Pismo - PRAM battery sources or rebuild info?

Hey all,

my Pismo's PRAM battery (part no. 616-0108) is a goner. Just opened up the Pismo and yanked it out.

The only sources for replacement I've found online are sold out - does anyone know of a reliable one with some batteries left in stock?

If not, how difficult is it to build this beast yourself? Any tutorials?

I haven't opened up the pack but it looks like the cable connector is is simply soldered onto two pairs of button cell batteries in a row ?

Any help appreciated!
 

phunguss

Tinkerer
Dec 24, 2023
110
136
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I haven't taken one apart either, but it looks like two cells, 3rd wire may be the intermediary between the cells. If you are going to solder them, do it very quickly with a hot iron and lots of flux, as these LiOn batteries do NOT like to get hot (explode). Cool it down afterwards if you can (inverted compressed air will chill it out).
 

rikerjoe

Tinkerer
Oct 31, 2021
141
216
43
A while back I was researching information on building PRAM battery replacements for my PowerBook 5300 and Pismo and ran across this PowerBook PRAM Battery guide written in German. Perhaps this might help? The original color PDF is too large to add to this post, so I attached a grayscale version and here is a link to the original source. I haven't attempted the project yet.
 

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S. Pupp

New Tinkerer
Apr 2, 2023
53
16
8
Before obtaining a battery spot welder, I used copper tape with electrically conductive adhesive to rebuild my Lombard PRAM battery, which I believe is identical to the Pismo’s.

There are four cells (VL2330? Please confirm before ordering). Just slit open the brown wrapper holding them all together, and connect them with the copper tape in the same way they are connected by spot welding at the factory. I bought cells with attached tabs, and removed tabs (very slowly and carefully) from all except those that are soldered to the leads that go to the connector that attaches to the logic board. If not done carefully, you can open up the battery and leak electrolyte. A clue that this has happed is a characteristic odor.

After buying a spot welder ($50 from Amazon), the process was quicker. The first weld, however, opened up a cell and ignited the electrolyte. The cell casing is not rugged, and requires a low setting on the spot welder.