Intelligent NiCd/NiMH charger

[John Stumbles]

I'm looking for a charger for AAA, AA and C size (and ideally also PP3) NiCd and NiMH batteries which fast charges with delta V sensing to cut off each cell when fully charged. AIUI the delta V which signifies full charge is different for NiCd and NiMH (-ve for NiCd, +ve for NiMH?).

I think there's a Varta charger which does this: there was a Green shop in Hastings doing them for £20 last year but they've closed now and don't have any stock left. I'm told there's someone doing them at a subway under Waterloo Station (at an address that sounds rib-ticklingly like the address to send the money to in Monty Python's Blackmail :-).

Maplin do a 'Vanson' (who they?) charger for £30 but it only talks about -ve delta V. (Vanson's website - quovadis.tv doesn't even mention this charger, and other retailers' websites say nothing except claiming intelligence of charging).

Any suggestions?

Bonus points for one which runs off a 12V supply too!

tia

-- John Stumbles

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[The Natural Philosopher]

Go to a model shop, or look at some of the online model shops.

I have modified all my rechargeables to be 'model compatible' so now have a vast array of interconnection leads to plug everything into various chargrs I sue for eth electric aeroplanes.

Biggest problem will be e.g. cell holders to charge multiple cells. I solved this my using packs of cells with model style connectors on them and throwing away teh 'in appliance' cell holders. This may not be possible for some kit.

Check out brands like Schulze, Supernova etc etc.

Good chargers ain't cheap tho. Expect to pay up to 50 squids for a halfway decent one, and up to 500 for a top of the line bells and whistles one.

Conversely, the one I use most is sold for car racers at about £25, and does 6-8 cells off the mains at 3.5A with delta peak - its a bit hard on the 500ma/h and 1100 ma/h cells, but fine for AA sizes and up. But you can always trickle them...

[Jack]

"John Stumbles" wrote in news:yIpXa.4572$ [e-mail]:

google: Ansmann

Cheers

[parish]

I just got a Uniross fast (2 hour) charger that uses delta V sensing. Mine only does AA and AAA but they do others. Mine came complete with a mains brick *and* a car cigarette lighter adaptor.

[Alan]

Have a look round

I bought an Ansmann charger from them a few months back and it's been great.

Alan.

[John Stumbles]

To answer my own question (since none of you useless shower did ;-) I did what I should have done in the first place and googled sci.electronics for delta V. My synopsis is: both NiCd and NiMH show a -ve dV at full charge, as a result of temperature rise i.e. +ve dT (which is maybe where I got the idea I had about +ve dV).

With NiMH the effect is much smaller than with NiCd so a NiMH charger can be used for NiCds but not (necessarily) the other way round.

Thanks to everyone who replied re Ansmann, Uniross and model chargers. The latter I'm interested in for big sprog's Nikko arsey car and maybe some cordless tools (but these have 14.4V, 18V and 24V packs) but for the range of 1, 2, 3 and 4-cell toys and appliances around the house a discrete cell charger is the only way to go.

cheers

-- John Stumbles

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