Salvaging Cell Phone Batteries

[budder8818]

So I have about 6 cell phone litium ion batteries rated at 3.7v each. 3 are rated at 1000mAhr and 2 950mAhrs. So I understand all these ratings and what they mean. But is there a max current draw I can get out of these batteries. I would like to be able to drive two small motors. I think I will need 800mA draw at most. So my question is: how can I find the maximum discharge current without having to worry about the batteries catching fire or exploding. btw, I am charing them with an old cell phone so I have that covered.

The batteries are:
LG Lithum Ion Battery 3.7v 1000mAh (LGIP-A1000E)
Kyocera 3.7v 900mAhr, Model # TXTBAT10009

I've tried searching for the data sheets but I can find them.

Thank you

 

[VSMVDD]

1000mAph means it can supply 1 amps for 1 hr and maintain the voltage rating
then the voltage will drop off for lithium very fast {avalanch}

ma per hour mAph = 1000

from full charge

most lithium cells can be reused from phones for other projects

you must remove there charger boards and monitors electronics
most phone makers build into there cell

then condition the cell again
for lithium charge fully using constant current around 75ma for a 1000maph cell
for 20 hrs

then a 'rapid discharge and recharge using pulse method'
dump there charge then pulse charge maybe 2 or 3 times

most well designed phones do this .. task ... every 10 or times you charge it
and you would never notice.,.. too prolong the life of a cell
to get them to supply anywhere near the best if they are to be 'trusted'

however most cells can including lithium can regain capacity using conditioning methods

 

[RCinFLA]

What you won't find in the specs is the equivalent series resistance of the cell. A new 1000 mA LiIon for a cell phone will have a series resistance of close to 0.1 ohms. Just about all cell phones batteries have safety circuitry included in battery pack. This includes short circuit protection and cutout switch that opens battery when cell voltage drop below about 2.4 vdc. The series MOSFET switch is about 50 mohms, or almost half of the battery Rs.

As the battery ages and is cycled, the Rs rises. After 150 to 300 recharge cycles the Rs can double from initial new state. For GSM phone with high peak transmit current, and smart phones, the Rs degradation is usually the limiting factor on usuable battery life.

There is no 'reconditioning' procedure for a LiIon battery.