![\"\"](\"https:\/\/i0.wp.com\/www.comvolt.com\/eblog\/wp-content\/uploads\/2023\/09\/PXL_20230829_184301349-scaled.jpg\")
<\/a>Getting the top off is touch<\/p><\/div>\n
<\/p>\n
<\/p>\n
BMS Failure, Cells or Wiring<\/h2>\n
In modern LiFePo batteries, you can break it down into three parts, Cells, Wiring and BMS.\u00a0 Once the top is removed, the basic troubleshooting can start. Before getting started it is interesting to note this is a pretty high-quality battery, Prismatic cells..solid. Epoxy molded to keep things from moving around..solid.\u00a0 No corrosion or dust since the case is sealed from the elements..not much to complain about.<\/p>\n
If you took a good look at the picture above, you will notice that the voltage measurements and the wiring look good.\u00a0 Since the cell voltages add to 13.2V and we don’t see any loose wiring, the likely culprit of the failed battery is the BMS.\u00a0 There is a lot of information on the internet explaining what the BMS does, but basically, it makes sure the cells are balanced and it cuts off the connection to the LiFePo cells if there is a fault condition like too cold, cells are under-voltage, charger is trying to overvoltage the cells.\u00a0 In this case, the BMS seems to be keeping the cells disconnected even though there are no real fault conditions.<\/p>\n Well, the big clue are the red heat sinks.\u00a0 To get to get it the BMS the way we did involved more caveman technics.\u00a0 A dremel cutting tool is how we did it.<\/p>\n Not sure how long the link will be active, but this is the one…<\/p>\n https:\/\/www.amazon.com\/DALY-LiFePO4-Protection-Balance-Battery\/dp\/B08PFPNNJG?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&smid=A22QWF3YLLYB17&th=1<\/a><\/p>\n Hope geeking out on a LiFePo battery was fun for you.\u00a0 It was for us, because we love digging deeper.\u00a0 If you have any questions or general comments please email us at info@comvolt.com.<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Once in a while we post slightly off topic findings that we think will be interesting\/unique information for readers.\u00a0 This post is about the very popular Renogy LiFePo battery with built-in Bluetooth.\u00a0 Even though we don’t provide solutions for these … Continue reading <\/a><\/p>\nWhat BMS Did They Use?<\/h2>\n
<\/a>Again, please let us know if you have a better way to get to this.\u00a0 With some more cutting and prying, we got the BMS out.\u00a0 Sure enough, it is a standard Daly 4S 50A charge\/100A discharge BMS you can get almost anywhere. We will follow up this post will a schematic extraction of the BMS.\u00a0 Why?\u00a0 No good reason.\u00a0 These are so cheap it doesn’t make sense to try and repair it, but we will do it to understand why they are failing.\u00a0 If you have read this far and actually took apart your battery to find a failed BMS, just buy a new one for about $50.<\/p>\n<\/a><\/p>\n