Idiot's guide to a self build battery

[Stinsy]

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.




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!

[ALAN/ALAN D]

Why 17 battery cells. ?
Will your inverter / battery charger be able to charge the system

[MrPablo]

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.

[Krill]

Planning to sell the Pylontechs MrPablo?

[MrPablo]

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!

[Krill]

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

Best of luck with the rest of the set up :b

[marshman]

__

[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.

[MrPablo]

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


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.

[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. ?