guess who bought a power jack inverter

[davidwillis]

Thanks...

That is interesting.  I am currently using a lithium battery bank, which is sitting at 22.8V.   So maybe that is the problem, however my AC voltage is sitting at 234.  This seems like a good voltage, since the grid tie inverter is rated for 211-264VAC.  But I wonder if there is something else that is effected by lower voltage?  Right now I have the range of my battery bank go from 20-25.5 VDC.  I wonder if I should add another battery and put it up to 23.5 to 29VDC?  That would not be too hard to do, and I could easily test it by charging up the bank to 25VDC and see if it syncs,  That could be why it was working better when the grid tie inverter was putting out 6kw forcing the battery voltage up to 24VDC.
Also apparently there are more settings on the inverter that have different parameters, such as for HECO Grid (Hawaiian electric).  I may try some of those and see if they just happen to work...
Keep the ideas coming...  Something will work I am sure of it...
I will update you with what I find.

Thanks!!!!

oztules,

Thanks,   Are you talking about internal hv fuse in the powerjack inverter or the grid tie inverter?

The grid tie inverter is working perfect when connected to the grid, but not when connected to the powerjack.  Also the powerjack works just fine by itself (at least as far as I can tell).  It just does not seem like they play together very well.

@ davidwillis.
What you are dealing with can be frustrating. I spent a lot of time trying to
troubleshoot a symptom a lot like yours. There are probably many possible causes for this problem
and the error codes, if you can find documentation, dont always point to exact problem.
Mine would run any length of time and go offline at random. It works perfectly now. Never shuts down. Grid tie runs just as good tied to PJ as utility grid.

The things i changed involved matching the PJ voltage output in center of grid tie voltage max min parameters and giving pj the battery power it needed to regulate it. The pj battery input now runs tight 25.4vdc min to 28.0vdc max. If i load battery bank to pull voltage lower than 25vdc then my grid tie will still go offline.  I am guessing but this might be caused by pj wave distortion since i altered voltage feedback to drive primary harder to target 239VAC instead of 224VAC where it was designed. This left less headroom for low battery voltage which in my case was solved by higher battery voltage in LFP batteries. This could also have been solved by adding turns to secondaries of toroids.  I didnt have luxury of adjusting gti parameters. (it was US gti emerson spv)
I only have single gti/6000lf pj setup and during normal day if gti is putting out more than loads you can see a flicker every second. This is anti island stuff and pj has to fill in. When loads are greater than solar you dont notice flicker. In short Battery bank voltage and stability along with output voltage matching made the difference.

Good luck with that!
Lighthunter

[oztules]

Lighthunter is onto it I think.

PJ is not designed for lithium, and the transformers I have found to be under done on the secondaries  or over done on the primary... so low bat voltage will cause trouble for the pj... add secondary turns or delete some/a  primary turn... secondary is easier.

I only use galvanically isolated inverters, so have no idea to the foibles of HF units... none what so ever.

............oztules

[lighthunter]

Quote " AC voltage is sitting at 234. This seems like a good voltage, since the grid tie inverter is rated for 211-264VAC."

I remember trooubleshooting from this exact point of view. Over and over i convinced myself....the pj output voltage is right on even through large load surges. It had me convinced that the problem had to be with GTI or wiring. Until i changed battery bank and the setup ran perfectly.
The grid tie faults didnt necessarily correspond with low battery voltage either, so i never figured it out that way.

From your voltages im guessing 7S LFP. If thats the case, theres an extremely good chance 8S will solve your problem. The PJ runs great on 8S. You can also change winding numbers and achieve this but another viewpoint to keep in mind is... if you can run the 24v inverter at 26 you will drive current and heat down and increase load capacity and less stress for your pj inverter. 
I doubt that changing parameters in GTI will help. I think what happens is the pj output wave gets clipped at the peaks causing distortion that bothers the GTI.  Unless you change winding numbers you will need to increase battery voltage or one other possibility is to lower pj output voltage by altering feedback and adjusting GTI parameters to follow. Of course this might affect efficiency of GTI.
I just about put my GTI on ebay but after connected to pj with 8series LFP i wouldnt sell it for 3times what i paid..$300.
You may already have battery monitor/management but if not and you want cheap i would check out CellLog8S $35 gets you ability to record everything that happens to your batteries and you can choose your own emergency shutdown limits with individual cell monitoring, only caveat is unequal drain but theres a fix.

Oztules if i would have spent the money for a proper size AGM or trojan fla no doubt i would never had a problem. How many AH of this type would i have needed to cover 2kw loads during clouds and stay above 24? I have so appreciated your thoughts and comments. Many of us are indebted to you and wouldnt have the equipment we do without your help. Thankyou!

Lighthunter

[davidwillis]

Thank you so much for the information.

I have read through this thread a while back, but most is over my head.  What is a 8S?

Also, how high can the voltage go on the pj?  I am thinking about running the voltage from 27 to 31.5V if the pj can take that voltage, and if it does not put my AC voltage over the limit of the Grid tie inverter.

the CellLog8S looks interesting, but why does it cause unequal drain, and what is the fix?

 I really hope the voltage is the problem, and it sounds like it is...

Thanks again.

[oztules]

David, at least 30v, and if you want more then use the 5v6 across the 10m resistor.. then it is unlimited

Light, I like FLA as they are cheap and forgiving. lithium is better at everything except price and longevity in case of over charge.... so I stay with fla.

How long for is the question.... and 2kw@24v is 80 amps approx....staying above 24 would be a big bank, but better to get the tranny right, and let it sink under at that kind of current to drive at 23v-24v or so... battery curves will tell you.

.............oztules

[oztules]

Antman... try this    http://www.anotherpower.com/board/index.php/topic,780.msg7498.html#msg7498

Use 5r6 instead for the gates, and put a reverse diode across them.

....oztules

[lighthunter]

Hi David ,

7S and 8S refers to 7 or 8 series cell. Sometimes you see a battery pack.
referred to as 3S2P meaning 3 cells in series and 2 in parallel. (3x 1cell voltage.
And 2x 1 cell AH capacity. LFP or Lithium Iron Phosphate (LiFePO4) is.
the kind i have and the voltage needs to stay between 2.6v/cell minimum to 3.6v/cell.
maximum. I have mine set to run from 3.1v to 3.5v but im not concerned about.
capacity. I'm usually only using top1/2 of capacity sometimes a lot less. My needs
are mainly concerned with leveling the variableness of clouds so my AC output watts
stay even to run loads without switching loads on/off. In your application if you have.
a large AH bank then you may want to use more of the usable range. You can do it by
using voltage triggers for full/empty battery but its critical. You absolutely must keep.
All cells above 2 volts or the cell will be junk. There isnt much capacity left below 2.8v
So better to stay away from 2 v as far as possible. The Full mark isnt as critical but 3.5v is
mostly full. Ive read that LiFePO4 chemistry is more forgiving about overvoltage than under.
Either one should be avoided. The tricky part is you are using these cells in a series configuration and the capacity of each cell is slightly different they always will be. If one cell gets full before
the other 7 and you are monitoring bank voltage, that cell can reach 4 volts in seconds with 60Amps of charge current, (ive watched it on bar graph) . So you have 2 choices, either top balance and stay away from bottom or bottom balance and stay away from top. You cant really do both though racers and vehicle applications do this with fancy circuitry but they also have higher failure rates. Balancing allows all cells to reach the full or empty threshold at the same time which allows the use of bank/pack voltage to indicate charge level. Even after balancing and calibrating voltage triggers its best to have a monitor that can detect a problem and shut off chg/dischg.

The CellLog8S unequal drain has 2 possible fixes that i know of, one is to connect a switch with lead wires to board. (jumper works too if you dont need to connect to computer) or you make buffer with 2 quad op amps configured as unity gain. I will post details.
I really like the record feature as i dont have balancer boards yet, i do it manually. The celllog allows me to see how each cell is performing through the day and if a balance problem exists. I also use it to (teach/program) my controller voltage setpoints.

Best of luck to you sounds like you have a great setup. As oztules said, pj will allow 30v for a few beeping seconds before shutdown without modification he refers to. Ive not had to modify mine but it seems many have.

Lighthunter

[lighthunter]

CellLog even drain info

 https://endless-sphere.com/forums/viewtopic.php?f=14&t=20142.

Cheers ,
Lighthunter

[lighthunter]

Oztules,  regarding FLA size. So changing the secondary turns on pj
in a sense allows smaller bank size for short duration high load... clever.
I guess i didnt realize that would have fixed the problem. Thanks!

Lighthunter

[davidwillis]

For some reason I was thinking you were talking about modifying the pj. 

I am running 28 100ah LiFePO4 batteries  7s4p.  I personally like the bottom balancing,  and balanced them all at 2.5V.  Then I just have the system set to stop charging at 3.5v, and stop the load at 3.0V.  I have used this setup for years with no BMS and I love it.  I do check individual cell voltage at times, but have never had any go out of range. 

I could go with a 8s, but that would put my voltage range at 24V to 28V, since the 24V is under 25.5, it sounds like that may cause an issue so I was thinking running 9s to put the voltage at 27 to 31.5.  I know when I was playing around with some FLA batteries it got the voltage up above 30V, but I don't remember exactly what it was before the AC voltage went too high and shut off the grid tie inverter.  I may have to play around with it a little to see which works best.

Hi David ,

7S and 8S refers to 7 or 8 series cell. Sometimes you see a battery pack.
referred to as 3S2P meaning 3 cells in series and 2 in parallel. (3x 1cell voltage.
And 2x 1 cell AH capacity. LFP or Lithium Iron Phosphate (LiFePO4) is.
the kind i have and the voltage needs to stay between 2.6v/cell minimum to 3.6v/cell.
maximum. I have mine set to run from 3.1v to 3.5v but im not concerned about.
capacity. I'm usually only using top1/2 of capacity sometimes a lot less. My needs
are mainly concerned with leveling the variableness of clouds so my AC output watts
stay even to run loads without switching loads on/off. In your application if you have.
a large AH bank then you may want to use more of the usable range. You can do it by
using voltage triggers for full/empty battery but its critical. You absolutely must keep.
All cells above 2 volts or the cell will be junk. There isnt much capacity left below 2.8v
So better to stay away from 2 v as far as possible. The Full mark isnt as critical but 3.5v is
mostly full. Ive read that LiFePO4 chemistry is more forgiving about overvoltage than under.
Either one should be avoided. The tricky part is you are using these cells in a series configuration and the capacity of each cell is slightly different they always will be. If one cell gets full before
the other 7 and you are monitoring bank voltage, that cell can reach 4 volts in seconds with 60Amps of charge current, (ive watched it on bar graph) . So you have 2 choices, either top balance and stay away from bottom or bottom balance and stay away from top. You cant really do both though racers and vehicle applications do this with fancy circuitry but they also have higher failure rates. Balancing allows all cells to reach the full or empty threshold at the same time which allows the use of bank/pack voltage to indicate charge level. Even after balancing and calibrating voltage triggers its best to have a monitor that can detect a problem and shut off chg/dischg.

The CellLog8S unequal drain has 2 possible fixes that i know of, one is to connect a switch with lead wires to board. (jumper works too if you dont need to connect to computer) or you make buffer with 2 quad op amps configured as unity gain. I will post details.
I really like the record feature as i dont have balancer boards yet, i do it manually. The celllog allows me to see how each cell is performing through the day and if a balance problem exists. I also use it to (teach/program) my controller voltage setpoints.

Best of luck to you sounds like you have a great setup. As oztules said, pj will allow 30v for a few beeping seconds before shutdown without modification he refers to. Ive not had to modify mine but it seems many have.

Lighthunter

[lighthunter]

Wow, i see. Ok so the number of batteries you would need to go to 8S would be.
a considerable expense. Personally i dont think pj could regulate AC
output voltage very well with 9S thats 31.5v when full im thinking AC voltage.
Would go high and turn off gti, then again it might work great. So far 8S is
working flawless im not sure what you see as problem there but i might be.
missing something. When i wrote 25.5v minimum for my bank voltage im using a different.
GTI and only 40AH LiFe. The size of your bank is going to allow pj to be less sensitive. If your bank is low then when GTI runs voltage will pick up quick.

If 8S wasnt enough you could always wind a few turns on the pj toroid and add to.
secondary. Since you have an established pack adding new cells is a bit of a chore
anyway. Shucks maybe adding the turns to pj toroid would be your quickest painfree.
solution. The holes are already open on those and i think you could add turns on top without.
disturbing original windings. Sounds like you have some good options/choices to remedy.
problem.

LH

[lighthunter]

David, with 6kw solar and 400AH 24v bank you could say goodbye to.
the grid. Ours 1/3 the size is knocking $25.00 off our electric bill, 5-12kw/day.
Nice, are you using
trackers too?

LH

[davidwillis]

This is actually my friends system that I am helping with.  The Grid tie system has taken his power bill down to just the monthly charge of $12 or so.  He actually lost 100 kwh when they did they zero everything out each year.  The idea with the batteries is to provide backup power when the grid goes out.  This should supply enough power to run his fridge freezer, and hid kitchen appliances.  Even more when the sun is out.  He is not using trackers.

I have a smaller grid tie system that I have been running on my home.  It is a 4.8kw grid tie system with a 48V pj 10,000.  I am running the batteries with 16s4p configuration with no problems, but I have a much older grid tie inverter.  I have run my entire home off grid for a few days with this, but since I have a zero power bill with the grid tie hooked up (in the state I live in my credit can pay for all fees, as opposed to my friend who lives in a different state), I use the grid and save the batteries.

David, with 6kw solar and 400AH 24v bank you could say goodbye to.
the grid. Ours 1/3 the size is knocking $25.00 off our electric bill, 5-12kw/day.
Nice, are you using
trackers too?

LH

[davidwillis]

we tried it today with the battery voltage at 26V, but that did not fix the issue.

The Grid tie inverter is syncing and starting, but shuts down again after a minute.

[oztules]

Does the pj have the inductor in it... if not it is lucky to run at all... after that I have no idea with hf inverters
.....but you do need the inductor I have found.

.........oztules