Need an On/Off Switch for AA Battery Pack

I have an Omnibook 425 that runs on four Lithium AA batteries. The OB sleeps more than it powers down, so the batteries drain out over night, despite using the machine's Power Off button.

The case's plastic/hardware is now 25-years-old, so I'm loath to keep pulling out and reinserting a single AA to stop the discharge.

At this point, I'm taking the English Major's approach (read primitive) of simply inserting a strip of plastic between one end of one battery and the pack. While this reduces the frequency of pulling the batteries, I'm still having to open/reopen the fragile battery cover.

Ideally, the plastic strip should be a strip that is conductive/nonconductive by the means of a switch. I haven't found anything that can do that, perhaps because only an English Major could think of something so stupid.

So I turn to the forum's engineers or at least people who studied harder than I did.

Any ideas?

I suppose I could cut a physical slot in the battery cover that would allow the insertion of the plastic strip without removing said cover. But I'm sure I would crack the cover while cutting and the entire idea is so ratchet that I'm embarrassed to even type it.

Jake

Maybe this will work?

I think it might be better to have one with thicker wires? (the amazon one) not too sure.



This Japanese page might give you the idea of what I'm thinking, but proceed at your own risk.
http://scw.asahi-u.ac.jp/~sanozemi/Sakuhin/NotePC04/NotePC04.html

Edited by stingraze 2022-01-12 2:15 PM

Had a look at my own 425. I see several options:

a) light intrusive: separate one middle connector into two, solder small wires to both sides, and lead these outside to a switch.

b) non-intrusive: acquire a small piece of double sided printed circuit board, cut to size to fit to one side against the batttery clip, solder wires to both sides and lead these out to a switch. Insert the (battery connector sized) board at one of the sides between batttery and connector (i checked, this will fit).

In both cases, when the switch is off the circuit is broken. On-connected.

If this is all too technical for an english major , PM me where to send the working solution b to... (lots of circuit board, wire, solder and switches laying around)

Michel

Edited by michelbel 2022-01-12 4:29 PM

stingraze and michelb, many thanks for posting your suggestions. Michel, I've sent you a PM since this sounds above my pay grade.

Thanks again,
Jake

Well the JBSD is ready (Jake's Battery Saving Device ), to be send all the way from the EU to the US

This very complex device(switch, PCB, wire) (see : ) sits on the side of the battery pack, and keeps the batteries from seeing each other until the switch is on:
Below a few more pictures how it works:



The last picture above shows where the OB425 has a modem slot (usually unused) where the switch might be put in.

What a treat! I'm stunned and amazed; never could've done it myself in a million years. My 425 does not have a modem installed so that's where I'll hope to place the switch.

Michel, I can't thank enough. Lithium batteries everywhere are dancing in the street

Jake

Epic

I guess my question would be this: Doesn't this cause a hard reset requiring you to have to reinstall software or at least a backup every time?

I'm thinking I'd rather install a simple jack with which I could connect with a power supply to prevent battery drainage.

Oh, it has got a jack for a 12V 3.5A negative tip charger. But that does not necessary stop the drainage if you do not plug it in..I personally think Jake's OB425 has a slightly leaky condensator somewhere, but often these are hard to spot. A swollen electrolyte is easy to spot, but other caps may be hard to analyze. And it has it's software - full Dos+Windows 3.1 +Word+Excel in PCMCIA XIP (eXecute In Place) 12MB rom memory. And it writes tp PCMCIA flash, not to internal memory at all (except temporary) so you lose nothing. But (if not losing battery power) it still is 'instant on'

And it came with a NiMH battery pack that can be charged inside. But somehow these run out after 26 years . However, connecting two of the three charger clips will allow charging normal NiMh cells - except I have not yet tried that out (too lazy to ohm that out yet), I just recharge the four NiMH AA's externally. But there is no intelligence inside the battery pack, so replacing the inside NiMH's with four new (short form) ones will revive the (chargeable) pack. etc, etc

And Jake, bubble envelope is on the way.

Edited by michelbel 2022-01-16 8:55 PM

Exactly my point...plug it in...rebuild the battery pack if necessary.

On a side note...we are not that far away from having nuclear powered batteries available to the common consumer.

The hard part is finding the battery pack, not necessary the rebuild...

My eternal thanks, Michel. PM your address when convenient so I can track down a good post card.

Jake