Pylontech US2000B

[greentangerine]

Anyone know which of the three battery packs are cells 0-4 and so on?

Not getting anywhere with Pylontech - six of my eight US2000s appear to be sick and I reckon I can salvage a few by moving some of the cell packs around.

[knighty]

Im pretty sure if the bms see's a high or low voltage cell it shuts the pack down... coukd this be your problem? One bad cell (or parallel cells) is lower capacity than the rest... so it's voltage drops quicker and the bms shuts the pack down?

I googled to see if there was a guid to checking cell voltages with a meter but can't find anything

I think your best bet is a full charge - check voltages

Then put a load on the cells and keep checking voltages


A google found a guy who split the packs of multiple units apart and rebuilt them to maje sone good packs/units

[greentangerine]

Yes, that seems the issue. Some of the packs appear ok so I can probably get a subset working by swapping. I know which packs/cells are bad in each unit but don't know how that relates to the physical layout of the unit.

[Stinsy]

Frustratingly I couldn’t find anywhere to manually access cell voltage. However if you take the negative lead off the PCB you can access the pack without the BMS in the way. You can then bench charge the pack at a very low C to see if you can awaken the sleeping cells.

[knighty]

now I'm on a PC I can see better

green board to the right is the BMS, those 3 connectors going into it will be the bms leads... try checking the voltages at those, see if you can find any low voltages

(that's assuming they're not paralleled at a cell level)


depending on that connector (it's most probably a standard connector)you could unplug them there and at the main cables and charge/test them with a balance charger/tester at that connector

do the packs remove easily to separate?