There are a few variables to take into account here. The discharged state of the battery and the current produced by the battery charger on the slow charge position are two of the most important. The amp/hour size of the battery is another governing factor.
2 hours i heard on youtube
I charge my battery 4 hours and 30 minutes
You need to have a 7.2 or higher battery charger
Yes it has a 2amp trickle charge
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).
If it is an automatic charger let it charge until the charger shuts off.
A trickle charger is a car battery charger that is designed to be left on a car for very long periods of time to re-charge that car battery by slowly adding charge to the battery.
You do not charge a 7.2 volt battery with a 9.6 volt charger period unless you want to ruin the battery. You charge it with a 7.2 volt charger.
I doubt the charger is putting out 30 Amps on a slow charge. need more info on battery and charger.
With a charger specifically designed to charge this battery.
As long as both batteries are the same voltage, you can jump start with the battery. If you want to charge the battery then use a battery charger.
As long as it is a 12 volt battery you can if you set the charger on low.
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.
Depends on the amperage of the charger. A 10 amp charger will charge it in about 1 hour.
A very, very, long time with direct sunlight. Charge your battery with a battery charger
Whether it says it will or not, battery chargers will charge any battery, as long as they are for the same voltage. The charger puts out a set voltage, it doesn't know whether the battery is Energizer or not.
This depends on what kind or charger are you asking about and what kind of battery are you charging. My Phone charger takes two hours to charge my phone.