Powerbook 1xx PRAM Battery question

[Ralphieboy]

Hi. I am rebuilding a nice PB180C.

Regarding the PRAM battery, it has been replaced but, date n time, memory, mouse, sound... reset each time I disconnect the power adaptor.

This machine, since its rebuilding has never been run with its main battery connected.

My question is: is the main battery that recharges the PRAM battery and not the power supply?

 

[beachycove]

The backup battery (not PRAM, as its functions are more extensive) will not charge until the main battery reaches “terminal voltage”, which in my experience is compatible with having an ancient main battery that gives you as little as 30 seconds of runtime. 

Equill on here used used to be the master of these matters. He/she has (alas) disappeared from the forum for a few years now. But you could search, further to which, here is one sample of many such archived responses to a similar question: 

 

[PB145B]

The backup battery in my 145B will charge with no main battery installed (however the 180 may be different).

 

[MikeatOSX]

It's always a good idea to have a spare interconnect board:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.at%2Fulk%2Fitm%2F152913585417