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12V Circuit breakers for auto battery chargers

Discussion in 'Electronic Components' started by [email protected], Jan 9, 2013.

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  1. Guest

    I have a battery charger that is rated at 2, 15, or 100 amps. It's a
    Everstart WM-1510 ma model. (Walmart). I found that Schumacher has an
    identical charger model SE-1510 ma. That says these Everstart chargers
    are made by Schumacher.

    Anyhow, the 12v circuit breaker has died and will not reset. That seems
    to be the most common problem on all chargers.

    My question is this. The Schumacher replacement breaker is rated at 12V
    35A. Since the charger is rated to produce 100A, why are they only
    using a 35A breaker?

    My next question is this:
    I can purchase the identical replacement from for $15.
    While I found a place on ebay that has them for $6 (incl shipping). Of
    course I'll go with the cheaper ones, since this charger is old anyhow,
    so I dont want to sink a lot of money in it. The only problem is that
    the ones on ebay are either 12V 30A, or 12V 40A. (They dont have a
    35A). I'm not sure which would be better. A 30A would protect the
    components more, but would that breaker trip all the time? A 40A is not
    that much higher, and might make the breaker last longer, since these
    things seem prone to failure anyhow.

    Which would be the better choice, the 30A or the 40A?

  2. mike

    mike Guest

    It's a safety issue. The charger isn't rated to put out 100A continuously.
    It's for car starting. If the car starts before the breaker flips,
    you're good to go.
    You also don't want joe sixpack to put 100A into a battery with a shorted
    cell for very long.
    What's your definition of "identical".
    It's a 15A charger, so may not make any practical difference that you'd
    be able to determine from a one-line description on an EBAY page.
  3. Guest

    Direct link from manufacture's website, for parts ordering.
  4. Guest

    Since it's for a battery charger, and not a vehicle, I never thought to
    ask. But I can call and find out....
  5. Guest

    Just to update this, I called the local parts stores. Most said they
    dont have such a thing. One said he could look if I know what make and
    model of car has them. A couple of them referred me to a local
    rebuilder for starters, alternators, and electric motors. I've dealt
    with that place and have never had a good opinion of the place or the
    owner. For example, I took in a starter, and he charged me $90 to
    rebuild it. (I could have bought a rebuilt starter for $60 at the parts
    store). Worse yet, he did not rebuild it properly, because it quit
    working a couple days later, leaving me stranded. He made me remove it
    from the car, tested it, and said there was nothing wrong with it, and
    claimed it was something wrong with my car. I reinstalled it, cleaned
    all cables and terminals. A week later it quit again, once again, he
    made me remove it. When I took it to him, I told him that I wanted a
    completely different starter. He refused, so I phoned my lawyer who
    showed up in his shop and threatened him with legal action. He did give
    me another starter, and it worked. But that cost me lawyer fees on top
    of his ripoff price.

    Anyhow, I did call that asshole today, and he said he can get those
    parts, When I asked the price, he said he would have to contact
    Schumacher and he could order parts for me. But he said that he would
    not order any parts until he tested the transformer and rectifiers in my
    charger. He said that the transformer is probably shot. I told him
    that I already did test everything, and everythin is fine, I just need
    the breaker. I went on to tell him it does charge a battery if I jumper
    across the breaker.

    He clearly told me that unless I'm in his line of business, that I dont
    know how to test it properly, but said that he'll be happy to repair the
    charger for me........ I wont repeat the words I said before I slammed
    down the phone. I can order from Schumacher myself directly. I dont
    need that asshole. But I'd prefer to buy the much cheaper parts on
    ebay. It's just a fairly cheap battery charger. But hey, I fix what I
    can. Money dont grow on trees, and I hate dumping repairable stuff in
    landfills. If I had the part, it would already be fixed. It's a 15
    minute repair.
  6. mike

    mike Guest

    Sounds like the obvious solution.
  7. Sounds like a custom auto breaker. Most Automotive breakers are 15, 20
    or 30A.
    I'd order it thru Schumacher. There might be a reason it's 35A and it
    may have a special thermal curve.

  8. Guest

    Ok, I know they are used in vehicles, but I didn't know what for. Now
    that you told me, I'll have to chack around for RV dealers.
    You got that right.... A battery charger is one of the most simple
    electric devices I can think of repairing, (except for getting the parts
    for some of them). It's just a basic power supply with an amp meter.

    That idiot is not smart, he just thinks he is, and does his best to make
    everyone look like they know nothing. Almost everyone in town hates the
    guy, and they all go to another motor rebuilder in another town about 25
    miles away. That includes the auto parts store right across the street.
    If the parts store cant get the part, they recommend the repair guy 25
    miles away, rather than this idiot who's shop is right across the
    street. Even my lawyer has a few choice words to say when he went there
    about that starter issue.

    The charger does work just fine, except for that breaker. I wired a
    regular 30A plug fuse across the breaker, and charged up my car battery
    before. At least I can use it till I get the part. I only had it charge
    on the 15A setting, so I knew the fuse would hold up, but still be there
    in case of a dead short. Most dead shorts are caused because the clips
    touch each other when we're hooking them up. It never fails! I always
    wondered why they dont put some covering on the clips so only the teeth
    are bare. That would not be rocket science either!
  9. Guest

    Although the local auto parts stores said they did not have them, I went
    to NAPA and asked to see the auto fuses. They had them right there on
    the rack, but not 35A. They had 30A and 40A. I decided to better
    protect the charger, I'd go with the 30A. It's installed, the charger
    works fine on the 2A and 15A settings. I have not yet tried it on the
    100A setting because there are no really discharged batteries at the

    Using your link,
    It looks like this one:

    35A does appear to be an oddball size.

    The one thing I found a little puzzling was the silver and copper
    colored studs. I didn't know there was a polarity to these, but I
    connected it the same way (colors) as the original one.

    I still cant understand how they rate this one at 100A when it only had
    a 35A breaker, I can only assume it's like they rate audio amps. Rather
    than RMS, it's peak. So the charger can put out 100A for a brief amount
    of time when the car is being started. (just a guess).

    Now I'll have to dig out the other 2 or 3 dead battery chargers I got
    laying around, and see if I can fix them. I know for fact that one of
    them needed a breaker, but I could not identify the size and the charger
    is some generic no name brand. I think it's a 10A charger, so I'd guess
    a 10A breaker would work. Since it's winter, now is a good time to fix
    items like this. In warm weather I'm too busy with big projects.

    That's a great idea how to clean up those motor commutators. I've
    rebuilt some motors myself, usually used emory cloth. Motors are not
    that complicated, it's just having the right equipment, particularly of
    the coils need to be rewound. That local idiot got all the equipment
    when another business shut down because the owner retired or died....
    That was before I lived here, but I always hear how nice the original
    owner was, and what an asshole this new guy is.
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