I need a source of power for my next project, and I'm considering using Li-Ion batteries. However, these sometimes need special chargers that are not readily available.
Does anyone here have experience with Li-Ion batteries?
Can I use one purchased off eBay? (often posted as replacements for cellphones/PDAs)
I have seen the SparkFun LiIon cell, but it's around $30 plus charger, and I'm really hoping not having to spend all that much.
Separate question: I have a 3.7 LiIon cell from an old iPod, but it has three wires (black/red/white) coming out. What does the white one do? Is there a known charger for this kind of cell?
The white one is for the internal sensor (thermistor ?) which links to the charging circuit to tell it to stop charging before it explodes / bursts into flames.
Its possible (I never owned an ipod) the charging circuit is built into the ipod and the charger itself just feeds out DC.
thermistor, huh? interesting
And yeah, the charging circuit is somewhere on the iPod logic board...
I guess for my project it might be easier to stick to normal eneloop rechargeables, since charging LiPo/LiIons seems a bit like rocket scienece, or at least requires expensive equipment.
What kind of circuit would you recommend for a combined charge/discharge operation? Meaning, the device should be able to be charged while in use, but also operate on batteries alone.
