

The skinny looking busbar is what I plan to use for paralleling the four modules in each stack.  Hate to waste stuff. 
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 14, 2021, 10:22:19 pm
Was looking a bit closer at that busbar.  Looks black in the pics.  It appears to be triple wrapped with electric tape!  It was mounted where it could make a spectacular short to the cell connections, so I can see why the tape.  Someone spent quite awhile just taping!
I'm still amazed how much work/money and how many extra parts went into making these modules temperature regulated with the fan/heatsink setup.  These must have cost twice as much as the simpler versions originally.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 25, 2021, 06:15:09 pm

Still working on the byd packs.  Adding wires for paralleling and removing extra parts like fan and heatsinks.  Two to go.
Then I have to mount a terminal strip on the front face of each pack and connect up the wires.

I finally got the glue/plastic/whatever it was burned off of the finned half of the one heatsink I separated.  Gave up on the small torch.  Took nearly 30 minutes to melt off just half of it.  Got out my weed burning rig and finished the rest in a few minutes.

My shunt balancers were finally available from Genetry so got them ordered.  Genetry is famous for its terrible shipping record so no telling how long till they get here.  The heatsink is now ready.  Just need to finish the prep work on the byd packs/modules and get them moved to position.  Then the fun part!  I have to rig the chainfall to lift them into final resting/mounting place.  Will need to build a custom ramp also like for the first set.

When that's all done I can start connecting them up to solar, and finally in parallel to the other set.  Somewhere in there I will be connecting up the shunt balancer setup to the whole set.  Lots of fun ahead!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 27, 2021, 07:03:36 pm

All eight of the byd modules are now stripped down and wires for balancing/paralleling added.  Yay!
Now I'm figuring out how I want to mount the terminal strips on each module.  I was going to do that after I got them rigged into place, but realized I won't be able to easily remove and replace the pop-on covers once the modules are in place.  So have to do it now.  It means the modules will be more delicate while I'm moving/rigging them into position.  Oh well.
I had 3 or 4 different ideas on how and where to mount that terminal strip.  Looks like it will be right on the 'front' of the module mounted to one of the pop on panels.  One terminal strip on each module.  Then I will interconnect the modules when they are in place downstairs.  I'll post some pics once I get some done.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on April 29, 2021, 08:24:25 pm

Made some progress in between irrigation work today.  Terminal strip mounted on all 8 modules.  4 of those wired up and ready to move downstairs.
[attach=1]
[attach=2]


 
Title: Re: Changing from SLA to LifePo4 batteries
Post by: lighthunter on May 01, 2021, 12:17:08 pm
Hi Doc! looks like fun project is going well.
How do you like the performance of em compared to lead acid?

If lead acid is big enough and healthy enough they do work well also but lead acid is less forgiving on an undersize bank.

How did you do on price? Of course price is subjective anyway with brand cross comparison.   The last ones i bought were $1280 for 160AH at 51.2v or 15.6¢/wh the first ones i bought were 48.8¢/wh,  i see you can get littokala new for about 20¢/wh
Both that i got tested true to advertised rating but cycle life was 4000 on the more expensive ones only 2000 on the cheapee.
ones. I just like to keep an eye open because the cheap deals arent always cheap but there are better deals.

LH
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 02, 2021, 10:27:34 am

Hi LH!

Quote
How do you like the performance of em compared to lead acid?
They are so much better it's hard to compare.  Much less fluctuation of voltage, which is easier on the inverter, and helps keep the inverter's output steadier too.  With less up and down, the inverter seems to run cooler too.  The more narrow voltage operating range worried me at first, but as just stated turns into an advantage overall.
If someone offered me brand new top-of-the-line 200ah SLA/AGM batteries and offered to do the work to change them out, I would decline instantly.

Quote
How did you do on price?
My first set of 10 BYD modules were $275 each plus flat $350 shipping from Battery hookup.  Second set of 8 were $295 each with $300 flat shpping from Battery clearing house.
It's hard to judge the price per wh with used modules, but I think it was a very good deal overall.  You can't currently get that price for the BYD any longer except for a local pickup price (and North Carolina is too far for me)
As long as these hold up I have plenty for my needs so I'm good.

I would be interested to know how much these BYD modules cost back when they were new.  Must have been a fortune!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 12, 2021, 04:19:16 pm
Made first attempt at lifting battery modules in place.  Unsucessful.

[attach=1]
[attach=2]

The wood 'ramp' was too flimsy and not anchored well enough.

[attach=3]
[attach=4]

Got the set lifted but couldn't make the shift over to the shelf.  Set it back down.

Plan B.
Reconfigured the lift cart to give me a few more inches of lift height.  Eliminating the wood ramp.  Moving the chainfall anchor point in closer to the shelf.  Will be trying to lift again shortly.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on May 12, 2021, 07:41:44 pm
Good luck Doc. Looks like a heavy battery bank. Pity there isn't a way to fit a pipe on the rafters so the chain block can't be slid along it. Hope it is a very long time before they need to be taken down
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 12, 2021, 08:45:07 pm
Thanks Pete,
Yeah, a set of two would be over 250lbs.  Good thing I removed two 20lb heatsinks from each module.  With the heatsinks they are said to weigh 168lbs per module.  Had to remove them for space considerations as well as weight.  It's a pretty tight fit as is.  Once they are in, I'm hoping it's the next owner of this house who will face taking them out!  ;)

Well, I got the first set of two onto the shelf.  Done for today.  I'm exhausted.

[attach=1]

Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 14, 2021, 09:43:21 pm

Finally got a chance to get the second set up onto the shelf.  Hauled 4 loads of firewood yesterday and a trip into Nampa today, but got them in!  Sadly, the first four were the easy ones.  Now I get to figure out how to get the next four on top of these four!  I do have a plan in mind but will it work?  The remaining four must be lifted into place one at a time, as I haven't got clearance to lift stacks of two that high.

[attach=1]

So, I next need to modify the lift cart, cut some wood spacers, and then we'll find out.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 19, 2021, 10:01:49 pm
3rd set of two up.
[attach=1]

I know.  Looking at the picture, you're thinking, "What's the big deal?"
I spent several hours trying to get those two up there. I'm at the limit of my lifting range.  Had to modify the lift cart to get those up high enough.  Was off by an eighth of an inch.  They are too delicate to force-fit.  So more modifying. By the time I finally got everything to line up I had had the thing in the air 4 times and had to lower it back down and re-adjust.

Well, they are in.  Problem is, there are two more to go on top of those.  And the chainfall can't lift them high enough.  I do have a plan.  Tomorrow we'll see if it works.  Tonight I'm exhausted (and the chainfall did most of the work!).
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 20, 2021, 03:37:22 pm
Progress!
Lever top one from right hand stack up onto left hand stack.  Pain in the butt and took awhile but got it.

[attach=1]
[attach=2]
[attach=3]
[attach=4]

Then lift another onto right hand stack;

[attach=5]

The last one is the b**ch!  Can't lift it high enough.
Going to have to build a ramp or platform as an intermediate step, then muscle it in.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on May 21, 2021, 12:01:23 am
HI Doc it may be a bit late but if you use a piece of plywood as a ramp , and use pieces of dowling or old broom handles for rollers the battery packs will be easier to move into place.
I have used old wooden tent poles for rollers to get slow combustion stoves off a trailer up a ramp onto a house verandah and move them inside. Made the job pretty easy for me.
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 23, 2021, 09:03:50 pm

Hi Pete,
Thanks for the ideas.  Space is my limitation.  It's a real small area.  The other set of 8 let me use a ramp for the upper sets because it was a straight shot and I had my son-in-law to help me push them up the ramp.  This time it's just me and this set is in the corner.  Not a straight shot and stuff in the way so ramp won't work.
So, for this last module, I built an intermediate platform.

[attach=1]

Tomorrow I'll lift the module onto the platform with the chainfall.  Then lift one side and slide a 2x4 under, lift other side and slide another 2x4.  Keep doing that until the battery module is high enough to slide onto the stack.  Should work out ok.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 26, 2021, 04:39:27 pm

I was uncertain a time or two, but it's in!  Hydraulic jacks are wonderful!
Put a crosspiece in, then used the jack to lift one side.  Put a 2x4 in.
Do the same on the other side.  Repeat until high enough, then push it onto the stack.
A little shaky towards the top but it's all good.  Relieved the heavy lifting is done.

[attach=1]
[attach=2]

Now it's hookup time!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 26, 2021, 09:51:49 pm
Each one of the byd modules had these two busbars, which I removed while removing the heatsinks, fans and such. So I have 8 of each type.

[attach=1]

One is a flat wide bar of what appears to be stainless steel.  I flattened out the bends to make one long flat piece and will use it to be the interconnect between the two 24v halves of the 48v bank.  With all cells paralleled, this one bar will make all the interconnects.  Might double up (use one on top of another)
The other one is 1/8" thick copper wrapped in black electrical tape.  Removed the tape and buffed off the copper.  Will use one as the positive and another as the negative busbar.  Might double them for 1/4" thick busbars.

[attach=2]
[attach=3]

Tomorrow will drill the holes and bolt things up.  Then it's on to paralleling the cells.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on May 27, 2021, 01:35:04 am
well done Doc, I hope for you that the batteries outlast you. May you never have to replace any of them.
What capacity do you have there in batteries now?
cheers
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 27, 2021, 01:41:00 pm

Thanks Pete,
The 48v bank is now 16 BYD modules (24v each).  They had a rating of 220ah when new.  That would make the bank rating 48v@1760ah if it was new.  So something less than that.  Maybe half?  880ah?
Should be more than adequate at any rate.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 29, 2021, 08:42:56 pm
Got two of the three busbars made up and installed.  Used the wide flat bar for the interconnect between modules.  Turns out it is copper with a chrome plating.  Straightened out the bends, drilled a bunch of holes, stacked three to make it thick.
Used two stacked of the skinny copper bars, with the electrical tape removed and polished up some for the positive busbar.  Cut off the round post but left the side tabs at each end for extra connection points.
Now just have to do that again for the negative busbar.  Tomorrow hopefully.

[attach=1]
[attach=2]
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on May 31, 2021, 05:23:43 pm

Yesterday I made up and installed the negative busbar.  Today I've gotten most of the cells paralleled.  Had to quit for awhile. Doing wiring like that makes my back hurt and my eyes cross after awhile.  I'll finish up a bit later.  When I'm done the eight modules effectively become one huge 48v battery instead of 4 paralleled 48v batteries.

[attach=1]

Next will be mounting and wiring the shunt and active balancers.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on June 03, 2021, 03:19:38 pm

Got the 5a active balancer mounted and wired in last night.  The new set of modules is now connected to one of my 4 charge controllers and is charging up today.  When it's up to same voltage as the existing set, I'll make the parallel connection to put it in service.

[attach=1]

Still working on the shunt balancer setup.  More work and a little more complicated.  When it's all done the active balancer should handle things up to a point.  When a cell's voltage goes above the setpoint, the shunt blancer will kick in and bleed off excess the active balancer can't handle.  Due to the way it works the shunt balancer requires a sizable heatsink/fan setup to get rid of the heat from bleeding off excess power.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: lighthunter on June 13, 2021, 06:13:49 pm
Looking good! You have quite an achievement there. Very massive storage. I dont reckon you will ever need more than you have now. Nice thing about LFP is the self discharge wont kill you like it does with very large mostly spent FLA.

You likely have your own preferences but i like to bottom balance cells so they all drop voltage at the same time when empty and terminate discharge when you hit 47.2 or 2.95vpc.  Then terminate the filling charge when the smallest capacity cell climbs over 3.5v.  active balancers depending on programming often shift charge levels at top and bottom throughout every cycle to eek the highest capacity. Its a cool idea in theory but it has limited value when considering wear and tear on cells and balancer.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on June 13, 2021, 10:51:23 pm

Thanks LH,
The 5a active balancer is doing a surprisingly good job keeping the 'new' half of the bank's cells even.  The smaller 1.2a active balancer on the 'old' half of the bank struggles to keep things even. 
I'm almost ready to add the 5a shunt balancer setup to the 'new' half, after which I will remove the individual small bms' and 1.2a active balancer from the 'old' half, parallel all those cells, then connect the 'old' half's cells to the 'new' half's cells, completing the paralleling of the whole bank. (whew!)  It will truly be one large battery at that point.  The combination of the 5a active balancer plus the 5a shunt balancer should be able to handle whatever happens....

I've been running a narrow charging range; only up to 54v(3.375v/cell) until all the above was done.  Once done and settled in, I'll start bumping the top voltage up some. Hoping to get to 56v (3.5v) while still maintaining cell balance.  I'll be happy with 56v.  I do fine with 54v, just think I can squeeze a little more capacity out of this big bank.

As far as low voltage goes, I have no plans to run below 48v.  Mainly because powerjack inverters start losing the nice sinewave below 48v.  Also the lfp batteries drop voltage quickly below 48v.  So I put an alarm on the bank that sounds when it dips below 48v.  It's only going to happen in winter (or other unsual circumstances - like several consecutive stormy days).  Then I have to switch over to (ugh!) grid power.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 05, 2021, 12:28:08 pm

Haven't had much to post about for awhile.  Long summer honey-do list plus 100F+ temps since early June have limited my productivity. (It's not that great anyway!)  I have managed to get the cells paralleled on the 'old' half of the bank.  Removed the 4 daly bms' and the small active balancer from that side.  The bank is now balanced better from just being paralleled than it was with all the small balancers in use.  Guess I'm continuing to learn.
Also did the wiring for the 5a shunt balancer setup.  It's ready to mount.
[attach=1]
Once it's up in place I can start hooking it into the 'new' half.  I'll let that half settle in a few days before paralleling in the 'old' half.

Other than that stuff, the 15kw powerjack is humming along, doing an excellent job of running the house 24/7.  Sadly, those 100 degree+ daily temps have forced me to run the central air, which means paying Idaho Power to run it on grid power.  I never planned my system to run the ac because we typically only need it 14-15 days per year.  It'll be closer to 4 solid months worth this summer.  I'll pay it, because we're not willing to be miserable to avoid paying.  Not worth it and not the point.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: lighthunter on August 05, 2021, 02:17:06 pm
Hi Doc! I removed our central AC about a year after buying the place when i realized it needed recharging. I didnt want the annual service bill that comes with many of those. So we run two 8Kbtu window ACs 24/7, they both cycle a fair amount, keeping everything between 70-74F. Love the setup and easy to manage with solar powerwise We have a large home but is insulated well. I leave 3 oscillating fans on 24/7 one in garage and one each near the AC units. Weve been using around 25kw daily from the solar and since i dont have that much storage the solar switches to grid 8-9pm every evening and switches back at similar morning hour. So 12 hrs on grid as hot its been used about. 700kwh from grid in july so guessin you still got me beat HA. Without the heat load the solar normally lasts till 2 or 3 in the morning dropping the grid use to 350kwh (electric range, dryer and DHW) Theres room for better utilization here since the 6kw of panels could do 50kwh most days. But hey its miles ahead of doing no RE at all. One of my future ambitions is to drive to work on RE. With the butheads running our gov gas will probably be pretty expensive.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on August 05, 2021, 05:47:05 pm
Wow LH, you keep the house hot. 70 to 74 F wow. Where we live if the house gets to 21C (69.8F) we open the door to let the house cool down a bit.
Seems odd to me that we see people in Summer who want their houses to be freezing cold then in winter they want their houses to be hot.
I reckon that our blood has thickened a lot and consider it to have the viscosity of molasses now. We don't have AC because we only get a couple of days a year that go above 25C (77F) which we consider hot. On those days we keep to the shade.
Cheers
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: rossw on August 05, 2021, 09:07:12 pm
we only get a couple of days a year that go above 25C (77F) which we consider hot. On those days we keep to the shade.

Wow Pete, that's barely above frozen!
Summer here we regularly see 45C and on odd occasions 2 or 3 more than that.
Fortunately, to us "cold" is anything below zero, we get a couple of days a year around -3C, and every few years we hit -6 or -7C

Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on August 05, 2021, 10:03:28 pm
Hi Ross, you have much more extremes than we do. On the mountain we live on we have winter days with between 1 and 8 degrees, summer usually 12 to 25 degrees C.
On very rare occasions we get heatwaves of 28 here. In Launceston it gets hotter, but we are usually 5 degrees less than those lowlanders.
Nights well not much below -3 , outside.
Cheers
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 08, 2021, 09:46:27 am

Hi guys!
LH, I do have a window unit ac that I haven't put in a window yet.  I should get around to that....
I'm glad I'm not the only one getting hot temps Ross. Misery loves company.   Jealous of your weather, Pete.  It' supposed to be cooler here this week.  Only up in the 80s(cold snap!-hah!)

Getting the shunt balancer connected up.  Got a new phone, so new camera.  Not my idea.  Sprint says, "Your iphone 5 won't work after January, but boy we have a deal for you!  Free phone!" I took it but still waiting for the other shoe to drop. (One would think I'm not a trusting person!)
Anyway, pics are higher res so take longer to upload.  Still being rotated to the left 90 degrees when I upload so must be my computer doing it.  Before uploading, if I view a pic, rotate it 90 then rotate it back, then resave it, it uploads fine.  No idea.
Still figuring out the new camera, so here's a pic of partially connected shunt balancer.
[attach=1]
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on August 08, 2021, 05:34:24 pm
Looks nice Doc, How many villages are you going to be powering?
Maybe it is time for us all to look at moving underground. Seems that there are giant fires in the US, and Greece.
A few feet of dirt all over the house would be good insurance.
I hope your batteries last for a long time Doc, sure seems like a lot of work you have put in there.
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 08, 2021, 06:04:03 pm
Thanks Pete,
I could definitely power more than I am now.  It's wintertime's short days and long nights I'm trying to provide for.  But yeah, a lot of work.  Hope it will be worth it in the long run.  Hoping these batts last a long time too.
Fires are a worry.  One reason I'm not in california any longer.  Lost my house to the big 03 fire there.  Fires in Oregon and Idaho are a long ways from here, luckily.  Not too many trees here in the immediate neighborhood.  Grass fires I'll just have to deal with if they come.  Hope not.

The shunt balancer is wired up to the 'new' half of the bank.  Pic is pretty good.  You can zoom in and read the cell volts of each cell.  Old camera wouldn't have been clear enough. 
I'll have to wait a few days to wire up the 'old' half.  Not enough wire.  Had to order some more.  Using 14ga stranded hi temp wire. 
Balancer won't do much until both halves are connected and I bump up the charging from 54v to 56v.  Kicks in at (i think) 3.55v/cell.  Each balancer cell is individual.
Wish I had put this one in first thing.  Spent a lot on small balancers, BMS', and active balancers that couldn't handle these batteries.  Learning as you go gets expensive.  I think this setup will do the job properly.  Time will tell....

[attach=1]

Should have waited to take the pic until I had dressed up the wires, but oh well.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 19, 2021, 03:22:54 pm

Ok, everything is connected, all cells are paralleled on both halves of the bank.

Been watching for a couple of days and gradually increasing charge settings.  Float is now 56v and bulk is at 56.8v. Balance isn't bad.  Charging has been hampered some by sporadic sun and smoke from west coast fires.  After a windy night blew some of the smoke out, getting a good charge today at 95a.  Had to fix a couple small things, but now the balancer seems to be doing it's job.  The fan/temp control is doing it's job keeping the heatsink cool.  Still have 3 cells not quite coming up to the rest at this setting, but improving daily.  Will give it a couple more days at this setting and see what I get. 
Title: Re: Changing from SLA to LifePo4 batteries
Post by: lighthunter on August 20, 2021, 09:25:59 am
Hi Doc!  Lookin real good. You do nice work!
It is enjoyable when it all works like it should.   New LFP prices are about 1/2 what i paid a few years ago.  $500/kwh 2016 vs $500/kwh today. Now its a thinker between FLA and LFP on price. FLA still beats LFP on up front cost but the value brings LFP ahead. Do you have any statistics on your used cells DOC? Are they 5yrs? 10Yrs old? Roughly how many cycles and i think you said the capacity now is like 70%? That info may help others make decisions but i realize it may not be available. I plan to do a capacity check on my 5yr old cells to see how they are holding up and will report that soon.

Iphone i know nothing about but do know my phone camera has a setting if i want picture saved by orientation sensor or left original.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 20, 2021, 04:49:35 pm
Hi LH,
I don't know how old the BYD modules are.  There was no info available.  No labels with any dates.  (might be in chinese!)
I just had to take a chance based on the cheap price.  Hoping they will last long enough that prices to replace them will be much more realistic.  As you point out, the prices are already dropping.
To my knowledge, There are no more BYD modules available anywhere.  Right after I bought my second set they all disappeared (at least online).

Also figuring the large size of my battery bank will help extend the lifetime by reducing severe cycling.  Guess time will tell.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: lighthunter on August 21, 2021, 12:32:12 pm
Hey Doc! Thanks 4 the feedback. You did really well with your storage setup. Very few have capacity like you do now.
I was looking at the cell monitors you have, (cellmeter) do those have an output contact or audible alarm for low/hi cell volts?  The cellog8S has this but they no longer make it. Too bad seems wierd they discontinue popular products like that.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 21, 2021, 10:52:31 pm
Hi LH,
As near as I can tell, the cellmeter8 has no alarms at all.  It supposedly has a way to test a servo, if you could make that usefull. 

The translated instructions are terrible, so not really sure if it is trying to balance or not.  It wouldn't have much effect on my batteries anyway.
I bought them as cheap real time voltmeters and (approximate) state of charge readouts.

Also have a ISDT BG8s meter.  Costs 3x more than cellmeter8. Cooler display.  Shows all cells on one screen.  Actually seems to do some balancing.  No alarms that I can see.
Sorry, not much use to you seems like.

Funny how test equipment changes over time.  Many years ago I used to use a Simpson 260P multimeter working on navy ships.  Was considered the best you could get.  It cost way more than I could afford then.  Bought one in great shape last weekend at an estate sale for $8.  With case.  This weekend got an Amprobe clamp-on ammeter for $6. Also with case.  Couldn't afford one of them back then either.  Digital meters have displaced them, so guess I bought them out of nostalgia.
The meters we're using today won't last long enough for someone to find (still working!) at an estate sale years from now.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 22, 2021, 10:28:47 am
Have to correct my earlier statement.
The ISDT8s does have a settable, audible  low cell voltage alarm.  No high voltage though.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 22, 2021, 09:16:27 pm

Balance continues to improve slightly daily.
The 3 cells that are a bit low are gradually coming up. (getting closer to the rest)
So will leave the settings where they are and watch for a few more days.

I do like these batteries!
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on August 23, 2021, 05:11:52 pm
Good to hear that it is working out for you Doc.
I hope that all the work setting them up is worth it and they last a long time.
So far I am loving my new setup too, the sealed lead batteries I have are enjoying having the capacitor bank to make starting things easier. The 500 farad capacitor bank are doing a great job and my compressor just fires up straight away with no hesitation.
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on August 25, 2021, 09:40:01 pm
Thanks Pete,
Glad your capacitor bank is working out for you.  Sounds interesting.  Did you describe it in another post? (I haven't been paying attention lately, sorry)

The shunt balancer seems to be a success!  I will be leaving the settings on the charge controllers where they are (56.8v bulk, 56v float) unless I see some reason to change them.  Balance is very good.  Probably as good as I can expect from used batteries.
Now I just have to put the same type balancers on my 24v bank.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on September 14, 2021, 04:54:45 pm
Got some work done on the 24v bank balancer setup.  Bought 4 of these heatsinks and cut them in half.

[attach=1][attach=4]

Cut some wood pieces and attached as shown.

[attach=2][attach=5]

The balancers/heatsinks will be electrically isolated from one another, which means the balancers can be mounted to heatsinks without insulator pads (better heat transfer).  These heatsinks are not very big, but my experience with the huge heatsink on the first set (48v setup) tells me it was overkill.  Hopefully these small individual sinks won't be 'underkill' and will do the job.
On the backside, two 12v standard 4" fans temperature controlled.

[attach=3][attach=6]

Still awaiting delivery of the balancers, and haven't completed paralleling all the module cells, but some progress anyway.
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on September 15, 2021, 03:41:37 am
Hi Doc looks like you have a plan going there.
I don't know enough about lithium batteries but it sure seems that they want a lot of stuff to control them.
I read somewhere that a University in Queensland (oz) is working on another lithium battery chemistry. They had one sort working but it was not so good on the number of charges cycles it could do, then they worked out that adding sugar to the cells coated the cathodes and allowed their charge cycles to be 100 times more.
I guess that in the not too distant future we will see massive improvements in battery technology.
I would love to have an electric vehicle but at the moment the costs are too high. One day maybe they will be cheap enough and we will be able to charge them on our solar system. ( we don't drive much, it is too lovely where we live to want to go out too often).
If the fans don't work you could always put the fins of the heatsinks in a tank of water to cool them.
cheers
Pete
Title: Re: Changing from SLA to LifePo4 batteries
Post by: Pete on September 15, 2021, 03:46:29 am
Here is a link to a short article on the Lithium Sulphide batteries
Pete
[https://www.abc.net.au/news/science/2021-09-14/batteries-lithium-sulfur-sugar-future-electric-vehicles/100457492]
Title: Re: Changing from SLA to LifePo4 batteries
Post by: dochubert on September 15, 2021, 10:29:38 am

Hi Pete,
Thanks for the link.  Looks promising!  I think you are right that there will be large improvements in batteries in the next few years.  Probably making the current versions as desirable as Ni-Cad batteries when lithium first hit the market.

A lot more needed to control lithium batteries versus lead-acid, true.  I think I finally have a setup that keeps my very large bank balanced.  The 48v bank is doing great and staying very well balanced with no intervention from me.  Hopefully my scaled-down version for the 24v bank will work as well. And it keeps the footprint of the whole thing smaller.  I can always go to larger heatsinks or higher speed fans if necessary, but I think these will work ok.   We'll soon know.