How long does it take to charge a battery?

Discussion in 'The Garage' started by IHateMyJob2004, Dec 5, 2010.

  1. IHateMyJob2004

    Joined:
    Sep 29, 2004
    Messages:
    17,699
    Likes Received:
    1
    The battery on my truck is almost dead. I want to give it a full charge.

    I have the charger set to 12 volts, 10 amps.

    It's been there for 3 hours and the "charge complete" light has not turned on.

    I have been reading and I keep seeing articles that say 30 minutes to 2 hours for a full charge.

    FWIW: 2003 Chevy 1500. battery is about 2 years old.
     
  2. exdeath

    exdeath Lifer

    Joined:
    Jan 29, 2004
    Messages:
    13,643
    Likes Received:
    0
    I'd charge it on 10 amps for a couple hours, then set it to 2 amp over night.

    It takes a while when it's fully discharged.
     
  3. The Stigenator

    Joined:
    Oct 9, 1999
    Messages:
    15,185
    Likes Received:
    1
    At 10 amp/hr it will take about overnight or more to fully charge depending on the amp capacity on the battery and how drained it is. I'd leave it for at least over night. Recharge tomorrow night again. Last time I recharged my battery I left it over the weekend. Remember to ventilate so you dong store
     
  4. The Stigenator

    Joined:
    Oct 9, 1999
    Messages:
    15,185
    Likes Received:
    1
    Oops I meant don't store hydrogen. Careful on that. Ventilate.
     
  5. Zenmervolt

    Zenmervolt Supermoderator<br>The Garage<br>Elite member

    Joined:
    Oct 22, 2000
    Messages:
    24,522
    Likes Received:
    0
    Divide the battery's capacity in amp-hours by the charging rate.

    A typical automotive battery will likely have between 45 and 80 amp-hours of total capacity. If it's completely discharged, that would mean between 4.5 and 8 hours for a 10 amp charger to bring it back. In reality if the battery is still starting the car or truck then you probably have at least 50&#37; charge and likely more.

    Basically the answer is, unfortunately, "it depends".

    ZV
     
  6. T2urtle

    T2urtle Diamond Member

    Joined:
    Oct 18, 2004
    Messages:
    3,401
    Likes Received:
    0
    i always left it on lowest trickle if its off the car overnight and about 30 minutes before i install it back into the car i put it on "fast start" i think thats like 20-50AMPS. i have a 3 setting one. 2/10/ XX AMP.

    normally works for me. I guess 8 hours at 10AMP works. Anyone leave it at autozone or something i heard they charge battery overnight as well.
     
  7. Meghan54

    Meghan54 Diamond Member

    Joined:
    Oct 18, 2009
    Messages:
    6,665
    Likes Received:
    33

    So very true. Of course, part of "it depends" is if all the cells in the battery are good and will accept a charge. Nothing more frustrating than spending time trying to charge a battery only to find out that one cell is bad. Fortunately, better chargers will "diagnose" such a problem, but still takes time.
     
  8. Fallingwater

    Fallingwater Member

    Joined:
    Nov 28, 2010
    Messages:
    160
    Likes Received:
    0
    A fast "just get the damn engine started" charge is achievable in as low as 30 minutes, if you've got a beefy enough charger. A slower proper charge is an overnight process. A desulfating recharge, where you hook up a desulfator and a charger in parallel to restore to partially-good condition an otherwise dead battery, can take whole days.
     
  9. IHateMyJob2004

    Joined:
    Sep 29, 2004
    Messages:
    17,699
    Likes Received:
    1
    I charged it overnight. What I did not say is that I think the alternator was dead.

    So I drove it to the repair place by work after a 10 hour charging session. So, it lasted 30 minutes on the road. When I got to the repair shop, it stalled. Unreal. It still had enough juice left to re-start the truck easily so I could get it into a parking spot.

    Thanks all!