Bike light Battery replacement

stigofthedump Posts: 331
edited January 2012 in Workshop
A short circuit has destroyed the battery pack for my Light. It is a Nightpro extreme HID light with a Welch Alleyn 12.8 to 13.4 volt 10 watt HID bulb. I cant find a spare battery for this light.

What options do i have for replacing the battery. I was thinking of getting 4 3.7 volt 18650 cells and wiring them up in series to make a 14.8 v battery. But i am not sure how i would charge this exept by charging each cell individually. I am handy with a soldering iron and i am happy to make battery holders and connect the cables up.

I know i can get a £40 LED light from deal extreme, but the light from my HID light is much better and i want to keep it.

All advice gratefully accepted


  • rake
    rake Posts: 3,204
    what type of batteries are they. are they in a seperate pack .
  • craker
    craker Posts: 1,739
    4 3.7 volt 18650 cells and wiring them up in series to make a 14.8 v battery.

    I think this is your best chance. It needn't be too much of a chore- I've got 18650 battery packs for two batteries (8v) and a x2 charger. Depending on how pressing recharge time is for you (it's about 5 hours for a pair) you could get away with one charger (of course there are probably 4 battery chargers). You'll have to remove the batteries from the packs each time though.
  • rake
    rake Posts: 3,204
    dont nimh batteries have the same charge density but just weigh slightly more. 11 would give 13.2v. can be made into packs and charged as so.
    infact looking here they are indeed 4.5A/h nimh batteries. can find those anywhere. model shops and the like. you will be able to use your current charger.
    i suspect they will be subc size batteries at that amerage. nimh are by far the best value, greenest and fairly rugged batteries capable of many charges, in the 1000 ballpark i think.
    more here
    according to Marwi website who make this light its a 12v 4.5A/h nimh. so 10 cells.