Idiot's guide to a self build battery

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Stinsy
Posts: 2758
Joined: Wed Jun 02, 2021 1:09 pm

Re: Idiot's guide to a self build battery

#701

Post by Stinsy »

MrPablo wrote: Tue Apr 04, 2023 6:23 pm Some progress made today - battery storage and clamping system built and installed.
I'll be getting the DC cable, lugs and a crimping tool ordered today then I should be able to get it all wired up.
Simple OSB box, bolted to the wall with two supports for belts and braces.

Image
Image

All the material was left over from other projects, OSB might not be as attractive as plywood but I'm not going to break into a full sheet just for this.
Once I'm finished up, I plan to put a cover of some sort over the front. Shame I don't have a length of plexiglass or similar.
I’m liking the compression system!
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
ALAN/ALAN D

Re: Idiot's guide to a self build battery

#702

Post by ALAN/ALAN D »

Why 17 battery cells. ?
Will your inverter / battery charger be able to charge the system
MrPablo
Posts: 273
Joined: Mon Oct 17, 2022 1:26 pm

Re: Idiot's guide to a self build battery

#703

Post by MrPablo »

ALAN/ALAN D wrote: Tue Apr 04, 2023 9:35 pm Why 17 battery cells. ?
Will your inverter / battery charger be able to charge the system
Honestly its all a bit of an experiment.
The inverter can charge up to 58v, so 3.41v a cell. That's enough to charge to full if needed but it'll take longer than pushing to 3.5v+.

The benefit is that I get more voltage than the 15s Pylontech, so at the 65a inverter limit I should get about 400w more power.

Of course, it might all fail to work properly. If that happens, I'll disconnect the 17th cell and flog it to someone else.
10x 405W JA Solar panels (4.05kWp) @ 5 degrees
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
0.6kW Ripple WT
64kWh Kia E-Niro
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Krill
Posts: 382
Joined: Fri Sep 02, 2022 4:38 pm

Re: Idiot's guide to a self build battery

#704

Post by Krill »

Planning to sell the Pylontechs MrPablo?
Solar PV: 6.4kW solar PV (Eurener MEPV 400W*16)
PV Inverter: Solis 6kW inverter
Batteries: 14.4kWh LiFePO4 batteries (Pylontech US5000*3)
Battery Inverter: LuxPowertek 3600 ACS*2 battery inverter
WBS: 8kW Hunter Avalon 6 Multifuel burner (wood only)
MrPablo
Posts: 273
Joined: Mon Oct 17, 2022 1:26 pm

Re: Idiot's guide to a self build battery

#705

Post by MrPablo »

Krill wrote: Tue Apr 04, 2023 10:18 pm Planning to sell the Pylontechs MrPablo?
They'll be joining an existing pair of 3.5kWh Pylontechs at a friend's house. Selling them to him is funding this - more capacity for less money is a no brainer!

I did contemplate doing a Joeboy and having Pylontechs plus DIY, but 25kWh of storage is overkill for me. For now anyway!
10x 405W JA Solar panels (4.05kWp) @ 5 degrees
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
0.6kW Ripple WT
64kWh Kia E-Niro
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Krill
Posts: 382
Joined: Fri Sep 02, 2022 4:38 pm

Re: Idiot's guide to a self build battery

#706

Post by Krill »

Probably for the best, I'm broke as it is right now!

Best of luck with the rest of the set up :b
Solar PV: 6.4kW solar PV (Eurener MEPV 400W*16)
PV Inverter: Solis 6kW inverter
Batteries: 14.4kWh LiFePO4 batteries (Pylontech US5000*3)
Battery Inverter: LuxPowertek 3600 ACS*2 battery inverter
WBS: 8kW Hunter Avalon 6 Multifuel burner (wood only)
marshman
Posts: 614
Joined: Thu Jun 17, 2021 7:58 pm

Re: Idiot's guide to a self build battery

#707

Post by marshman »

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Last edited by marshman on Sun Jun 11, 2023 1:11 pm, edited 1 time in total.
MrPablo
Posts: 273
Joined: Mon Oct 17, 2022 1:26 pm

Re: Idiot's guide to a self build battery

#708

Post by MrPablo »

Hi Marshman,

Good point re. the insulator between cells, I had looked at that previously but clearly I forgot about that yesterday.
I have some plastic membrane which I'll put between each cell today.

Re. the OSB end caps, you could well be right, but I intend to monitor it and add an additional aluminum plate on the outside if needed.
10x 405W JA Solar panels (4.05kWp) @ 5 degrees
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
0.6kW Ripple WT
64kWh Kia E-Niro
MrPablo
Posts: 273
Joined: Mon Oct 17, 2022 1:26 pm

Re: Idiot's guide to a self build battery

#709

Post by MrPablo »

A little more progress this evening, balance leads are now done.
Image

I've crimped the lugs on the BMS cables, plus the main positive & negative leads. I'm off to an ale festival tomorrow so no more progress until the weekend but so far, so good.
10x 405W JA Solar panels (4.05kWp) @ 5 degrees
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
0.6kW Ripple WT
64kWh Kia E-Niro
ALAN/ALAN D

Re: Idiot's guide to a self build battery

#710

Post by ALAN/ALAN D »

I would suggest that the Black B.M.S. cable is not tye rapped in the bundle with the positive cables from each cell. B.M.S. fault and lots of current could flow. I have also soldered a fuse / holder to each cell cable.
I might be a bit over the Top. ?
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