I've got a simple 4S 100Ah battery sitting on my table, waiting to be top balanced for the first time. I am a novice when it comes to this stuff, but I've done a lot of reading and researching and have downloaded the Tutorial about balancing LiFePO4 with a 10A power supply. I think I have a good grasp of the important concepts but I am not sure if I'm doing everything right, though...??
The individual cells each measured in at 3.30v and I've hooked them up in parallel. I've decided not to do the pre-charging but instead go straight to the balancing. So I've taken the following steps:
- set the max voltage of the PSU to 3,65v (nothing connected)
- attached the positive (+) and the negative (-) clamps together to then dial in the amps (set to 10A)
- only after that is done clamp to and connect the battery terminals
...the PROBLEM (if it is one): the PSU display shows that the PSU is in the CV (constant voltage) mode, the display shows a permanent 3,65v and the amperage has dropped to around 4,0-4,2A and seems to slowly slowly decrease over time.
Now I'm really wondering whether this is correct?? I thought LiFePO4's needed to be charged up to 3,65v with a constant current?? Whats happening therefore seems to be the exact opposite. Or am I misunderstanding?
Here are three pictures to show whats going on:
View attachment 37417 Step 1: set the voltage to 3,65
View attachment 37418 Step 2: clamp clamps to each other, as per instructions, and set the max current to 10A
View attachment 37419 Step3: connect the cell. The voltage displayed remains at 3,65v, the current is ony at 4,377... and the CV light indicates that I'm charging with a constant voltage while I thought I should be charging at a constant current