PowerBook 2400c Backup battery

[KnobsNSwitches]

I've recently acquired a PowerBook 2400. It's delightful.

I have come across several posts about the Green Light of Death and it's relation to the the backup battery, but also posts talking about the difficulty of finding/replacing it.

Can anyone else who has owned one speak to how important it is to replace the backup battery? Thanks.

 

[KnobsNSwitches]

I'm going to add to this thread rather than start a new one.

Also on my 2400, I have a PCMCIA -> Compact Flash adapter. The CF card is formatted Mac OS Extended, so I can transfer files with my OS X Mac.

I have tried in 8.5, 8.5.1, and 8.6, and trying to copy anything larger than a text file to the CF card results in a system freeze. Downgrading back to 8.1 solved the issue. 

I've reformatted the card both on the 2400 and in Mac OS 9 on an iBook, and on my OS X desktop.

I was able to read and write in both Mac OS 9 and on OS X, and could read data from the card in any of the 3 other OS's on the 2400.

I don't know why, and I don't know that I really need anything above 8.1, but does any one know why that would be happening?

 

[beachycove]

The backup battery won’t charge, as I understand it, until the main battery charges to terminal voltage. So unless you have a working main battery, there is little point replacing the backup battery. Having said that....

As to replacing the cells: I did replace the cells in a 2400c,  and somewhere in the darkness of the archives there will be a post from me with the specifications.

As far as GLOD goes, if you had it, you’d probably know about it by now, as the thing just would not start up at all, or properly, or might only do so erratically. The symptoms can vary slightly, but anyway, it wouldn’t boot right.

If it’s working properly, you maybe have a good backup battery already. A working machine has almost certainly been maintained. To test the backup battery, put the 2400c to sleep, remove the power jack, remove the main battery, and then see if the light keeps flashing. If it does, and if it wakes when you put things back and open it up, you have a working backup battery. If it doesn’t wake, in the sense that it has died and needs rebooted, then you do not have a fully functional backup battery. If you’ve lost your pram date settings, etc., then the backup battery is toast. A really good backup battery will maintain the machine while sleeping for 10 mins or some such.

When I replaced the cells in mine (with Varta something or others - I forget), the originals were on the verge of leaking into the machine. Best have them out if there is any dubeity. 

 

[KnobsNSwitches]

Thanks for the info. Seems like mine is dead. My main battery does hold a charge (for nearly a half hour in basic testing!) but removing battery and power adapter results in the machine dying, and losing time and everything. 

I've found one place still selling the pram/clock batteries (for nearly $40!), so I have to see if I can find anything else.

 

[beachycove]

Couldn't find my old post on here, but on further investigation, the stock backup battery in the 2400c consisted of three (Varta) V110H cells. These seem no longer to be manufactured, but higher-capacity V150H button cells can be used as replacements for the V110H. I have done this and it works. I see that there are oodles of these V150H cells on eBay, including some that come ready-assembled in a pack of 3, for $20-ish. You just solder the wires onto the tabs. Mind you, you more or less have to disassemble the PowerBook to get at them....

Note that a PowerBook will ordinarily take a day or two on the charger to replenish a backup battery. If you haven't done that, you might want to try it first as well.

 

[MikeatOSX]

Look for 3.6Volts battery 110 (150) mAh Ni-MH (3x 1.2Volts):

www.welovemacs.com/b4541.html https://www.amazon.de/dp/B001BSCXRI/ref=cm_sw_r_sms_awd_qgKTwb608ZF3E