I recently changed my 10s board from charging with an Imax B6 charger to charging with a BMS. I picked up a 42v 2a charger from ebay. And one major thing I’ve noticed is that it takes way longer to charge than it should. The battery pack on my board consist of 2 5s 5000mah batteries connected in series, both wired up to a BMS. Now, if the charger is sending 2a into the board, then shouldn’t the board take 2.5 hours to charge (since 5ah/2a = 2.5)? Instead it takes 5 hours. Can someone explain what’s going on? I’m so very confused.
Happy to provide any photos or links if anyone can help me figure this out
Your charger only outputs 2A when there is high enough voltage differential. As your battery voltage gets closer to full voltage, the actual charge current decreases. At near full capacity it is going to be less than 1A. Cutoff is usually around 500mA for most chargers