On Thu, 2 Jul 2009 13:09:02 +0100, "Clive George"
wrote:

"Peter Parry" wrote in message
news
NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

Is that really true? Are NiCds a lot less dense then? Eg AAs - what's the
capacity of a good NiMH vs NiCd these days? (2500 vs 700 mAH?)

Both have similar characteristics as far as their chemistry is
concerned. Because NiCd are due to be phased out there has not been
much development of them for a few years. As a result new
manufacturing processes are being seen in NiMH giving better
capacities for the same battery size. That said "capacity" figures
need to be treated with caution if you don't know the discharge regime
they were tested under. I've had NiCd 1AH batteries which had better
capacity than 2AH NiMH in one particular application.