I don’t know Greg. I’m just reporting what the charger screen says. It’s possible that 1A is the maximum and the discharge program varies the rate to better simulate actual use. When you calculate it out that is the only thing that makes sense - UNLESS the “C” display is not MaH , but only total Ma used and you work that with the total time to arrive at MAh drawn from the pack. The manual only says the display is “C” and does not explain further.
It would be interesting to put an ammeter in series during that cycle and see exactly what the discharge rate is.
Thanks, Greg
I don’t know if I can do that or not - it’s a balance dischagre - each cell is connected directly plus the pack leads. Wired like this (4s)
That diagram isn’t quite right. What they call Pack Positive and Pack Negative is actually wired to the Battery plus and minus. All of these balance connections are BEFORE the PCB. In addition the Pack plus and minus are connected to the the main output of the charger. SO - I’m not exactly sure where the current is drawn from during discharge. Also, I’d need to un older something or make up another set of M/F connectors in order to have a spot to stick the ammeter in series.
Yep, with a balance charger, operating in that mode, you would need to tap in to each one.
One thing I do not know about balance chargers, is if they cycle through the batteries one at a time during charging, or if it can simultaneously charge all independently. I would be surprised if it can do that, because it either needs multiple charging chips or it multiplexes the sensing and charging currents among all batteries.
Michael probably has the answer.
Greg
I noticed tonight while doing another cycle that the discharge display does have a current indicator. It said .4A when the cycle first started.
Balancing happens simultaneously. There is a screen that shows cell voltages and you can see them all climb (or fall in discharge mode) together. They usually stay with .02V of each other during the discharge process. When the charge process starts they can be quite a bit different but usually end up within .01V of each other.
Cycle 2 charge took 114 Minutes to reach 16.39V The C Value was 1716 and the cell voltages 4.10 4.09 4.09 and 4.09
Cycle 2 discharge charge took 238 Minutes to reach 11.98V The C Value was 1586 and the cell voltages 3.16 2.96 2.95 and 2.97
From these results it looks like Cell #1 is not performing the same as the other 3.
It appears that the charging current is through the entire pack and it is just monitoring the individual cell voltages.
I thought these chargers could charge the cells individually, but perhaps not, just monitor for issues.
Greg
I’m quite sure it does more than just monitor because it can take a pack that has cells varying by several volts and balance them to within a hundredth of a volt. Can’t do that without some control over the cell. It might be variable loading rather than pushing current to each cell. You would need to research the chip that most of these chargers are based on.
EDIT: To add apology to Terry, the OP, for monopolizing your thread. I hope your original question has been answered and that this tangent adds some value.
Greg Elmassian said:
It appears that the charging current is through the entire pack and it is just monitoring the individual cell voltages.
I thought these chargers could charge the cells individually, but perhaps not, just monitor for issues.
Greg,
I beleive the balance chargers we typically use have a single IC with an analog Mux. The micro-processor monitors all individual cell voltages, and is programmed to control external pass transistors (P type Mosfets) for charge current input and additional Mosfets are used to bleed current whenever a voltage imbalance exists.
Michael