|
I still recommend this 100% I didn't have to charge my kindle ever since then, the battery isn't having any problems.
zxczxc:
since the circuit is attached directly to the battery, the kindle mainboard doesnt "see" it at all. You can charge it via AC as usual. The charging current will be the sum of the mainboards current and the one from the solar regulator. If you attach a very large solar cell, it could cause your battery to overheat, but the mainboard would recognize that and reduce the current. The solar circuit will always charge according to its built in charging curve, of course limited by the amout of power provided by the cell.
idoit:
I don't know why you want to have the ability to disable the charging circuit. It will never overcharge, the IC will take care of it. But if you want to disable it you can always install a switch in one of the lines going to the battery or the cell. As far as I remember the IC has an enable/disable port that has to be left floating or pulled to gnd in order to enable/disable. You could try to attach that port to the charging indicator led, to disable charging while the LED is lid. (don't remember which way it works..)
You also could disable charging by software: The battery management chip measures the current drawn from the battery, to disable charging write a script that uses (CPU) power to consume as much energy as the solar cell provides.. Under heavy load the kindle can consume about 300 mA (indexing, frequent screen updates, Wifi), thats more than any solar cell that fits in the backcover can provide.
One last tip: By now there is another IC from ST called SPV1040, that does pretty much the same thing, but also comes with mpp tracking. I would love to try one of these out, but they don't want to send me an engeneering sample.
Maybe one of you guys is lucky!
Have fun!
|