Beginner needs help with broken car/truck battery charger

Discussion in 'General Electronics Chat' started by macnee, Jun 28, 2010.

  1. macnee

    Thread Starter New Member

    Jun 28, 2010
    Hi all, i done a search but didn't come up with anything that relates to my problem.(if their is please point me in that direction)

    Please be patient, im not the best at electrical currents and thing, so anything i leave out please ask and i can find out or give pictures if needed.

    So i will try to keep this short, but give as much detail as i can.

    I borrowed a charger to try and start my van, the battery was still in vehicle, its a heavy duty upright charger. (sorry no name or info on the outside.

    The charger has 4 settings 12v normal, 12v boost, 24v normal and 24v boost, i first connected it and put it on 12v normal, for about 25 mins, was reading about 14-15 amps on the needle tried the van and still dead, i was told to give it a boost for a few minutes which i done, out put of about 35 amps (again by needle dial on charger) to no avail.

    Well after the next try i took all connections off battery, cleaned and checked and then re-connected, connected charger and tried again on boost, this time the charger made a clicking noise and the needle dropped to the bottom, with no movement.

    I unplugged the charger, checked for any problems or burning smell, all seemed o.k, went to re-connect and their was a big spark from the + terminal.

    Now this confused me as the charger was unplugged, i tried again and the same thing happened.

    I assumed the battery was just beyond or maybe shorted or something, so i tried the charger on my good car battery, still the same, sparks and no needle movement.

    I took the car battery out and tried again, still sparks with battery out and charger un-plugged, no needle movement, i also tried on an un-charged battery aswell, still the same thing happens.

    So can anyone please help me repair this charger, if you need any more info please ask and i will do my best to get it for you.

    i can provide pics if needed. i have taken it apart and looked for anything out of the ordinary.loose wires, burning smells, broken wires and everything looks normal.

    Please please help
    thanks wayne
  2. SgtWookie


    Jul 17, 2007
    Hello Wayne,
    Without a manufacturer or model number, we're going to need some good clear photos of the board and various components, just for starters.

    It's difficult to take really good, clear photos of circuit boards. The best lighting you can get is outside on an overcast day, as the lighting is very even.

    Don't use direct flash, as the images will be very harsh and contrasty.

    If your camera has a macro function, use it.

    Fuzzy images won't be of much use. We need very well-focused images.

    Upload the images to the forum using the "Go Advanced" and "Manage Attachments" buttons. Be aware that there are limits as to the size and type of files that you can upload.
  3. macnee

    Thread Starter New Member

    Jun 28, 2010
    Thank you i thought you would need pics, but didnt want to waste your time, just with randoms stuff, i will get strait onto it, i will take a pic of the outside, any labels/info inside and all the main parts.
  4. macnee

    Thread Starter New Member

    Jun 28, 2010
    Ok i have done as you asked, used macro and the pics come out very clear i think, i can get closer if you need.

    Some of the distance photo's are a little fussy, but this was just to show where parts are in relation to other each other.

    Every part of the charger has been pictured.

    Due to the amount and size of good quality pics, i have used photobucket to host, so here is a direct link to the album. pictures/

    I have also numbered the pics, so can you use numbers when you describe or ask questions as it will be far easier for me to help, as i'm not sure of part names.

    Thanks for your help
  5. gerty

    AAC Fanatic!

    Aug 30, 2007
    Sounds like either the cables are shorted together, or the diodes are shorted.
    Check the cables for any bad spots on the insulation, exposed copper wire.
    Also check where the cables enter the charger.
    If all that is good, time to get a meter and check the diodes (pics 4&5).
    They are the bolt looking devices, they should conduct electricity in one direction but not the other. Their function here is convert ac (alternating current) into dc (direct current) which is what the battery needs.
    If the diodes are shorted it could cause the sparking you describe.
    If you don't have a meter:
    Unbolt them from the aluminum heatsink, don't let them touch anything, and try connecting the leads to the battery. If there is no spark that is probably the problem. When putting them back make sure you have all the washers in the proper places, pay attention when dissasembling.
    Picture #8 is 3 circuit breakers wired in parallel.
    Picture #6 is some sort of power resistor, not sure what it's used for here, the left end in the picture looks a little burnt. Make sure no part of the wiring is touching the bracket or frame.
  6. loosewire

    AAC Fanatic!

    Apr 25, 2008
    Sarge,That a good reminder of lighting for all of
    the members. The pictures on this forum have
    gone to the next level of self service.
  7. macnee

    Thread Starter New Member

    Jun 28, 2010
    Thank you very much gerty, i will try this as soon as i can.

    i have checked all cables, but will go back and re-check just to make sure

    Can anyone give me the name of the diodes, what type, thought id just replace them anyway, if their fairly cheap.
    Last edited: Jun 30, 2010
  8. SgtWookie


    Jul 17, 2007
    Those rectifiers with the I R logo on them are International Rectifier parts.

    You didn't show the part number side of them. Try reading off the numbers and posting them.