Re-chargeable AA /AAA batteries.

[pityacka]

Can these re-chargeable batteries be used without any worries or problems in film cameras ? Or can the slight difference in voltage; and also the Amh(whatever that is), cause incorrect meter readings; or possibly even worse- damage the camera circuit?
Been reading this a.m. where a man put re-chargeables into his Contax power pack/grip and it damaged the 167 camera.

 

[TheBigYin]

A freshly charged NiMh battery can put out maybe 1.65 volts which pretty rapidly sinks to around 1.5v for the bulk of the discharge curve. As it gets to the last dregs it drops away pretty quickly. So - they can be anything up to 10% over-voltage for something designed for your bog-standard Duracells. If the battery pack holds 4,6 or 8 AA Cells, then this extra voltage can be a material amount. I've had problems in the past with using multiple-AA rechargeable cells on high power LED's for my mountain bike, where the 6 cell holder ended up putting out just short of 10V, the led driver being built for 4.5v to 9v went up in a puff of blue smoke. My low-tech bodge was to run with 5x AA Cells and a dummy spacer cell.

As far as if it would damage any specific kit, or cause duff meter readings, my answer would be possibly, depending on the hardware.

 

[pityacka]

TheBigYin, Thanks for that reply. On another site it is reckoned that there should be no problem, but I agree with you that there could be a potential risk. I have a couple of slr's which need 8 AA batteries for the grips, and I see your point 8x extra voltage could affect things. To be on the safe side I might be better sticking to ordinary AA/AAA batteries, rather than damage the cameras.

 

[TheBigYin]

TheBigYin, Thanks for that reply. On another site it is reckoned that there should be no problem, but I agree with you that there could be a potential risk. I have a couple of slr's which need 8 AA batteries for the grips, and I see your point 8x extra voltage could affect things. To be on the safe side I might be better sticking to ordinary AA/AAA batteries, rather than damage the cameras.

The other option is to use the batteries for a short while to knock down their initial charge - if you've a multimeter, just use 'em until they hit 1.5v and they'll be fine - though with 8x batteries in there, you could get away with the "dummy cell" routine. My first attempt was a length of dowelling with 2 drawing pins - cut a thin groove along the length of the dowel - put pin in one end, wire around it, pushed into the groove, and down to the other drawing pin in the other end of the dowel. Run the kit on 7 and a dummy for a while, then slot the dummy out, and put your last real rechargeable in there. :shrug:

 

[Musicman]

Amh(whatever that is)

Amp-hours: essentially the capacity of the battery. The higher the rating, the longer it will last before it needs recharging.

Can these ... possibly even worse- damage the camera circuit?

Yes, it's possible, for reasons other than voltage.

NiCd batteries in particular have a low internal resistance, which means they deliver their current very easily. If the devices they're powering don't regulate the current they're drawing (because they were designed for batteries with higher internal resistance) it's possible that they can pull too much charge and overheat.

A relatively simple-terms explanation: http://www.flashlightreviews.com/features/batteries_explained.htm

 

[pepper]

Some cameras and flashes really don't like them!

Olympus XA flashes specify not to use rechargeable IIRC, and early Minolta cameras that take AA's don't like them either!

 

[srichards]

I thought rechargeables were nominally 1.2v instead of 1.5? I've always found them to be quite good in cameras. My old canon powershot would take 4 (!) pictures on normal AAs but rechargeables it would manage 40 or so with the high capacity ones.

If they are a bit too powerful then you could always use them in a flash gun to take the edge off them first perhaps?

Lithium AAs/AAAs are also good in high drain devices and they're better at lower temperatures.