Highest current delivery: old NiCad or new hi-capacity NiMH?

I would like to know which of my rechargeable cells can deliver the highest current.

I have some new high capacity NiMHs (1800 mAh and 2200 mAh).

Can these NiMHs deliver more current than older NiCads? (500mAh or

800mAh).
Reply to
John X
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I don't know enough to tell whether or not his numbers are correct, but he doesn't know what he's doing wrt units: he has internal resistance listed in terms of watts, rather than ohms. That alone would raise some doubt in my mind about the accuracy of his data.

Reply to
David Kerber

I don't know if NiMH can deliver as much current as NiCd.

However, in a camera flash a NiMH recharges the flash capacitors about as fast as a NiCd.

(The flash charge circuitry is the limiter, however. Much better than alkaline in both cases...)

NiCd's are otherwise lower capacity, discharge-finicky and sensitive to shock. I haven't used mine in over 7 years. Don't intend to either.

Reply to
Alan Browne

I did some minor research a while back and found that for the same physical size cell, NiMHs could generally deliver as much or more current while holding the voltage up than NiCds. NiCds look more impressive when the drain is expressed in terms of the capacity C, but the capacity is enough less than NiMH cells to give the latter an advantage in terms of absolute current. If you compare cells with equal capacities rather than equal sizes, NiCd cells do usually have the advantage. But to get the real low-down requires looking at the data sheets of the specific cells you want to compare.

Roy Lewallen

Reply to
Roy Lewallen

Could that be milliOhms? Sometimes I see the omega inadvertently converted to W in some text conversions.

Reply to
RFI-EMI-GUY

The low self-discharge NiMh cells like Sanyo Eneloops and Uniross Hybrios can hold up their voltage on load a little better than normal NiMh. Eneloops keep over 1v at 10A load. Here's a load of discharge curves for many AAs and a few others....www.candlepowerforums.com/vb/showthread.php?t=79302

Reply to
Steve B

That's possible; I didn't think of that.

Reply to
David Kerber

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