10kWh LifePO4 DIY Battery Addition..... Here is my write up.

jasgrif11

Are you just purchasing standard M3 self tapping screws?

on_the_roots

https://www.boards.ie/discussion/comment/121997717#Comment_121997717

Under normal operation, for sure. But what if for some reason the cell's temp raises relatively quickly? Until the sensor on the busbar detects, it might be too late.

The terminal goes deep into the cell, so this is far more precise measuring the temp from there.

SD_DRACULA

https://www.boards.ie/discussion/comment/122000117#Comment_122000117

I can't see individual cell temp reading anywhere on the jkbms so not sure it's even doing that (unless not being displayed to the user) plus you're reading the busbar not the terminal.

I have seen this widely used online so I would say it's safe to do, I have even seen it on the prebuilt battery packs that have the welded busbars.

oaklands

I drilled a 2.5mm hole in the busbar using a metal drill bit, then used an M3 tap drill bit to create the M3 thread. Then all that is needed is a very short M3 screw.

For Temp: I put each of the 4 JKBMS sensors between the foam padding. So that covers 8 cells but isolates the other 8.

unkel

https://www.boards.ie/discussion/comment/122000595#Comment_122000595

That is exactly what we did too with the busbars. Part of the reason is that the batteries were going to be mounted near the ceiling of a shed and the (custom made solid copper) busbars were hard enough to get onto the cells without the added complication of the balance wires, so we had the latter attached first

Evd-Burner

Hi All, I need a little help. I purchased everything I needed to build a Seplos managed 16s2p (calb) cells battery with a ME3000SP inverter 13 months ago.

I bought prematurely as there was a body of work I needed to complete prior to install, that body of work kept getting delayed and was finally completed in September gone, I had planned to get the battery up and running by end of October and started the fully charging and top balancing process. My cells are now sitting idle for 6 months, I just did a voltage test, see attached image.

Should I recharge and balance them all?

My batteries are located at the back of my garden office in a shed section, I noticed today that there was some dew on the cells, I suspect this may have occurred due to excess moisture in the area after the door shutter was left slightly up and a decent amount of rain water got in, cells are not on the ground, thoughts?

The battery is now the focus to get up and running by the end of this month at the latest.

unkel

https://www.boards.ie/discussion/comment/122000860#Comment_122000860

You left the cells fully charged, which is not a great idea if leaving them for so long. But not to worry too much, these cells are very strong and will likely be fine. Those voltages might look wildly different to you, but in fact they are very close together as even your lowest cell at 3.348V is still 90% charged and anything at or above 3.400V is 100% fully charged.

If you have the time, you should put them all in parallel and charge them up until they are all at 3.650V. Then rebuild the battery into 16S and start using it. Or leave them as is, sell your Seplos, buy a JK BMS and it will do the balancing for you

Evd-Burner

https://www.boards.ie/discussion/comment/122000889#Comment_122000889

Cheers Unkel, yeah I really hadn't intended to leave them long at all, it was just a case of wiring up and connecting everything to get it going but a few things came up with family and work that soaked up all my time and before I knew it 6 months had passed.

I'll wire them up in parallel tonight and leave them for a week to balance out so. Will stick with the Seplos for the time being as other wise I fear I may end up further delaying, I have time now with work not busy but that changes come May.

Any thoughts on the Dew forming on the cells?

on_the_roots

Can someone confirm this is a good bi-directional DC Circuit Breaker to use between Inverter/Battery? I tried to find the datasheet of the model (HSM1PV-125) but didn't find anything online.

This is also quite cheap in Amazon UK (€25,00), so wanted to confirm first.