Author Topic: can't find backup battery replacement for 12" powerbook.  (Read 1031 times)

Offline part12studios

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can't find backup battery replacement for 12" powerbook.
« on: March 29, 2020, 09:46:09 PM »
Hi everyone,

I know this is a post-OS9 computer, but i think we have enough mac enthusiasts here who appreciate legacy OSX hardware too so I'm going to pose this question.

I've opened up my 12" G4 1ghz so far.  I have a 1.0, 1.33 and now a 1.5ghz 12" powerbook (several "for parts" units to make 1-2 100% restored)

I'm trying to pimp out the 1.5ghz unit.  However all three of them show that they have dead backup batteries for clock.  I opened the slowest of the three since that's pretty much going to be the "for parts" (slow man on the totem pole) and i was optimistic that i'd find a user replaceable battery, but no dice.  it's this small battery soldered on.  i can't find any online references of what this battery is.  nothing on ebay and no luck googling in general. 

I'm also seeing if this is something that would require the logic board be completely removed to change or if it's a surface soldered piece?  probably taking it to a local professional to have the work done once i know i have the right part. 

Thanks!
Caleb

Offline part12studios

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Re: can't find backup battery replacement for 12" powerbook. (resolved)
« Reply #1 on: April 02, 2020, 12:59:47 PM »
man it's quiet around here.. this posting still on the top?   So I have some interesting news about the battery for those like me who didn't know..  it turns out that these older mac laptops (and maybe newer ones?) don't use a "battery" but instead they use a "capacitor" to save the clock information..

this is the one for the powerbook.  5.5v capacitor.  $7 which is about right for something like this:
https://www.thebookyard.com/product.php?products_id=1884

So for mine I'm testing something to see if it's actually bad now that i know it's not a battery.  Following a friend's suggestion i did a PRam reset and i've let the computer charge while on for 24 hours..  then i'll shut it down and take the battery out and see after another 24 hours if the clock information is in tact or not. 

Offline GaryN

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Re: can't find backup battery replacement for 12" powerbook.
« Reply #2 on: April 02, 2020, 06:20:23 PM »
Ummmm… The cap you're referencing is NOT substitute for a battery. That computer doesn't have a small backup battery - it relies on the main battery to keep the PRAM settings, the clock and such alive. That cap is there ONLY to hold the PRAM voltage up during a main battery swap.

Your planned 24-hour test is roughly 23 hrs and 59 min longer than necessary. That cap will discharge in less than a minute.

Offline part12studios

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Re: can't find backup battery replacement for 12" powerbook.
« Reply #3 on: April 02, 2020, 08:32:30 PM »
ah ok that makes sense. even better!  with that i'll test further.  i have a decent battery in it that is good for about an hour..  i just want to be sure the thing retains the time which it wasn't, but i'm not sure what situation was dictating this. 

I do believe though that even with the good battery my clock isn't being remembered, but maybe the battery not in at the time in hindsight. 

just wanting to be sure it's 100% before i go in and replace the drive with a new mSATA 2.5" SSD.   Already have it maxed it with memory and i want to replace the bluetooth only wireless card with one that supports wifi..  i took the card from my 1.0ghz that has wifi.  hoping the models are close enough that the cards are a 1:1 swap. 

I also have a 2nd battery that's 100% dead.. but i learned how to open them and what kind of battery cells can replace them so that's a project for the 1.33ghz powerbook.