On 07/02/2019 12:52, NY wrote:
The bog standard rechargeable batteries (750 mAhr) in our DECT phones
are starting to lose their ability to hold their charge: they indicate
full charge but the phone cuts out with "low battery" within a few
minutes of being taken off the charging base station, especially if used
on speakerphone.

Is there a problem with replacing them with batteries that can hold more
charge ie 750 mAhr. I presume the phone will still charge them at its
standard rate (though it may take longer to charge them).

So long as you use batteries with the same chemistry as the originals
then there should not be a problem. Phone makers just use the cheapest
(ie low capacity) ones that can reasonably get away with.

Some phone chargers are as dumb as a rock and continue to charge already
charged batteries eventually killing them (or rather making them
unwilling to discharge anything like their full capacity when required).

I will go for branded (eg Duracell) rechargeable batteries.

That is a very bad idea. The *only* batteries I have had leak on me in
the recent past have all been genuine Duracell. You can find threads
bemoaning the problem in s.e.design. Panasonic or Everyready are still
reliable battery brands. Aldi/Lidls were good and at bargain prices in
the past - they are less so now and more variable.

I presume that if the original batteries are NiMH, I should go for that
same technology.

Not should *MUST* - likewise if they are NiCad replace with NiCad.
NiCads tend to suffer memory effect and so lose capacity quickly.

--
Regards,
Martin Brown