I'd get rid of it- I really don't trust those things. I had a couple of those leak back in the 90's when 486's were new, and we were using the PC every day.

I've seen literally dozens of PC and Amiga boards that have been damaged or destroyed by those things.

They seem to all leak eventually. If you look at the board every day, I think you'll catch it before there's much damage, but it would be easy to forget about it for a year or two, and then...

The ones I'm familiar with are Varta 3/V60R. Its a Ni Cad, so needs to be run every once in a while to hold a charge. They have little tabs on them, sometimes two on one end. Those tabs seem to be spot welded to the battery - I was unable to desolder them. I think you are supposed to desolder them at the board. I crudely cut mine out because it was leaking badly. The blue-green leaking crud looked bad, but didn't seem to actually do any damage once cleaned off.

You can still get new ones, but I'm not sure that they haven't been sitting for 15 years already. There should be a better replacement idea, but would probably require some soldering at minimum. Most newer computers use something like a CR2032, which is a different voltage (might be close enough) but the motherboard will try to charge it, which might make it blow up.

Best options I can think of so far are:
Cut the tabs off with some space for soldering
Solder some wires onto the board to run to a new battery
Run them to a different battery mounted somewhere in the case - either a real NiCAD (anything with 3.6 volts should do), or possibly a modern cell with some diodes in series to prevent charging.

I've only done steps one and two and wasn't successful in using another battery, but at least stopped the damaged to the board and didn't kill it in the process. Attached is what it looked like.. don't laugh at my soldering job, it was awful (and one wire fell off). Anyway the board looks crummy but cleaned up ok.

With those barrel type batteries you might want to snip off the legs as close to the battery as possible then solder your new battery holder to the legs of the old one that way you don't have to work so close to the motherboard and there is less risk of damaging anything.

sliderider wrote:

With those barrel type batteries you might want to snip off the legs as close to the battery as possible then solder your new battery holder to the legs of the old one that way you don't have to work so close to the motherboard and there is less risk of damaging anything.

+1. I usually do the same thing. Only that I don't solder any new batteries. I just use the external battery connector and a battery holder.

Markk wrote:

sliderider wrote:

With those barrel type batteries you might want to snip off the legs as close to the battery as possible then solder your new battery holder to the legs of the old one that way you don't have to work so close to the motherboard and there is less risk of damaging anything.

+1. I usually do the same thing. Only that I don't solder any new batteries. I just use the external battery connector and a battery holder.

What I meant was if you wanted to solder up a coin cell or AA holder. It's easier if you have something to solder the leads to instead of soldering directly on the motherboard.

yeap, I know. For me it's easier also, as I can do that with a wire cutter. No need to wait for the soldering iron to heat up. 😀

Thanks very much for the replies, I'll take the advice get rid of it. I've de-soldered one from a another board and used the external battery header, which worked OK. So I'll go that route again if I can.

The 386DX40 board I mentioned in the original post is dead - can't get it to post. But I can't bring myself to throw it out either, it seems like such a waste. Maybe I'll hand it on the wall.

Now here's a question I have, has anyone tried getting a 3xAA holder, soldering that to the board, and using 3 NiCd or NiMH batteries in the holder. At 1.2v each, they would have the same 3.6v output as the barrel battery, but would it work, charge, hold a charge, blow up, etc. Seems like it might be easier to replace later on than barrel batteries.

NiMH would be very dangerous to do that with - they are tempermental on how they are charged. not nearly as bad as lithium types though! NiCD would be perfect but remember they can leak like the originals, too.

jaqie wrote:

NiMH would be very dangerous to do that with - they are tempermental on how they are charged. not nearly as bad as lithium types though! NiCD would be perfect but remember they can leak like the originals, too.

True, but NiCd AA's would be much easier to work with and replace, and you can get cheap new ones at Dollar stores in places. Might be a better option than buying 15-20yr old stock barrel batteries.

I'll stay away from the NiMH's though, don't need anything exploding in a 386 😀

maddmaxstar wrote:

Now here's a question I have, has anyone tried getting a 3xAA holder, soldering that to the board, and using 3 NiCd or NiMH batteries in the holder. At 1.2v each, they would have the same 3.6v output as the barrel battery, but would it work, charge, hold a charge, blow up, etc. Seems like it might be easier to replace later on than barrel batteries.

Yep, Chuck(G) at VCF actually reccomends using 3x Alkalines, with a 1N4002 diode, all in series. This gives you just about 3.6V
I'd still make sure to mount the batteries well out of the way of anything they can leak on.

I've actually bought and used a couple of these before:

http://www.mwave.com.au/sku-49170021-AA_Exter … erboard_Battery

They're fairly expensive, but they're a minimum of fuss. I've had one in my 486 for a couple of years now and its still humming along fine.

Since we're talking batteries, here's the sucker from my 286 portable:

20120221-IMG_7307.jpg by squallstrife, on Flickr

20120221-IMG_7306.jpg by squallstrife, on Flickr

Why do you reckon it has that little resistor in series with it?

So it doesnt turn into a grenade when shorted

If it's a 3.6V battery, the Macintosh battery may also work here, right? I think they're about the same size to fit in the original holders, but not as large as the barrel ones.

True, but the Alkaline batteries and Macintosh PRAM batteries were Non-rechargable. And the 3.6 Mac batteries are lithium aren't they? I wouldn't want to use anything like that when the motherboard is forcing recharging current back through the battery.

My interest with using 3xAA NiCd batteries is that the original Barrel battery is really 3 small NiCd button cells in series wrapped in plastic, each providing 1.2v each for a total of 3.6v. AA NiCd's provide 1.2v (1.25v I think actually) each and recharge in a similar way, hooking 3 together might provide 3.6 volts in an easier to replace down the road setup, that is, if it will actually work. Could always try it I guess, I doubt it'd blow up.

That's why you use a diode with the alkaline batteries, to prevent the recharge 😀

The lithium one I linked is non rechargeable as well. Even without recharging they last years.

If you use the 4 pin external battery header, that doesn't recharge, and is in fact what I'd recommend you use anyway as its easier to replace a battery connected with a Berg header than one with wires soldered into the internal battery pads on the board.

You *could* use 3x AA NiCd cells connected to the internal battery solder pads, but given NiCd's tendency to leak, and given that even non rechargable batteries seem to last up to 5 years anyway, I suspect it might be more effort than its worth.

Even alkalines can leak so no matter what you do mount it either outside the case altogether or in a spot where it can't drip onto anything. The lithium one I linked is sealed quite well so I think the risk of leaks is fairly minimal (they're still stuck out of the way, just in case 😀 )

Markk wrote:

. . . . No need to wait for the soldering iron to heat up. 😀

Which is exactly why I bought one of these:

Weller 100/140w soldering gun. My favorite soldering device ever! I love this thing.

Sorry to open up an old thread, but I recently picked up a working Packard Bell 486SX/25 and I need to replace the barrel battery. Can anyone recommend what I should replace it with? How do I know if I have an external battery header?

So, after looking at my pictures above, I think the 3-pin connector near J28 could be an external battery header, but I can't find any documentation for the Packard Bell Legend 2000 MultiMedia machine. Nor do I know if I need to set a jumper to enable it.

Can anyone help? Would this work? I'm hesitant to put one of these NiCad barrels back in there.

http://www.atbatt.com/product/23832.asp?utm_s … CFehDMgodRyMAbQ