How do I convert amps going out to mah being used

[alpharalpha]

I have a little project involving my son's tablet. The charger input is shot so I'm looking at buying a lion intelligent single cell charger that's 2.5 amps while the tablet's cell is 2400 mah (88wh) I'm wondering how close 2.5 amps will match the tablets power usage, ideally he could keep it plugged in and we won't have the problem with the battery going dead anymore. I have a single cell lifepo4 charger from the same seller and works great for charging my individual lifepo4 eBike cells.) Thanks.

 

[flippy]

mah only tells you the capacity, not the current usage.

how long does the tablet run with the battery? divide that by the ah rating and you have the average current consumption.

by the way, a 4.2v lipo cell with a capacity of 2400mah is only 10.4Wh, not 88Wh.

pushing 2.4 amps into that cell if it's empty will probably destroy it.

 

[alpharalpha]

It's Li Polymer or Li Ion a square tablet cell and it runs from 100% to 0% in about 3 hours. By current consumption does that mean amps?

 

[flippy]

capacity is expressed in Wh or mAh.

if you have a 2400mAh cell and drain it in 3 hours you consume 800mA on average

 

[alpharalpha]

Cool, I found a usb cable that charges 3.7v cells (mostly geared towards those little 'copters) but they plug into a wall wart and charge at around 500ma and they're only like a buck from China, stop charging when full, cheap fix for tablet. I also just found out that the tablet battery lasts a lot longer using headphones instead of the big external speaker so probably will run closer to 500ma now.