If I have a 3V Battery and connect it to a bulb of resistance 12 ohm I should have a current of 0.25A flowing through.
So then if I connect two 3V Batteries in Parallel, should I still have 0.25A in the circuit?
I always thought that batteries in parallel doubled the current in the circuit but I have found it to be different. So what increases. Does the maximum load of the circuit increase? I mean does it mean that this setup could provide up to double the current than that of only one battery?
2007-12-18 06:04:57 · 7 answers · asked by alanjb 1 in Science & Mathematics ➔ Physics
parallel has the same voltage and V=R*I
What you have increased is the potential energy of the circuit, so current will flow longer time than with a single battery.
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2007-12-18 06:09:11 · answer #1 · answered by odu83 7 · 1⤊ 1⤋
by connecting another 3V battery in parallel you are only changing the run time, meaning that you have added additional capacity and will be able to have the light bulb stay on for a longer period of time. None of the number will change, you will still be drawing 0.25A in the circuit.
Batteries are measured by their Amp/hour rating.
Try to find a rechargeble battery and look at the lable.
I have in front of me a rechargeble AA NIMH that states
that is 2000 mA/H This means that this battery will delliver
2000 mAmps for one hour.
Adding another battery of this type in parallel will double this rating.
non-rechargeble batteries like energizer do not offer this info.
So then you may ask what is the difference between an AA cell and a D cell if they are the same voltage.
The D cell has more capacity and thus has a higher amp/hour rating than an AA cell.
2007-12-18 14:20:19 · answer #2 · answered by mixmaster2 3 · 0⤊ 0⤋
I=V/R for you first one you took 3/12 and got .25 A and if you have two batteries in parallel the voltage should be the same because voltage is the same in a parallel circuit.
2007-12-18 14:23:02 · answer #3 · answered by King Arthur 3 · 0⤊ 0⤋
Batteries in parallel double the total capacity, in Ampere-Hours, and doubles the maximum current possible (chemistry/construction limited in batteries).
But your first supposition is correct, E=IR up to the limits of the power supply. Two batteries in parallel are just a larger power supply limit.
2007-12-18 14:11:09 · answer #4 · answered by forhirepen 4 · 0⤊ 0⤋
you need to re-evaluate Ohms Law
Volts/Resistance = I (current)
putting batteries in parallel increases the capacity so the current flows for twice as long
Put batteries in series (aiding) will double the voltage
and double the current
Some batteries have noticeable internal resistance
V/(R_load+R_internal)= actual current
so for 2 batteries in series
2V/(r_load+2R_internal)= actual current
2007-12-18 15:24:01 · answer #5 · answered by Anonymous · 0⤊ 0⤋
By connecting the batteries in parallel you can draw more current at the same voltage as the single battery.
But you will only draw the current needed by the load.
2007-12-18 14:10:15 · answer #6 · answered by Brian K² 6 · 1⤊ 0⤋
Voltage = Current * Resistance.
When you connect two batteries together in parallel, you don't double the output voltage, you double the current capacity.
You have to place the batteries in series to double the voltage.
2007-12-18 14:10:24 · answer #7 · answered by HooKooDooKu 6 · 1⤊ 1⤋