Faulty car battery charger

Discussion in 'UK DIY' started by wb, Feb 15, 2005.

  1. wb

    wb Guest

    My battery charger seems to be faulty - cutting out as soon as it is
    plugged in, with a flash coming regularly every couple of seconds
    (from a fuse-like bulb located on top of the coil (cover off)).
    It's a good enough charger when it's working, with boost/fast start as
    well as trickle; it also has an automatic cut-out to prevent
    over-charging. With the cover off, there does not seem to be any
    obvious short.
    Any ideas?
    wb, Feb 15, 2005
    #1
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  2. wb

    wb Guest

    On Tue, 15 Feb 2005 01:40:12 -0000, "Paul King"
    <> wrote:

    >wb wrote:
    >> My battery charger seems to be faulty - cutting out as soon as it is
    >> plugged in, with a flash coming regularly every couple of seconds
    >> (from a fuse-like bulb located on top of the coil (cover off)).
    >> It's a good enough charger when it's working, with boost/fast start as
    >> well as trickle; it also has an automatic cut-out to prevent
    >> over-charging. With the cover off, there does not seem to be any
    >> obvious short.
    >> Any ideas?

    >
    >Long distance diagnosis of this sort is impossible without greater
    >information ... What make/model is the charger? When was the last time you
    >used it and "knew" it to work? Why do you have the top off and what leads
    >you to think its faulty? Is not the battery screwed perhaps, leading to the
    >charger shutting down due to overcurrent?



    It's a "GUNSON's Rapid Start Heavy Duty Starting Charger suitable for
    all 12v Lead/Acid batteries
    Start: 47A RMS 30A DC @ 9v (10-15 secs)
    Boost: 26A RMS 17A DC @ 12v (10 minutes)
    Fast: 15A RMS 10A DC @ 12v (continuous)

    Recommended minimum battery capacity: 30Ah.
    Full overload protection,
    Reverse polarity protection.
    Thermal cut-out protection."

    I last used it at Christmas to quick start my car battery; it worked
    fine. My son put it on an old (12v) battery he had been using for an
    electric fence for his chickens (does not need full 12 volts). He
    noted it flashing a making a pulsing clicking sound. I then tried it
    on a working forklift battery with the same result.
    I took the top off to check for any obvious shorting or dampness. I
    have never noticed it flashing prior to this. Needless to say, I
    can't find the instructions anywhere.
    wb, Feb 15, 2005
    #2
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  3. wb

    Guest

    wb wrote:
    > On Tue, 15 Feb 2005 01:40:12 -0000, "Paul King"
    > <> wrote:
    >
    > >wb wrote:
    > >> My battery charger seems to be faulty - cutting out as soon as it

    is
    > >> plugged in, with a flash coming regularly every couple of seconds
    > >> (from a fuse-like bulb located on top of the coil (cover off)).
    > >> It's a good enough charger when it's working, with boost/fast

    start as
    > >> well as trickle; it also has an automatic cut-out to prevent
    > >> over-charging. With the cover off, there does not seem to be any
    > >> obvious short.
    > >> Any ideas?

    > >
    > >Long distance diagnosis of this sort is impossible without greater
    > >information ... What make/model is the charger? When was the last

    time you
    > >used it and "knew" it to work? Why do you have the top off and what

    leads
    > >you to think its faulty? Is not the battery screwed perhaps, leading

    to the
    > >charger shutting down due to overcurrent?

    >
    >
    > It's a "GUNSON's Rapid Start Heavy Duty Starting Charger suitable

    for
    > all 12v Lead/Acid batteries
    > Start: 47A RMS 30A DC @ 9v (10-15 secs)
    > Boost: 26A RMS 17A DC @ 12v (10 minutes)
    > Fast: 15A RMS 10A DC @ 12v (continuous)
    >
    > Recommended minimum battery capacity: 30Ah.
    > Full overload protection,
    > Reverse polarity protection.
    > Thermal cut-out protection."
    >
    > I last used it at Christmas to quick start my car battery; it worked
    > fine. My son put it on an old (12v) battery he had been using for an
    > electric fence for his chickens (does not need full 12 volts). He
    > noted it flashing a making a pulsing clicking sound. I then tried it
    > on a working forklift battery with the same result.
    > I took the top off to check for any obvious shorting or dampness. I
    > have never noticed it flashing prior to this. Needless to say, I
    > can't find the instructions anywhere.


    post the circuit diagram for us, get ready with the multimeter, and
    we'll see if we can take you through it.

    NT
    , Feb 15, 2005
    #3
  4. wb

    Pete Cross Guest

    I repaired one of these last month ( friend who lives on a barge ! )

    Inside at the front is a printed circuit board with a large relay underneath
    it, yes ? towards one corner ( same side as the start/boost switch towards
    rear of pcb ) there is a small 10uF 25v electrolytic capacitor which will be
    dried up and open circuit. This causes the relay to quickly pulse on/off
    instead of coming on until the battery reaches a high enough voltage. Also
    the green 12v bulb on the front panel which is lit all the time a battery is
    connected had gone ( spare xmas tree bulb fitted fine ).

    --
    Pete Cross


    > wb wrote:
    > > On Tue, 15 Feb 2005 01:40:12 -0000, "Paul King"
    > > <> wrote:
    > >
    > > >wb wrote:
    > > >> My battery charger seems to be faulty - cutting out as soon as it

    > is
    > > >> plugged in, with a flash coming regularly every couple of seconds
    > > >> (from a fuse-like bulb located on top of the coil (cover off)).
    > > >> It's a good enough charger when it's working, with boost/fast

    > start as
    > > >> well as trickle; it also has an automatic cut-out to prevent
    > > >> over-charging. With the cover off, there does not seem to be any
    > > >> obvious short.
    > > >> Any ideas?
    > > >
    > > >Long distance diagnosis of this sort is impossible without greater
    > > >information ... What make/model is the charger? When was the last

    > time you
    > > >used it and "knew" it to work? Why do you have the top off and what

    > leads
    > > >you to think its faulty? Is not the battery screwed perhaps, leading

    > to the
    > > >charger shutting down due to overcurrent?

    > >
    > >
    > > It's a "GUNSON's Rapid Start Heavy Duty Starting Charger suitable

    > for
    > > all 12v Lead/Acid batteries
    > > Start: 47A RMS 30A DC @ 9v (10-15 secs)
    > > Boost: 26A RMS 17A DC @ 12v (10 minutes)
    > > Fast: 15A RMS 10A DC @ 12v (continuous)
    > >
    > > Recommended minimum battery capacity: 30Ah.
    > > Full overload protection,
    > > Reverse polarity protection.
    > > Thermal cut-out protection."
    > >
    > > I last used it at Christmas to quick start my car battery; it worked
    > > fine. My son put it on an old (12v) battery he had been using for an
    > > electric fence for his chickens (does not need full 12 volts). He
    > > noted it flashing a making a pulsing clicking sound. I then tried it
    > > on a working forklift battery with the same result.
    > > I took the top off to check for any obvious shorting or dampness. I
    > > have never noticed it flashing prior to this. Needless to say, I
    > > can't find the instructions anywhere.

    >
    > post the circuit diagram for us, get ready with the multimeter, and
    > we'll see if we can take you through it.
    >
    > NT
    >
    Pete Cross, Feb 15, 2005
    #4
  5. wb

    wb Guest

    On 15 Feb 2005 04:59:51 -0800, wrote:

    >wb wrote:
    >> On Tue, 15 Feb 2005 01:40:12 -0000, "Paul King"
    >> <> wrote:
    >>
    >> >wb wrote:
    >> >> My battery charger seems to be faulty - cutting out as soon as it

    >is
    >> >> plugged in, with a flash coming regularly every couple of seconds
    >> >> (from a fuse-like bulb located on top of the coil (cover off)).


    >
    >post the circuit diagram for us, get ready with the multimeter, and
    >we'll see if we can take you through it.
    >
    >NT



    Sorry, I've no circuit diagram but I've posted some photos here:

    http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de

    Hope this helps.
    I think my charger is an older one than Pete suggests

    Regards
    wb, Feb 16, 2005
    #5
  6. wb

    Guest

    wb wrote:
    > On 15 Feb 2005 04:59:51 -0800, wrote:
    > >> <> wrote:


    > >> >> My battery charger seems to be faulty - cutting out as soon as

    it
    > >is
    > >> >> plugged in, with a flash coming regularly every couple of

    seconds
    > >> >> (from a fuse-like bulb located on top of the coil (cover off)).



    > >post the circuit diagram for us, get ready with the multimeter, and
    > >we'll see if we can take you through it.



    > Sorry, I've no circuit diagram but I've posted some photos here:
    >
    > http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    >
    > Hope this helps.



    Certainly brought a smile to my face
    , Feb 16, 2005
    #6
  7. wb

    wb Guest


    >
    >> >post the circuit diagram for us, get ready with the multimeter, and
    >> >we'll see if we can take you through it.

    >
    >
    >> Sorry, I've no circuit diagram but I've posted some photos here:
    >>
    >> http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    >>
    >> Hope this helps.

    >
    >
    >Certainly brought a smile to my face


    Glad to hear it NT, which is more than can be said for my son's
    chickens - they got a visit from the fox last night - left nothing but
    a few feathers!
    I'd be grateful for any suggestions (about the charger, not the fox!).
    I have the technology (ie multimeter) but not the knowledge
    (self-evident!).

    Regards
    wb, Feb 16, 2005
    #7
  8. wb

    Guest

    wb wrote:

    > >> >post the circuit diagram for us, get ready with the multimeter,

    and
    > >> >we'll see if we can take you through it.

    > >
    > >
    > >> Sorry, I've no circuit diagram but I've posted some photos here:
    > >>
    > >> http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    > >>
    > >> Hope this helps.

    > >
    > >
    > >Certainly brought a smile to my face


    > I'd be grateful for any suggestions (about the charger, not the

    fox!).
    > I have the technology (ie multimeter) but not the knowledge
    > (self-evident!).



    Well I made it, but I guess I wasnt clear enough.
    1. your charger is faulty
    2. the only way youre giong to fix it is with a circuit diagram and
    some electronics expertise.
    3. You can borrow the latter off the net, but you'll have to come up
    with the circuit diagram.

    Otherwise youre outta luck.

    NT
    , Feb 16, 2005
    #8
  9. wb

    Pete C Guest

    On Wed, 16 Feb 2005 13:47:18 +0000, wb <>
    wrote:

    >
    >>
    >>> >post the circuit diagram for us, get ready with the multimeter, and
    >>> >we'll see if we can take you through it.

    >>
    >>
    >>> Sorry, I've no circuit diagram but I've posted some photos here:
    >>>
    >>> http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    >>>
    >>> Hope this helps.

    >>
    >>
    >>Certainly brought a smile to my face

    >
    >Glad to hear it NT, which is more than can be said for my son's
    >chickens - they got a visit from the fox last night - left nothing but
    >a few feathers!
    >I'd be grateful for any suggestions (about the charger, not the fox!).
    >I have the technology (ie multimeter) but not the knowledge
    >(self-evident!).
    >
    >Regards


    Hi,

    Does it cut out even when no battery is connected?

    If so switch off and try disconnecting one of the wires from the
    secondary (non mains) side of the transformer that go to the black box
    on the heatsink.

    Then does it still cut out?

    If so it's likely to be a short in the transformer which is probably
    not worth replacing, if not it's likely to be the black box (bridge
    rectifier) on the heatsink which should be fairly cheap and easy to
    replace.

    cheers,
    Pete.
    Pete C, Feb 18, 2005
    #9
  10. wb

    wb Guest

    On Fri, 18 Feb 2005 14:23:52 +0000, Pete C <>
    wrote:

    >On Wed, 16 Feb 2005 13:47:18 +0000, wb <>
    >wrote:
    >>>
    >>>> Sorry, I've no circuit diagram but I've posted some photos here:
    >>>>
    >>>> http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    >>>>


    snip

    >
    >Does it cut out even when no battery is connected?
    >
    >If so switch off and try disconnecting one of the wires from the
    >secondary (non mains) side of the transformer that go to the black box
    >on the heatsink.
    >
    >Then does it still cut out?
    >
    >If so it's likely to be a short in the transformer which is probably
    >not worth replacing, if not it's likely to be the black box (bridge
    >rectifier) on the heatsink which should be fairly cheap and easy to
    >replace.
    >
    >cheers,
    >Pete.



    Thanks Pete,

    It does cut out when no battery is connected but doesn't when I
    disconnect either wire going to the black box from the transformer.
    So, hopefully, a new bridge rectifier will solve my problem. Is this
    the sort of thing I can get at Maplins - I've had a look but none has
    the same markings as mine: AC BR354 A 38
    I'd be grateful for any pointers on this one. Many thanks for your
    help thus far.

    Regards,
    Brian
    wb, Feb 21, 2005
    #10
  11. wb wrote:

    > On Fri, 18 Feb 2005 14:23:52 +0000, Pete C <>
    > wrote:
    >
    >
    >>On Wed, 16 Feb 2005 13:47:18 +0000, wb <>
    >>wrote:
    >>
    >>>>>Sorry, I've no circuit diagram but I've posted some photos here:
    >>>>>
    >>>>>http://fr.pg.photos.yahoo.com/ph/todayjustfor/album?.dir=/c9de
    >>>>>

    >
    >
    > snip
    >
    >
    >>Does it cut out even when no battery is connected?
    >>
    >>If so switch off and try disconnecting one of the wires from the
    >>secondary (non mains) side of the transformer that go to the black box
    >>on the heatsink.
    >>
    >>Then does it still cut out?
    >>
    >>If so it's likely to be a short in the transformer which is probably
    >>not worth replacing, if not it's likely to be the black box (bridge
    >>rectifier) on the heatsink which should be fairly cheap and easy to
    >>replace.
    >>
    >>cheers,
    >>Pete.

    >
    >
    >
    > Thanks Pete,
    >
    > It does cut out when no battery is connected but doesn't when I
    > disconnect either wire going to the black box from the transformer.
    > So, hopefully, a new bridge rectifier will solve my problem. Is this
    > the sort of thing I can get at Maplins - I've had a look but none has
    > the same markings as mine: AC BR354 A 38
    > I'd be grateful for any pointers on this one. Many thanks for your
    > help thus far.
    >
    > Regards,
    > Brian


    Any 10A 40V or better bridge rectifier will work.

    Often found on e-bay.
    The Natural Philosopher, Feb 21, 2005
    #11
  12. wb

    Pete C Guest

    On Mon, 21 Feb 2005 14:37:32 +0000, wb <>
    wrote:

    >It does cut out when no battery is connected but doesn't when I
    >disconnect either wire going to the black box from the transformer.
    >So, hopefully, a new bridge rectifier will solve my problem. Is this
    >the sort of thing I can get at Maplins - I've had a look but none has
    >the same markings as mine: AC BR354 A 38
    >I'd be grateful for any pointers on this one. Many thanks for your
    >help thus far.


    Hi,

    Looks like a 'BR354' is a 35A 400V spec:

    <http://www.alldatasheet.com/datasheet-pdf/view/RECTRON/BR354.html>

    Maplins do a 'KBPC3504' which has the same spec, for £1.29:

    <http://www.maplin.co.uk/Module.aspx?ModuleNo=19088&TabID=2&WorldID=&doy=21m2>

    Looking at a data sheet it's the same size with the same type
    terminals too:

    <http://www.alldatasheet.com/datasheet-pdf/view/SEMTECH/KBPC3504.html>

    When fitting the new one be sure the AC terminals marked '~' are
    connected to either lead from the transformer, and the DC terminals
    '+'/'-' are connected to the appropriate outputs of the charger.

    If you take the old one off and measure the resistance each way across
    adjacent terminals, you should find that 3 of the 4 diodes only show
    resistance one way, but one doesn't show resistance either way which
    proves it's defective.

    cheers,
    Pete.
    Pete C, Feb 21, 2005
    #12
  13. wb

    wb Guest


    >Looks like a 'BR354' is a 35A 400V spec:
    >
    ><http://www.alldatasheet.com/datasheet-pdf/view/RECTRON/BR354.html>
    >
    >Maplins do a 'KBPC3504' which has the same spec, for £1.29:
    >
    ><http://www.maplin.co.uk/Module.aspx?ModuleNo=19088&TabID=2&WorldID=&doy=21m2>
    >
    >Looking at a data sheet it's the same size with the same type
    >terminals too:
    >
    ><http://www.alldatasheet.com/datasheet-pdf/view/SEMTECH/KBPC3504.html>
    >
    >When fitting the new one be sure the AC terminals marked '~' are
    >connected to either lead from the transformer, and the DC terminals
    >'+'/'-' are connected to the appropriate outputs of the charger.
    >
    >If you take the old one off and measure the resistance each way across
    >adjacent terminals, you should find that 3 of the 4 diodes only show
    >resistance one way, but one doesn't show resistance either way which
    >proves it's defective.
    >
    >cheers,
    >Pete.


    Pete,

    Spot on in every respect. You're a real Sherlock!
    Many thanks and best wishes,

    Brian
    wb, Feb 22, 2005
    #13
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