After jumpstarting a car, how long should you drive it

[MHDW]

How long should you drive a car after jumstarting it to regain a good charge to the battery before turning off the engine again?

[5000Audi]

just go for a 20 mins drive.. should charge it enough i would say

[Eleanor]

Check the battery with a voltmeter? :dunno: make sure you're getting ~12V

[MHDW]

is it the DRIVING of the vehicle that charges it, or does simply letting it sit parked and running do the exact same thing? Is there a difference when it comes to charging the battery?

[Weapon_R]

That depends on how strong your battery is. I'd try for at least 30-45 minutes before turning it off, but they key to keeping your battery strong is regular driving.

[nobb]

As long as the engine is on, the battery should be charging. 30 mins of the engine on should be enough to charge the battery enough for it to start again. But you should charge the battery with a charger asap because the longer you let the battery sit at a low charge, the more damage is being done. A full charge may take 8 hrs +.

[whiskas]

Originally posted by MHDW
is it the DRIVING of the vehicle that charges it, or does simply letting it sit parked and running do the exact same thing? Is there a difference when it comes to charging the battery?

It'll take forever if you leave it parked. Just take a nomral drive around the city. Try not to run your AC or radio to speed it up.

[Zero102]

The alternator is charging the battery, at idle your alternator is probably making 15-25A (tops), from this consider all the electrics required to run your vehicle. Many vehicles will run from the battery at idle with lights and defrost on for example. Best bet is to do something that will keep the revs up at 2000 or higher. A 20 minute drive around town should suffice.

The only other thing to consider, is whether the battery is frozen or not. A frozen battery will not take a charge unless it is warmed up (although, with this weather, I severely doubt it is frozen).

[Thaco]

yeah basically echoing what these guys say... 20 minutes driving, or an hour + idle.

[GQBalla]

:werd:

[Thaco]

and try to keep off any unnecessary power consuming devices (stereo, lights, heater fan...)

[EK 2.0]

And drive in one lower of a gear than required....that way your revs will stay up...

[4DoorGTZ]

Double the length of your drive if you're sporting an underdrive pulley, and dont even bother thinking it will charge quickly at idle.... from experience.

[MHDW]

Yeah so I drove it for a solid hour yesterday. At a range of speeds, I drove around my community for about half an hour at around 45km/hr and then took a drive down to Okotoks round trip so that was about half an hour. not to mention it idled for about 45 minutes before I did any of that. Pulled it into the garage, turned it off, it started up again no problem.

Went to start it this morning... dead, not completely dead like before, the power doors still worked, and the engine barely tried to start.... but it wouldnt.

Looks like I'll be calling up AMA tonight to test, then likely put in a new battery

[ZorroAMG]

How old is the battery? Anything over 4 years or so if drained to dead, replace.

[Zero102]

If it was run entirely flat individual cells within the battery can reverse, making it basically useless. Hopefully this hasn't happened.
Remove it from the car, put it on a 2-5A charger for 2 days straight, let it sit for an hour or two, then test the terminal voltage. Less than 12.6-12.8V and the battery is junk.

Was the battery flat during the cold spell? If so it likely froze inside and can be badly damaged as a result.

[chkolny541]

Originally posted by Thaco
and try to keep off any unnecessary power consuming devices (stereo, lights, heater fan...)

:werd: :werd: this^^

[MHDW]

Originally posted by Zero102
If it was run entirely flat individual cells within the battery can reverse, making it basically useless. Hopefully this hasn't happened.
Remove it from the car, put it on a 2-5A charger for 2 days straight, let it sit for an hour or two, then test the terminal voltage. Less than 12.6-12.8V and the battery is junk.

Was the battery flat during the cold spell? If so it likely froze inside and can be badly damaged as a result.

It was 100% dead flat during the cold spell yes... totaly 100 % dead woudlnt even unlock the doors.