Hey everyone! I'm new to the DIY power station scene, and I've run into a bit of an issue with my charging setup. I've got a jkbms paired with a 20amp 12v charger that's supposed to output 14.6v, but the charger keeps shutting off and showing 'FULL' at just 13.2v. The BMS is also indicating 13.2v. Am I missing something or doing something incorrectly? Looking for any advice!
2 Answers
Is your jkbms programmable? It might be worth checking the settings to ensure it’s configured to recognize a full charge at 14.6v.
Where are you getting the 13.2v reading from? If it’s from the battery terminals while the charger is connected and still showing 'FULL', then the charger itself might be faulty. That voltage is really low, almost indicating a 20-40% state of charge. If you can, consider returning the charger.
On the other hand, if the terminals are showing 14.6v when the charger says 'FULL', but the BMS is reflecting only 13.2v, it suggests the BMS could be cutting the charge short. This could be because of a misconfiguration or perhaps an imbalance among your battery cells, which could cause one cell to hit its cutoff voltage before the others.
You might want to check the voltage across each cell to see if one is around 3.65v when charging stops; that could be your issue!