Mike, I’m assuming the solar panel in question is wired for 12 volt battery charging, which means it actually peaks out at 18 volts if the circuit is open. Panels are rated in watts, which is found by multiplying the panels open circuit voltage by it’s short circuit current, or amps. A 100 amp panel wired for 18 volts would have a short circuit current of 5.5 amps. My guess is the question is using a 55 amp hour battery because it is exactly 10 times the amp rating on such a panel.
You might see the answer already, but I’ll explain further anyway. If a battery holds 55 amp hours, that means you can start out fully charged, and draw 55 amps out for an hour before it is dead. Or you could draw out 1 amp for 55 hours, and end up at the same place. So if the panel can feed in 5.5 amps for 10 hours, then it would replace 5.5 X 10 = 55 amp hours.
In the real world, the panel would actually put out a bit less than 5.5 amps, since it would not actually be at short circuit amps with a 12 volt battery in front of it. The battery is not 100% efficient, so each 10 amp hours you feed in might yield 8 amp hours of storage, and so on. But I’m guessing the question you are trying to answer is theoretical, so they are probably looking for 10 hours, in direct sunlight that is. Good luck, and take care, Rudydoo
55 amps at 12volts is 660 watts so 6.6 hours in theory but no battery can be charged at that rate, I don’t know why they keep setting questions that are totally removed from reality
Mike, I’m assuming the solar panel in question is wired for 12 volt battery charging, which means it actually peaks out at 18 volts if the circuit is open. Panels are rated in watts, which is found by multiplying the panels open circuit voltage by it’s short circuit current, or amps. A 100 amp panel wired for 18 volts would have a short circuit current of 5.5 amps. My guess is the question is using a 55 amp hour battery because it is exactly 10 times the amp rating on such a panel.
You might see the answer already, but I’ll explain further anyway. If a battery holds 55 amp hours, that means you can start out fully charged, and draw 55 amps out for an hour before it is dead. Or you could draw out 1 amp for 55 hours, and end up at the same place. So if the panel can feed in 5.5 amps for 10 hours, then it would replace 5.5 X 10 = 55 amp hours.
In the real world, the panel would actually put out a bit less than 5.5 amps, since it would not actually be at short circuit amps with a 12 volt battery in front of it. The battery is not 100% efficient, so each 10 amp hours you feed in might yield 8 amp hours of storage, and so on. But I’m guessing the question you are trying to answer is theoretical, so they are probably looking for 10 hours, in direct sunlight that is. Good luck, and take care, Rudydoo
Watt = Volts * Amperes. I’m sure you can do the rest.
55 amps at 12volts is 660 watts so 6.6 hours in theory but no battery can be charged at that rate, I don’t know why they keep setting questions that are totally removed from reality
power (watts) = e squared times current
a 12 v battery supplying 55 amps needs 144 times 55 = 7920 watts
so 79.2 hours