Help/advice on this old battery pack I found

Discussion in 'Electronics' started by mr. shr, Aug 10, 2011.

  1. mr. shr

    mr. shr MB Enthusiast

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    Guys,
    This old pack was left behind by seller in a house I recently bought. I suspect it's rubbish otherwise he would have taken it with him, but just thought I'd check here first.

    Question is, how can I test if it's any good?
    I've put a meter accross the crock clips and get less than a volt.

    There's a little DC socket on it (second pic). Can I connect a little DC adapter on it to charge the internal battery? What voltage to I put on it?

    There are no labels on the unit so don't know who makes it or anything.
    There's a cigarette ligter type socket on one side.

    What do you reckon? Bin it, or try and revive it?

    My mum's 211 needs jumping so would be good to have this working. (Don't want to jump it from my 211 if I can avoid it).
     

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  2. Ted

    Ted MB Enthusiast

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    Phew! you don't ask for much, do you?

    The D.C. socket is almost certainly the 'charge point' for this.
    If you could get a power supply which matches the plug, my guess would be 15v minimum 1 amp.
    To test if it holds the charge is simple, there should be some sort of capacity rating in ampere/hours A/H somewhere on the pack. I would expect this to be in excess of 20 A/H - prolly nearer 50 A/H
    When fully charged up, connect an old flasher bulb (say 21 watt) to the terminals.
    This should stay fully illuminated for approximately five hours for every 10 A/H of the pack - e.g. if it's 20 A/H expect the bulb to be on for 10 hours, 40 A/H expect the bulb to be on for 20 hours.
    Anything massively less than this means the battery in the pack is kaput.

    Please note that this is a VERY rough guide, and it still may not put out the high current needed for a jump start.

    Of course you could go to Costco and get a new one - I remember they were pretty cheap there.
     
  3. rf065

    rf065 MB Enthusiast

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    I had an identical one, used it a every monday morning on a works van with a dodgy battery that used to go flat when left over the weekend.

    After 5 or 6 weeks it could no longer hold enough of a charge to start anything anymore. Ended up binning it.

    Russ
     
  4. jaymanek

    jaymanek Authorised Forum Sponsor Authorised Forum Sponsor

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    thise are rubbish, throw it away for your own safety.
     
  5. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    Thanks Ted.
    I've got a couple of DC adaptors kicking about but none of them will be rated at 1A. Probably about 350mA or maybe 500mA. So I need to get hold of a 1A one.

    Don't think I'll be buying a new one. Just thought I'd try and get this old one going if at all possible.
    It's got an air compressor built in as there's a air filler type hose on the back.

    Would I be able to jump a car if the DC adaptor was plugged in? Or do you have to let it charge up, disconnect the DC supply and then attempt to jump start?

    And by flasher bulb, do you mean just use a car indicator bulb?
     
  6. BTB 500

    BTB 500 MB Club Veteran

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    These tend to contain a 17 Ah 12V 'gel' battery. As mentioned, it's useless without a matching power supply to charge it. Also these batteries don't like being left discharged, so if it's showing less than a volt it's probably had it anyway.

    These packs are about £30 new in Maplin, and periodically less on special offer. So I would bin this one.
     
  7. Ted

    Ted MB Enthusiast

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    I've got a couple of DC adaptors kicking about but none of them will be rated at 1A. Probably about 350mA or maybe 500mA. So I need to get hold of a 1A one.

    As long as it doesn't have current foldback (unlikely) the lower outputs should work (it will just take 2-3 times as long to fully charge

    Would I be able to jump a car if the DC adaptor was plugged in? Or do you have to let it charge up, disconnect the DC supply and then attempt to jump start?

    It really wouldn't help or make any difference, so I would not leave it plugged in.

    And by flasher bulb, do you mean just use a car indicator bulb?

    Yes - my (loose) calculations were based on a standard (21w) flasher bulb.

    As others have said, there is a good chance it's shot - especially if it's been left in a discharged state for a long time........

    But I'd give it a go! :)

    Edit if it is 17 A/H AND reasonably good dont expect much more than 5 hours from the bulb.
     
    Last edited: Aug 10, 2011
  8. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    OK fair comment guys.
    Ted, thanks for trying to revive, but you've been over ruled.

    Final verdict: This battery pack is heading for landfill. I'm not prepared to connect it to my mum's 211. They are sensitive enough as it is!!!
    Besdies, if this pack was any good, the previous owner would have taken it with him.

    Thanks for the support as usual guys.
     
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  9. SPX

    SPX MB Club Veteran

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    If you are anywhere near the rioting, try attaching it to the looters brains.
     
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  10. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    Optimistic to assume they have any.
    :wallbash:
     
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  11. GlenQ

    GlenQ Active Member

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    I have one of these that I have owned for over five years. I have always kept mine charged up and it holds its charge for months. It wont start a car if the car battery is totally flat but if the battery is able to turn the engine over (even slowly) this will give enough to start the car. I used this with great effect on my previous car, a 2005 Range Rover Vogue Diesel.

    I have yet to try it on my S500 but if it helps to start a 3Ltr 6cyl diesel I can see no problem with the S500.

    I also found the built in torch and 12v auxiliary socket useful.

    I suspect the internal battery is a NiCad and as others have said they don't take kindly to being discharged for an extended period. Have you used the voltage 'Test' switch to check the state of the charge?
     
  12. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    Pressing the test switch doesn't do anything. Should the needle move?
    Or should I put my meter across crock clips whilst holding the test button?
     
  13. horgantrevor

    horgantrevor MB Enthusiast

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    depend how long the battery was sitting uncharged

    but if you wanted to open it up remove the small motor bike battery size battery in it and replace then the battery back will be new

    remember to leave it on trickle charge all the time when not in use no need to bin it
     
  14. John

    John Hardcore MB Enthusiast

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    You should be taking all electrical waste to the tip a la 'WEEE'.

    Environment Agency - Householders
     
  15. GlenQ

    GlenQ Active Member

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    Flat battery

    Yes to show battery voltage and charge state.
     
  16. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    Well yes if I bin it, I'll take it to the local recycling centre.
     
  17. bolide

    bolide MB Enthusiast

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    £20 from Maplin. Damned good value - buy for for each car and one for the garage. That way you'll always be able to find one and find a charger for it. I killed mine by using a standard charger on it after I lost the psu

    The expensive ones are great but have a habit of going walkies. At £20 you don't have to worry about it

    Nick Froome
     
  18. grober

    grober MB Master

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    Junk it sorry. and tell your Mum to buy a new battery.
     
  19. OP
    OP
    mr. shr

    mr. shr MB Enthusiast

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    Which means me buying it and fitting.
     
  20. BTB 500

    BTB 500 MB Club Veteran

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    Bizarrely a replacement battery of the right size costs more than buying the complete unit.
     

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