As long as the ATV is wired 12 volt, not 6.
Yes you can. The battery supplies only as much current (amps) as the lamp draws when connected to 6 volts. The "12 amp" battery won't supply any more current when the lamp is shining than the "6 amp" battery did, but it'll last twice as long between charges.
The 12 amp hour battery will last longer under the same load as a 10 amp hour battery. For example if you had a load drawing 2 amps, the 12 Ahr battery would last 6 hours and the 10 Ahr would last 5 hours under ideal conditions.
Around 4 hours on a dead battery.
To charge a 12-volt battery, you need somewhat MORE than 12 volt. The 500 ma and the 6 amp are unrelated: battery capacity is often expressed in ampere-HOURS, which is not the same as amperes.
A .6 amp charger is a trickle charger. It would take days to charge a dead 12 volt battery with this charger. You need a 10 amp charger which will charge it in a couple of hours.
for the relay switch 6volts, for the battery... dunno- mine's a 250 and uses an ATV battery.. I think they're 12 volts.
Ah is amp hours. It describes the capacity of the battery. A bit like the size of a fuel tank. The 12 Ah battery can deliver 12 amps for one hour, 24 amps for 1/2 hour or 6 amps for two hours. Or any other combination of time x amps that makes 12. The 35 amp hour battery is almost three times the capacity of the 12 amp hour battery.
No, you would be applying 24 volts to the 12 volt battery.
No because an ATV battery only can take 2 amps and a car charger pushes out 6 to ten But you can use a float charger there perfectly safe. it depends on your charger. most chargers have several amp settings to choose from. mine has settings for 2, 10, 25, 40, and 200 amps for jump starting. as long as you make sure the volts, 6 or 12, are right it will charge it.
You can charge a 12 volt battery with a 6 AMP charger. The amount of amps put out by the charger is actually the rate which the power flows out from the charger, not the amount of volts it will charge. Volts and Amps are two different things. You can't charge up a 12 volt battery all the way, using a 6 volt charger. You can charge a 12 volt battery with a 12 volt charger rated at '6 amps'. It will charge the battery faster than a 2 amp charger will, but it will take longer than using a 12 amp charger. You probably don't want to use anything higher than a 12-16 amp charger for charging a 12 volt battery. Some chargers are equipped with a 60amp boost charge that is used for starting the vehicle, without having much of a charge in the battery. You DO NOT want to attempt charging a battery with it set to a 60amp boost charge. That is for starting vehicles only and could damage your battery. Keep in mind that the lower the amps are, that you use to charge the battery (1-2amps), will result in the charge lasting longer without recharging it, than if it was charged up at a higher setting (12-16amps).
12 V - probably, although ther are exceptions. 6 Amps - ?? 6 Ams would be a measure of a current draw, and a battery is a current source. A car battery might have a capacity of 60 amp hours or thereabouts.