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The more you describe those batteries, the better they sound!  I just looked on ebay and found nothing like the bank you bought, and those I did find for sale were pricey for not too high AH rating.  Any chance your seller still has some like yours for sale??

Also, 48v powerjack inverters alarm at 59 and shut down at 60 volts so might want to adjust for that.  (22 cells instead of 23 would give you a range of 50-59 volts.  just a thought)   
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Hi Welshman,
I'm jealous of your battery bank.  Did you mention the AH rating?  I'm still using sla batteries for at least 5 or 6 years, until these die.

Did your question about the mosfets get answered?  I didn't see it if so.  I'm interested in the answer myself.
Are the hy3810 fets currently used by powerjack good ones?  Better than the 4110 fets in my older 15kw?  Is there a better choice than either?  I wonder why powerjack switched?

Good luck on your project!

lithium-titanate has a c20 charge rate, cycle count of 20,000, they can be squashed, drilled into and blowtorched and no harm will come to the person doing it. they can not set fire and can not explode ever, safest battery on the market. cell nominal voltage is 2.3 , charge is 2.7 and cut off low voltage is 1.7. in each series there are 23 cells, and 4 series in parallel. giving nominal voltage per series of 52.9, charge voltage of 62.1 and low voltage cut off at 39.1.

Making all those voltages ideal to the inverters specifications. The inverter low voltage cuts off at 40 volts, which is above the batteries low voltage specification, automatically keeping them safe. no extra under voltage protection needed. Also, no equipment feeding power into the dc; inverter, solar and wind, is going to be able to provide more than the batteries 62.1 charge voltage, again automatically keeping them safe from over charging.

I believe the batteries are only 30 AH, but I have no documentation stating this. I was only told, however due to the size of them I can believe they are at least that. i'm unable to even identify who makes the product, it appears to be specialist aircraft style design. However, the performance of these batteries is amazing. They can cope with huge amounts of currents in bother directions, which in itself is a safety risk, so fuses must always be used. They have a very impressive power curve, almost acting like full right down to the last drop of juice in them. right down at 42v I can pull a 6kw load without it dropping the voltage. They don't seem to jump like the lead acids did, just a steady drop in voltage increasing or decreasing speed, fluidly with load change.

To give you an idea what they are like, they out perform the original 16 x 130AH SLA's I had. Were getting twice the amount of uptime between needing to topup with generated power and have reduced the amount of time the generator is running, we're noticing the saving in fuel with them.
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Hi Welshman,
I'm jealous of your battery bank.  Did you mention the AH rating?  I'm still using sla batteries for at least 5 or 6 years, until these die.

Did your question about the mosfets get answered?  I didn't see it if so.  I'm interested in the answer myself.
Are the hy3810 fets currently used by powerjack good ones?  Better than the 4110 fets in my older 15kw?  Is there a better choice than either?  I wonder why powerjack switched?

Good luck on your project!
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Steve / Re: My Scratch Pad
« Last post by MadScientist267 on December 01, 2019, 11:37:37 pm »
Not bad. And I don't know why I'm not getting the notifications on this... Sorry

With the truck gone and a couple of moves, new(ish) relationship, and the fun that goes along with all of that and then some lol...

Been fairly busy but I think it's all finally starting to slow down a bit. Hope to kinda get back into the electronics end of things sooner than later, tho right now it's kinda a "answer in need of a question" lol

Last project was the charger and as implemented at least, really requires the large(r) batteries to complete the dev phase, which of course no longer exist... So there's nothing on the table right now, just the desire to mess with things lol
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That looks like a nice find.

I would love to see the raspberry pi controller build documented.
I have a similar project upcoming.

will provide all findings.

what I have so far is a raspberry pi 3 B v1.2 running windows 10 IOT and a universal windows application written that communicates with a peacefair energy monitor using Modbus protocol over rs485 via a cp2102 chipset ttl and a rs485 to ttl converter plugged into a USB port on the pi.

the GUI on the pi output via 7" hdmi touchscreen shows the various settings for the conditions in which the generator starts and shows realtime voltage and amp values off the peacefair module with 3 graphs to show the past 2 minutes of values. it logs the data to sd card every 5 seconds.

I also built in a webserver in the application so that settings can be remotely displayed and changed.

the application is written with visual studio 2019 and written to run on arm or x86/64 I will post the solution.




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Users Projects / Re: Going off-grid in Idaho
« Last post by dochubert on November 30, 2019, 09:09:57 pm »
Thanks for that link Wolvenar!  Hopefully won't need it. 

Life is good.  That 2015 style 15kw powerjack I got on craigslist locally is now powering the house.  It is one of the 3-transformer models like my original 15kw (currently DOA).  Seems to be reliable, its quiet, and it showed up just when I needed it.

All the roof solar panels are now hooked up and producing!  On good sun days (for a november winter's short days), the batteries get fully charged with some left over to dump load into water heating.
On not-so-good-sun days, (snowing yesterday) I shift half the house back onto the grid.  Even cloudy days provide enough charging to handle half the house.

Hi Pete.  That alternator charger sounds perfect for your situation.  We're not as economical with power as we should be so we use the grid as back up instead of a generator.  At least as long as it lasts.  When they shut it off for good we'll get suddenly efficient and thrifty with power use I suspect.  Until then this setup should do the job.  I have a couple of generators but haven't messed with them in some time.
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That looks like a nice find.

I would love to see the raspberry pi controller build documented.
I have a similar project upcoming.
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Users Projects / Re: Off grid water heating project
« Last post by Solarnewbee on November 28, 2019, 09:48:14 am »
Hey guys!

Here’s my home made dump load for my windmill. Haven’t gotten that up yet. That’s next trip. Philippines is a long way off.

I believe Pete drew a mud map of this delta arrangement. I was thinking 3 phase would work best with a delta and he confirmed that and 1 ohm was the smallest I could get. They are 100 watt and with the heatsink compound and huge forced air cooled heatsink it should work. I have a 24v battery charger now so I guess I could test that theory. These were 5 for $4 so pretty cheap.  2nd set kicks in to halve the resistance if necessary. Heatsink came off an inverter control board for a mini split hvac unit. I used to get lots of these but they don’t send the heatsink anymore. Hell they don’t even give you new isolation feet for the replacement compressors either.

Maybe someone could line up some of these in a row on a heatsink like this from a scrap yard find until they get the right resistance and wattage and strap on some fans. I used nylon all thread and nylon nuts. Had more fans on it but those little fans don’t have a drop height if you know what I mean.

Good luck experimenting!
If it’s there, may as well use it, right?

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In case anyone is wondering, the inverter is still going strong without any replacement parts needed yet. In use daily as a mains power supply.
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Update.

Got some LTO batteries, been running with them for a couple of months now and they have changed everything. Charge amazingly fast, ZERO fire or acid hazard.

I got tired of exploding lead acid batteries and needed to eliminate the dangers with them. I looked on ebay a few months ago and found these for sale. When I collected them I discovered they were aviation batteries and had been submerged in silicon oil their entire life. They were pristine.

I matched the number of cells to the inverters range of power, they can never over charge and they can never under volt.

Worked out amazing and was cheap.

Currently working on a raspberry pi to replace the generator controller. using peacefair pzem-017 module to monitor the batteries.
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