Connecting a jumper battery or power axillary power source only makes additional current available, if the starting circuit needs it. If the batteries are connected properly [in parallel] then this procedure increases the cranking Amps available and the voltage remains the same.
If you need to jump start the car then the battery may be fully charged but it is defective and needs replacing. A full charged battery will read 12.6 volts at the posts with the engine not running. 12 volts indicates the battery is only 25% charged.
Do you wish to jump a car with a deep-cycle battery, or do you wish to charge another battery using the deep-cycle battery?
In most cases a new battery will be charged enough to start the vehicle
If you can jump start the car then the battery is not fine. Remove the battery cables and thoroughly clean them. If it still will not start check the voltage at the battery with the engine off. You should get 12.6 volts if the battery is fully charged. 12.4 it is 75%, 12.2 it is 50%, and 12.0 it is 25% charged. I would bet your battery is defective.
Is the battery fully charged? Try jump-starting it.
You should never drive a car around for long after jump starting a dead battery. This puts an enormous strain on the alternator. Alternators are designed to keep a good battery charged, not to charge a dead battery. You can easily burn out a diode in the alternator. Jump start the engine and drive it somewhere and connect a battery charger to the battery and charge it fully.
It isn't adviseable to use a battery charger to jump start a car unless the charger has a jump selection on it. Most newer models do have this function. The best thing to do, whether your charger has the jump function or not, is to take out the battery and put it on a trickle charge - usually about 2 amps, until the battery itself is fully charged.
That depends on the battery, and the charger. my charger has different settings for higher amps to give a faster charge or jump. A fully charged battery will show 12.6 volts. The charger will read it's maximum amperage if the battery is totally discharged. A fully charged battery will read 12.6 volts with a digital DC volt meter. If it reads 12 volts it has less than 25% charge.
Check ignition relay. Jump the battery directly to the starter and see if the starter is any good.
I am assuming you mean with the auto engine running. Yes, that is possible but you are putting a strain on the alternator of the car. An alternator is not designed to charge a dead battery. It is designed to keep a charged battery fully charged. as long as the ATV battery is the same voltage as the car battery, usually 12 volts, you can charge it, or jump start the atv and let it charge the battery itself.
Yes.
Typically a charger is not meant ot "jump start" and engine. It provides a slow, regulated charge to the battery. A car battery or fully charged battery will typically provide enough pwoer to jump start your tractor. I recommend charging your battery for a number of hours (or overnight) till completely recharged. If the tractor will no start without a jump, your battery may be in need of replacement.