Probably Nickle Metal Hydrite (NiMh.) Much more electrical capacity in the same size cell as older NiCd's.  No memory effect, and currently available in all the common cell sizes, with or without tag's.   The only thing you might have to do, if the charger is time based, is alter the timer so you get a full charge.    There are dozens of makes about, read the data sheets and choose a type that is suitable for your needs. High discharge current types however, don't often "keep" a charge for a "Long" time, so there is still some compromise. Regards. Dave G0WBX. On 05/01/18 17:00, time-nuts-request@febo.com wrote: > From: Ulf Kylenfall <ulf_r_k@yahoo.com> > To: Discussion of Precise Time and Frequency Measurement > <time-nuts@febo.com> > Subject: [time-nuts] HP 105B: Modern replacement for NiCad battery > pack? > Message-ID: <884302832.1124667.1515170814315@mail.yahoo.com> > Content-Type: text/plain; charset=UTF-8 > > > Gentlemen, > I may have asked this question before... > I am looking for a modern replacement for the NiCadbattery pack used in the HP 105B. One such 105that I salvaged have been standing on a shelf with thebatteries "happily boiling away". > So, what kind of chemistry would be possible to usewithout to much re-design of the charging circuitry? > Ulf Kylenfall > SM6GXV >