Idiot's guide to a self build battery

[Andy]

Cheers guys. I'm slowly re reading it all again. There is a lot to take in as usual.

[Joeboy]

Cheers guys. I'm slowly re reading it all again. There is a lot to take in as usual.

No worries, regardless of the size of battery stack I will only ever see a max charge/discharge of 100A due to PV array size and the goodwe hybrid inverter self limits. Scaling up battery pack size should add longevity as the packs not having to work quite so hard.

[Caesium]

Great to see well done indeed!
When are you making THE connections?

Today Everything's hooked up except pushing the plugs into the Pylons and throwing the isolator switch. I'm just waiting for some voltage indifference to sort itself out. My DIY pack stayed at 49.35v or so overnight with the balancer in, my Pylons are currently at 49.8v, so there's quite a lot more charge in the Pylons.

This will drop in the next few hours as my house consumes the energy so when they're within a tenth of a volt or so I'll take one last multimeter reading and make the final connections. There's a 100A fuse inline with the master connection as well so I'm not really expecting much excitement, which is probably for the best

[Joeboy]

Great to see well done indeed!
When are you making THE connections?

Today Everything's hooked up except pushing the plugs into the Pylons and throwing the isolator switch. I'm just waiting for some voltage indifference to sort itself out. My DIY pack stayed at 49.35v or so overnight with the balancer in, my Pylons are currently at 49.8v, so there's quite a lot more charge in the Pylons.

This will drop in the next few hours as my house consumes the energy so when they're within a tenth of a volt or so I'll take one last multimeter reading and make the final connections. There's a 100A fuse inline with the master connection as well so I'm not really expecting much excitement, which is probably for the best

Exciting yet casual, impressed!

[Joeboy]

Well thats made a royal mess of my nice neat battery stack



But its all connected and still no explosions. Just the one orange LED on it which I guess means power. I could try applying a small surplus voltage to one of the cells and see if it balances it back out, but otherwise I've no idea if its working yet, it has no balancing to do

Great to see well done indeed!
When are you making THE connections?

Caesium, are you blanking off that 16th Balance wire? I heatshrunk mine.

[Caesium]

Yes I got a bit carried away soldering those

I've cut the terminal off now, also there's no fuse in the fuse holder attached to it, but yeah I may as well reclaim that holder, cut it right back down to the multiplug wire then tape it up or something.

[Joeboy]

Yes I got a bit carried away soldering those

I've cut the terminal off now, also there's no fuse in the fuse holder attached to it, but yeah I may as well reclaim that holder, cut it right back down to the multiplug wire then tape it up or something.

Good man, would not have wanted it to arc. I test fitted my multiplugs the other week and they were quite tight. I will connect the balance wires to batteries with multiplugs disconnected and balance wire ring terminals taped over. Also going to track down some sort of led indicator with numerals too for the visual. If anyone finds something like that, please let me know. What Amp blade fuse are you running in the holders?

[Caesium]

I will connect the balance wires to batteries with multiplugs disconnected

I did this, you do get a bit of a spark on the B- side of the plug when pushing it in but its just a cap charging on the board I expect; I've done it twice now on this board, same both times.

What Amp blade fuse are you running in the holders?

5A in most, except when I ran out and had to switch to 10A for the last few I kind of thought any fuse is better than no fuse Although I suspect the wires into the multiplugs are rated for less than 10A, perhaps not even 5, hmm. Not sure.

I'll get some more 5A on order

[Joeboy]

I will connect the balance wires to batteries with multiplugs disconnected

I did this, you do get a bit of a spark on the B- side of the plug when pushing it in but its just a cap charging on the board I expect; I've done it twice now on this board, same both times.

What Amp blade fuse are you running in the holders?

5A in most, except when I ran out and had to switch to 10A for the last few I kind of thought any fuse is better than no fuse Although I suspect the wires into the multiplugs are rated for less than 10A, perhaps not even 5, hmm. Not sure.

I'll get some more 5A on order

Good to know, I am going to run without blade fuses. Might fit later.
Are ye there yet?

[Caesium]

And we're connected

Had a clamp ammeter around my main connections back to the Pylons and saw a peak of 1.1A flowing when I flicked the switch, and that quickly settled down to 0.6A so there wasn't much indifference between voltages.

Turned the kettle on to test, which resulted in a peak of 11A coming out of my DIY stack. So my 25mm cabling should be absolutely fine