RJH wrote:


Phil is right but I would wait until you have extracted it before
buying a replacement as it could be Ni-Cad or Ni-MH depending on the
age of the tuner, and they require slightly different charging
regimes. Equally it could be 3V, 3.6V or 4.8V although I would admit
that the size suggests the latter.


** AFAIK, Quad FM4s only ever used 4.8V NiCd battery packs with four cells specially made for memory back-up. It was trickle charged at a few mA whenever the tuner was powered up.

I doubt any re-engineering is needed to employ a four cell NiMH pack instead.


..... Phil