Quote:
Originally Posted by SpmP
I am working on a charger based on the ESP120 3kW PSU, in my configuration (28cells) I am using two in series. But there is no reason not to go to eight in series.
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It looks to me like the PSU does not allow you, at least via I2C, to set the maximum output current- just as JoeG mentioned. As I read it, you can enable or disable the output - but that's about it. Lots of information read back but minimal control.
So I think a couple of things would need to be changed in your design. The PSUs can still be chained together to get a higher bus voltage. I think an open source DC motor controller circuit would work to limit the current to a set value during the constant current phase of the charge.
The constant voltage phase, where the voltage stays constant and the current drops, is built into the PSU but that's only if the output voltage happens to match the battery pack. I didn't see an I2C adjustment for the output voltage. Is there an adjustment via sense resistors that I missed?
If the pack voltage does not match, it gets more complicated.
I have not looked at Jack's circuit - it may deal with all of this.