308 Battery blowout

Discussion in 'Technical Q&A' started by fastaone, Mar 28, 2004.

  1. fastaone

    fastaone Karting

    Jan 9, 2004
    Long Island
    Full Name:
    Peter F
    Hello Ferraristi:
    Today I was driving along the highway with my 83 308 QV . I was going 70MPH. After about 20 miles I started to smell a funky odor, I thought was coming from outside, Then I heard a BANG!! like I got a tire blowout, I stop on the side look to see but everything looked OK, until I saw some liquid dripping from the front part of the car, so I took the spare tire out and the battery cover to find the battery blown on one side, I mean BLOWN.
    I disconnected the (negative) on the battery, while the car was running and I slowly made it home.
    Here is my question:
    What caused the battery to blow?
    My guess is the alternator; the battery is one year old.
    If it's the alternator should I get a rebuild or new
    Thanks in advance
  2. To remove this ad click here.

  3. yelcab

    yelcab F1 World Champ

    Nov 29, 2001
    San Carlos, CA
    Full Name:
    Mitchell Le
    My guess is the voltage regulator has died, causing the alternator voltage to charge the battery directly and causing way too much gas build up inside the battery until ... bang.
  4. Dr_ferrari

    Dr_ferrari Formula 3
    Professional Ferrari Technician Consultant

    Nov 2, 2003
    Pocono Sportscar
    Full Name:
    Jim McGee
    Most probably the alternator was overcharging the battery. Also, The battery itself could have been bad with an internal short causing the problem.
    wash the area down with a baking soda and water solution to neutrialize the acid, remove the battery, WASH AREA AGAIN WITH SOLUTION AND RINSE WELL.
    Install new battery and check the charge rate. If battery voltage when charging exceeds 14.5, then I would say the alternator voltage regulator is a fault.
    Since the regulator is in the alternator, the unit should be replaced or rebuilt.

    Make sure to wear rubber gloves when cleaning and removing that blown up battery.To ensure you don`t spill any acid on the body of the car when removing, get a battery sized bucket/bin to put the battery in while under the bonnet.

    best regards, jim
  5. Mike328

    Mike328 F1 Rookie
    Rossa Subscribed

    Oct 19, 2002
    Boulder, CO
    Full Name:
    Had a battery blowout last year. Interstate battery. One of the two water-level inspection/fill covers had popped right off!

    As it happened, the voltage regulator inside my alternator failed, and the battery was getting charged with a hefty 17+ volts, most definitely outside of specification.

    If this is the case for you, then an alternator rebuild that includes a voltage regulator (VR) replacement (and upgrade the alternator max current output while you're at it, search the archives for more info) should solve the problem... Then get a new battery (many use Optima Red Tops, good if you use your car regularly).

  6. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    Groton, MA
    Full Name:
    Verell Boaen
    If the charging voltage is too high(~15 or more volts)
    , then you probably only need the regulator/brush ass'y.

    The voltage regulator/brush ass'y used on the 308 QV BOSCH alternators can be replaced w/o rebuilding the alternator. It can be done w/o completely removing the alternator from the car.

    The regulator/brush ass'y runs about $50.
    Any BOSCH rebuilder can get you one.

    There are also exact replacement aftermarket ones. I can get one thru Unobtainium Supply. Contact me if you're interested.
  7. To remove this ad click here.

Share This Page