Charging A123 M1 Cells?

[BrianG]

I'm curious to know how the Lipoadaptor works.

A traditional lipo charger charges at a constant current until the cells reach 4.20v per cell. Then the charger switches to contant-voltage mode and charges at a steady 4.20v until the charge current dwindles down to ~0.1A.

A typical peak detection charger is simply a contant-current charger. The output voltage simply goes as high as needed to push the desired charge current through the batteries. Another circuit monitors (but does not limit) the pack voltage until it starts to drop. Then the charger stops.

Since the lipo adaptor hooks to a peak-detection charger, does that mean it never charges in constant voltage mode? If not, then wouldn't the M1 cell(s) not get the full charge due to the missing CV stage? If it does, how does THAT work?? Once the lipo adaptor hits 3.6v, it would lock the voltage. Then the battery should start drawing less current just like lipos. But since the constant current charger is still trying to force the charging current through it, the voltage will go higher and higher and higher until it hits the limit. This extra voltage and current (don't forget, Li cell current should be dropping here) has to go somewhere since it's not going to the battery. And the lipoadaptor doesn't look near big enough to shed that kind of energy.

I know it must work, I'm just confused how it works. And if it does NOT charge the constant-voltage portion, then the cells aren't getting charged to the full capacity. Or are the M1 cells different from other Li technology and not need the CV stage?

[jhautz]

from my understnding that is exactly how the lipodapter works. It just skips the constant voltage stage and only charges them to 90%.

Its a simple device. Its just having to understand what the number of blinks mean and pressing the same button the correct number of times at the right times in a startup sequnce every time you charge a battery with no feedback from the device as to if you did it correctly sounds like a mistake waiting to happen to me.

If sure it works fine if your carful.