2400 clock battery replacement

[Durosity]

Hello!

I'm trying to salvage a 2400 logic board that was slightly battery bombed. I've done a few on board repairs and a couple of trace repairs, and it now bongs, but nothing comes on screen (nor external screen). I don't get a GLoD. I'm sure I read on another post a while ago that these machines need a clock battery to work. Does anyone know what the voltage of the battery was so I can try simulating it to see if that helps?

 

[3lectr1cPPC]

The 2400 does not need a functioning clock battery to work, this is an untrue myth. Sounds like you're still missing some bad trace or connection somewhere. Got pics of your logic board?

In any case the 2400's clock battery is a rechargeable 3-cell NiMH pack made by VARTA, 7.2v IIRC. I'm somewhat sure that it's 110mAh originally.

 

[Durosity]

untrue myth

I had a feeling that may be the case, but just wanted to rule it out to be sure.

I’ll post a pic of the board later on. It’s entirely plausible I’ve missed something.

 

[Powerbook27364]

The 2400 does not need a functioning clock battery to work, this is an untrue myth. Sounds like you're still missing some bad trace or connection somewhere. Got pics of your logic board?

In any case the 2400's clock battery is a rechargeable 3-cell NiMH pack made by VARTA, 7.2v IIRC. I'm somewhat sure that it's 110mAh originally.

Mine is running with no pram battery. I just got mine working the other day and have a failed inverter and cracked display. It should be a standard vga output. If you shine a flashlight on the display can you see an image?

I did notice that I had to boot it with vga plugged in to get an output and if I plugged it in afterwards it would not display.

It is a 110mah battery but I don’t remember the voltage, it’s 6 cells though so im certain 7.2v

Make sure to check continuity on any darkened or suspicious traces and especially between sides of the board as those are very easily damaged. Focus on anything that had corrosion on or around it and check the legs on the chips as well. Pics would be very helpful to determine the damage and what’s affected.

 

[3lectr1cPPC]

I thought it was 6 cells too, in fact, my website still says that. But upon looking closer, it appears to be 3.

Here's a 6 cell VARTA out of a Dell Latitude C640 to compare.

 

[Powerbook27364]

Huh I’ll have to check later when I get home from work. I do remember almost buying a 3 cell replacement though so maybe I’m forgetting what it really is. I know I have a 6 cell 7.2v battery but it was from the Toshiba (which I still need to get a charger for) I own so probably mixing them up.

 

[3lectr1cPPC]

Yeah there were all manner of cell types.
IBM ThinkPad 701c has a 1 cell.
Many Sony VAIO laptops have 2 cell ones, as does the PB 150.
3 cells were used in many Toshibas, the WinBook XP/XP5, numerous ThinkPads, others.
Not aware of any 4 cells actually, or 5.
6 cells were used in many Toshibas, Dells, PowerBook 3400, many others.
Some Toshibas even used these gigantic nightmares: https://www.ebay.com/itm/325183050322
Not even sure how many cells there are, maybe 6 of the larger cells used in the 2400 battery.

 

[Powerbook27364]

It’s a 3 cell. As long as you can find cells that fit inside the little space, you should be able to rebuild/replace the pack. The original pack is about 43mm x 27mm x 8mm

 

[3lectr1cPPC]

Original cells are Varta V110H from the looks, seems to be that the V150H are what’s available now, higher capacity.
I honestly wouldn’t bother though. Getting a 2400 apart is a challenge and it would be pretty darn easy to forget about the new ones and then 20 years from now you’ve got another problem.

Only good reason I see is if you’re going to be using main battery power a lot. I’m going to install a batt in my 3400 which also uses a varta pack simply because without one you can’t swap out the battery pack for another and boot without a jump start from the charger. I have no idea if the 2400 is the same way though.

 

[Powerbook27364]

Mine boots right up when I plug the battery in so it seems to be fine without the clock battery for that. Very unusual since my duos which aren’t much older need that jump start.

 

[3lectr1cPPC]

Ah ok that’s good to know. So yeah the benefit you would get (basically just time and date) just doesn’t seem worth it to me for the leak risk in the future. Up to you though.