Charging a battery with an alternator is not the best idea if you care about the alternator, some are expensive.

Removing the battery from the mix to see if the alternator is good may have been ok for cars of yesteryear - cars and their elctronics are much more complex now and it's not a great idea.

so I hear...

 

One of the alternator's jobs is to recharge the battery while the car is running. There's no way it can be bad to charge the battery with the alternator... it's made to work that way. There would be problems if it werent charging it.

 

The alternators jobs is to charge the battery only from the amount of voltage used during starting. Not to charge completely dead battery! Doing so can cause a surge and damage electrical components including the alternator and battery.

 

try to keep your battery charged via a trickle charger or whatever. Try not to let it get discharged in the first place. But if it does (which can damage a battery anyway) charge it before you put it in your car.

it's not the job of the alternator to be bringing batteries back from the brink of death

 

guess i didnt read the post all the way through, I just assumed that you were saying that in general it's bad for alternators to charge batteries hah. sorry. Yes, a alternator that's trying to charge a dead battery is a waste, you'll lose a little power, nothing too bad atleast, car should be driveable still. Startable is a different case heh.

 

I am very vague sometimes, to a fault.

Happy Holidays!