razor batteries.

[wheeltapper]

question for the experts, I have an electric razor that runs off of two rechargable AA size low capacity ni-cad cells wired in series and charged with a wallwart.
these are toast.

If I replace them with two AA high capacity NIMH cells can I charge them with the same wallwart?

cheers
Roy.

[seadog]

Probably not. They charge at different rates. There are chargers that can adapt to different cells but a cheap wall wart will not be in that category.

[philf]

question for the experts, I have an electric razor that runs off of two rechargable AA size low capacity ni-cad cells wired in series and charged with a wallwart.
these are toast.

If I replace them with two AA high capacity NIMH cells can I charge them with the same wallwart?

cheers
Roy.

Roy,

I'd say you'll most likely be OK. If the NIMH cells are of a higher Amp-Hour rating then you'll certainly be safe - it will just take longer to fully charge them.

Phil

[wheeltapper]

So far one against and one for.
And I'm no better off.

Anyone else have any input?

Cheers
Roy.

[seadog]

I'll add to what Philf said. It may take longer to charge or you may not achieve a full charge. It probably wouldn't cost very much to buy a Nimh rated supply from that well-known auction site. I changed the cell in a Dremel copy that I have, from Nimh to LiIon and bought a cheapo charger. I don't think it cost me more than £10 and I also got a spare cell for that price.

[Spurry]

Roy, please exclude me from the 'expert' category.  :-) When used in radio control models the nimh were always regarded as slightly inferior to the nicads that they replaced. However the chargers remained the same. The nimh had a higher self-discharge rate IIRC. The chargers only changed with the intro of the more exotic lithium batteries.
Pete

[eskoilola]

The voltage of these battery types is virtually the same. The charger will not see any difference from that point of view. However, if the charger is time-based rather than voltage based You may need to charge the NIMH batteries several times to charge them up to full capacity.

Other than the higher capacity and longer service life the NIMH batteries are a full replacement for old NICD batteries.

Do NOT throw the old NICD batteries to ordinary trash bin - they are problem waste and should be treated as that.

[wheeltapper]

Hi guys, they are in and it still works, so that's a bonus.
of course, when I removed the oid ones I found they were not AA but slightly shorter and narrower so the AA NIMH's wouldn't fit.

half an hour with a craft knife and hot iron and now they do fit.

It remains to be seen how they perform but it can't be worse.

Roy.