Recharging 1.2 V rechargeable batteries

Discussion in 'DIY' started by Spacehopper383, Nov 22, 2010.

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  1. I've noticed that 1.2 V batteries are becoming more and more common instead of the old 1.5 V stuff, my question is can I use an old battery charger to charge them or do I have to buy a new one.

    The charger I have is all singing all dancing and discharges all the batteries before charging them, plus it stops charging once the batteries are fully charged. Although it does this, the batteries I got with it and one I have bought since are all 1.5 V and I am worried that I might over charge the 1.2 V batteries and be left with a dead ones or worse.
  2. All common rechargeable batteries of the AA and AAA sizes are, and have always been, 1.2V. Your charger will be OK. 1.5V batteries will be of the alkaline or zinc carbon type and shouldn't be recharged (though some people claim that you can "refresh" them in purpose-made chargers - IMHO, twaddle).
  3. To add, modern rechargeables will be nickel metal hydride (NiMh), old ones will be nickel cadmium (NiCad). Look at the markings on your batteries, if they don't have these markings, don't recharge them (explosion or fire can result).
  4. Your rabbit vibrator will work better with 1.5 volt alkaline types which you can refresh after they are exhausted by putting them in a warm oven for 15 minutes. No, not a microwave oven.
  5. I disagree. You'll get a more explosive orgasm with 1.2V rechargeables. You could try nearly discharged alkalines, but you run the risk of them dying at a crucial moment.
  6. Heh heh heh! I defer to your superior experience!
  7. Putty, I thought your were talking balls, but after looking closely at all my rechargeable batteries, I've learnt another thing, for almost 35 years I thought rechargeables were 1.5V.
    Who says you can't teach an old dog new tricks.
  8. I haven't got an answer for the next obvious question, "Why don't they stick an extra 0.3V in rechargeable batteries to make them fully compatible with the non-rechargeables that they're intended to replace?"
  9. I too have wondered that ... and courtesy of Google a possible answer ... it is associated with the chemical reaction wich generates the Voltage .... see linky ... why do rechargeable batteries have only 1.2 Volts?

    Edited to add ... hope I have not been taken in Hook line and Sinker .
  10. Grumblegrunt

    Grumblegrunt LE Book Reviewer

    there used to be a period where a lot of 80's electronics wouldnt work with 1.2v but they addressed that.

    a bigger issue with chargers is the way they charge and the increase in battery capacities, I have found that a lot of chargers are older spec than the batteries so dont actually charge them fully as they trip off when the battery gets hot which I think is something to do with resistance and the like. if I'm off somewhere and want full charged batteries I have to charge once, let cool then charge again or topup the batteries before I go off, otherwise especially in my little DAB it only reads as half charged and gives me about 2 hours, if I double charge then I can get up to 6.

    the batteries in my outdoor lights are 600ma but the ones I buy for electronics are 2400ma
  11. Very, very true. But if you're using one of the older chargers that offers the choice of charging two or four batteries, you'll also find that when one of the batteries reaches full charge, the whole charger switches off, potentially leaving you with three batteries that barely have any coulombs in them. Repeat charging will put a bit more charge into them, but not much more. More modern (and costlier) chargers allow the option of charging 1-4 (or even 1-8 ) batteries at a time with each battery individually managed. It's worth the investment.