Ok so if you mean the voltage is lower at the cells than the PS that's normal. There will always be some voltage drop.
I don't understand this. 3.6 volts?
It's probably not calibrated and might not be as accurate at the lower voltage. Not familiar with that meter so I really don't know.
This has me wondering if it's because the IR of those cells is lower that the EVE or other larger cells.
Do you mean 3.36 volts or something?
And that's while charging? Strange. Something is not right obviously but I don't know what it could be. Can you post a photo?
Here is how it's supposed to work:
The voltage of the power supply must be set to 3.65 volts before connecting to the cells.
When you initially connect the power supply to the cells, the voltage displayed on the power supply will go down and the current will output close to the full current the power supply is capable of. Towards the end of charge the voltage of the power supply will increase and the current will start to drop.
At this point the power supply should switch from constant current to constant voltage mode. It's very important to take a voltage reading at the cells terminals with a DVM during this process to be safe especially towards the end of charge. Eventually the voltage displayed on the power supply will be 3.65 volts, and the cells, and the current will taper down to zero. It's ok to disconnect the power supply when the current is .500ma's or less.
Here's exactly what I did......
Disconnected leads from battery.
Turned on PSU
Set VOLTAGE to 3.65v
Set Current knob to Maximum
Turned off PSU
Connected Leads to battery.
Turned ON PSU
PSU has a green light next to the voltage display (indicating constant voltage mode)
Current goes to between 5A and 6A
Battery finally reaches 3.377v...then the voltage on the meter at the terminals begins to fall back slowly...eventually stopping around 3.360v.
It's almost as if these cells have a cell protection circuit in them set at 3.377v....which makes no sense.
My PZEM meter now says I have put 188Ah into the cells but they are in Parallel so I'm not sure the significance.
Meanwhile, Watt Hours is only 650 (out of 1440 because this is a 120Ah battery)
Not sure this set of cells will ever reach 3.65v. If not by tomorrow it's Return time (yet again)
At least this set of cells is balanced and the resistances were good. Baffling what's going on. Magic.
(Or bad PSU?)
The kicker is that even when they are going backwards in voltage....my clamp meter STILL says current is going to the battery....unless it's actually saying current is LEAVING the battery?