charging vs "charging" the battery

Question for the wise....

normally, when i I've accidently let something drain my battery down, i've just jumped my car, and made sure i drove for an hour or so, to get the battery "charged". I've heard people here on the forums say that doing that stresses the alternator, because it forces the alternator to work harder until the battery is back to full charge. Since i have a 540, with the water cooled alternator, i want to treat it well. However, the Alternator is rated at 150 amps. this seems like it'd be able to take quite a load, and "charging" the battery seems like it should be the responsibility of the alternator.

So, should i charge the battery up with a trickle charger overnight, after a run-down? does this really "lighten the load" on the alternator? I've never had to do this with any other car, why with the BMW?

Also, is there any "high output" alternator alternatives? In my Grand Marquis, i can get a 200amp alternator that's for a police-package Crown Vic. I'd love an option like this for the BMW. That way, i'd feel fine about adding a winch (for all those times i'm stuck on a hill in the snow!)

you'll be fine, ive killed my battery countless times, jumped it, drove for a little bit and called it a day. been doing that for 4 years now and i still dont have issues. im sure bmw wouldnt put an alternator in there that cant handle something like that.

You are OK, don't worry.

very good. thanks!

Bear in mind that the job of the alt is to run the car after the engine is started; it supplies all the current required. It also replaces the energy that was used to start the car.

If you do this frequently, it will stress the alt, as well as the battery. A dead battery s/b brought back to life slowly, charging at about 10% of its ampere-hour rating.

Originally Posted by edjack

Bear in mind that the job of the alt is to run the car after the engine is started; it supplies all the current required. It also replaces the energy that was used to start the car.

If you do this frequently, it will stress the alt, as well as the battery. A dead battery s/b brought back to life slowly, charging at about 10% of its ampere-hour rating.

Correctomundo....One other overlooked aspect is that any battery (especially an older one) that has been left in a discharged state for any length of time is probably incapable of taking and holding a full charge, which can lead to all sorts of gremlins popping up, as well as the possibility of outright failure. Better to replace it now, before it leaves you stranded at 2 a.m.

1+,

Car battery is not like cell phone battery (I think battery cell phone needs to be d/c completely once ina w hile).
Car battery, after a few cycles of complete d/c, is basically a goner. It holds charge very poorly.

Too bad car maker does not make the hand crank any longer, otherwise, it may be a useful feature for the worst case scenario getting stuck somewhere with dead battery:

i vote for lithium polymer car batteries.

http://www.coloradoautoconnection.co...ries_aev_3.asp

Originally Posted by jbrovage

i vote for lithium polymer car batteries.

http://www.coloradoautoconnection.co...ries_aev_3.asp

The battery featured in the link is for a completely different application (i.e., powering an electric motor, with a constant output, demand & load). It doesn`t have a CCA rating, which would be the critical spec for use with a high-compression IC engine....

Originally Posted by cn90

1+,

Too bad car maker does not make the hand crank any longer, otherwise, it may be a useful feature for the worst case scenario getting stuck somewhere with dead battery:

]

I`ve often thought the same thing....a "port" through the grille, where you insert a long splined shaft which interfaces with a gear-reduction box, which in turn spins the crankshaft pulley....your 19Volt, 1/2-inch drive portable drill would provide the power. Of course, you`d probably need a compression-release feature of some design....

Originally Posted by Fast Bob

The battery featured in the link is for a completely different application (i.e., powering an electric motor, with a constant output, demand & load). It doesn`t have a CCA rating, which would be the critical spec for use with a high-compression IC engine....

I figured if you put enough together in parallel, you'd get enough CCA. if each one is 160amps, maybe 5 of them would do it?

Plus, they are designed to be fully discharged occasionally. So no worries about running your radio all day while you wash/wax your car...

Offtopic: Cellphones with Lithium-Ion or Lithium Polymer batteries should not be run down.