powerB
New Member
- Joined
- Feb 17, 2021
- Messages
- 6
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??
Is charging at a constant voltage bad?
In another thread one person's response to a similar situation was: the PSU leads could be the problem (because they're way too thin)?
Am I misunderstanding?
Here are three pictures to show whats going on:
Step 1: set the max voltage to 3,65v
Step 2: set the max current to 10A (by clamping the two leads to each other, as per PSU manual)
Step 3: connect the cell and watch this happen: the PSU is in the CV mode, the amps are down to 4,377A and slowly seem to be dropping
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??
Is charging at a constant voltage bad?
In another thread one person's response to a similar situation was: the PSU leads could be the problem (because they're way too thin)?
Am I misunderstanding?
Here are three pictures to show whats going on:
Step 1: set the max voltage to 3,65v
Step 2: set the max current to 10A (by clamping the two leads to each other, as per PSU manual)
Step 3: connect the cell and watch this happen: the PSU is in the CV mode, the amps are down to 4,377A and slowly seem to be dropping