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.
As long as the battery is fully charged it will start no matter the condition of the alternator. Eventually the battery will run down if the alternator is not keeping it charged.
It will start if there is enough charge in the battery to turn the engine over. However if the alternator is weak then the battery will not be charged fully.
Does it turn over? Does it have spark? Does it have fuel?
Fresh fully charged battery and fresh gasoline
Low/bad battery, bad battery connection. If the battery isn't getting fully charged you might not be able to start. If it isn't getting charged, check the alternator.
YOU HAVE TO TURN IT ON Actually, I learned this past week that if it is a gel type battery, you can get a false positive on the battery, so it looks like it is fully charged but actually is not. You can take the battery to your dealer to see if he can charge it or you need a new one.
In most cases a new battery will be charged enough to start the vehicle
It could be a number of things. First check that the battery is fully charged.
Be sure the battery is fully charged before you start. A fully charged battery should read 12.68 Volts. If the battery is very low when you check the alternator output it will not give you an accurate reading.
The battery will run down and he engine will stop. You will not be able to start the engine. The alternator keeps the battery fully charged.
Usually 11.5v is enough to start most cars. A fully charged battery is 12.6v
DOES the engine turn over? if yes is there spark at the plugs? is there fuel to the injectors?
Yes, the battery starts the engine, and as long as the battery is fully charged the engine will start. The battery will loose it's charge if the alternator is defective and not replenishing the charge of the battery but the alternator has nothing to do with starting the engine.
is your battery in good condition and fully charged? is your starter good?
Most likely the starter solenoid needs replacement
Make absolutely sure that the battery is fully charged. If the battery is dis-charged, it will not supply enough voltage to the coil, especially while cranking.
If the alternator is bad the car will still start. You just need a fully charged battery. Once running then you can check the charge rate from the battery with a volt meter.
It will start if the battery is fully charged. But you will soon (in less than an hour in most cases) end up with a dead battery requiring you to have the vehicle hauled to the garage anyways.
A lot of modern computerized cars won't start on less than a fully charged battery. Some may even require a reset.
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 new battery well charged? Is the starter bendix stuck? Is the starter ring stuck?
bad solenoid...will usually click up a storm when you turn on the ignition.
My 2005 Honda Forman rancher ATV dies unable to start or shift back to neutral when checking battery still says it is fully charged. Could it be a regulator problem?
Corrosion on the wires, bad starter or starter solenoid, worn flywheel or flexplate, many things. Even just corroded battery terminals could cause no start.