Charge in the battery after charging for a certain timeby nobrainer612 Tags: battery, battery capacity, charge, charging, ideal battery 

#1
Sep1511, 11:11 AM

P: 26

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. 


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