# Charge in the battery after charging for a certain time

1. Sep 15, 2011

### nobrainer612

1. The problem statement, all variables and given/known data

An ideal 9V battery is connected to a resistive divider consisting of a 330 Ohm and a 600Ohm resistor. A 1.5V rechargeable battery in series with a 1.5k Ohm resistor is connected in parallel with the 330 Ohm resistor. The battery has a capacity of 1200mAh and is half charged. How much charge does it hold after 10 hours?

2. Relevant equations

V=R*i

battery charging time = capacity of the battery / charging current power output of the charger:
hr = mAh / mA

AAA – AA – C – D sizes rechargeable batteries:
hours ( charging time ) equals to 12 x Ahr OR 12/100 x mAh ( 12/100 x mAh = hrs )

Power = V*i

3. The attempt at a solution

I tried to find the current going to the 1.5k Ohm dc source. I first combined the R1 and Ri2(internal) as parallel.

1/Req = 1/330 + 1/1500
Req= 270.5

Then I combined R1 to Req since they are in series:

270.5 + 600 = 870.5 Ohm

The the total Req is 870.5 Ohm

Then I tried to find the current passing through the total Req:

V=Ri
i=9V/870.5
i=0.01033

Then I will use the equation:
battery charging time = capacity of the battery / charging current power output of the charger:
= 1200mAH/0.01033
= 116166 .. wow

At this point I am totally confused. Since this is such a large number, I feel like I am doing it wrong.

Any help is appreciated.