del

jheronimus wrote:

1) can I try to start the system before replacing the battery? I'd like to know if it's working before I deal with it.

Yes, if the leakage has not affected anything yes and the board is working it should start up without issues.

jheronimus wrote:

2) do I really need to change the battery? Not sure what's it used for on a system like this besides the time/date/BIOS settings

Well, at the very least you should remove the leaking battery. If you can live with having to re-enter BIOS settings each time you power up, the system should work without the battery (some boards refuse to POST without battery, but I think that's mostly when an RTC chip is used).

jheronimus wrote:

3) is it doable? I don't have any soldering skills, but I have a friend with soldering iron. He can do this if I can show him what needs to be done and I can source the battery.

Removing the battery is a veary easy job. Just apply some heat to the joints and rock the battery a bit to crack the glue blob. It should pop right away (you can add fresh solder if you are having trouble with the joins). As for replacing it, the recommended thing to do is buy/build a non-rechargeable battery pack out of AA batteries or similar and connect it to the 4-pin external battery header located near the barrel (there are several threads here on how to do it). You could also replace it with a new barrel, but at some point it will leak again.

jheronimus wrote:

4) what should I use to clean the traces of the leakage?

As the battery electrolyte is alkaline, an acid substance such as vinegar or lemon juice can be used to neutralize the corrosion. Note that this won't fix damage if the corrosion has gone too deep, but I can't tell how much damage (if any) there is since the battery kind of blocks the view.

jheronimus wrote:

As for replacing it, the recommended thing to do is buy/build a non-rechargeable battery pack out of AA batteries or similar and connect it to the 4-pin external battery header located near the barrel (there are several threads here on how to do it).

Old motherboards with a NiCad rechargeable barrel battery usually trickle charge the battery when it is powered. When using non-rechargeables they will get charged causing them to heat up with the possibility that they catch fire or explode.
As the barrel batteries are 3.6V you can use a three battery AA or AAA wired battery holder and rechargeable batteries that will give 1.2V each adding up to the 3.6V like the original battery.

Regarding battery replacement, refer this site for some tips - http://pc-restorer.com/replacing-cmos-b ... n-old-pcs/
For older motherboards, I prefer an external battery connection.
I've used a 4x 1.5V battery "pack" on most of my 386 & 486 motherboards with no problems (non rechargeable).

Certainly remove that barrel of cancer asap and check for broken traces, treat the board with something to neutralize the acid like vinegar and soapy water so it doesn't rot on your later. Coin cells and even super caps of have been used a battery replacements so have fun 😀

Thanks a lot, guys! I'll test the motherboard tonight and will try to remove the barrel.

This is what I have done with one of my motherboards. A 486 board, that used to have a rechargeable barrel battery on it.

The battery are one of these:
http://www.ebay.com/sch/i.html?_from=R40&_trk … 2+Tabs&_sacat=0

If you know a guy that can solder...
http://www.ebay.co.uk/itm/2x-Ni-MH-80mAh-3-6V … sMAAMXQlgtS1goH

Also keeps it looking original

Ah, that was 2x - 1x ..
http://www.ebay.co.uk/itm/1x-Ni-MH-80mAh-3-6V … %3D151794194877

Even more original, and cheaper too, this one is NiCd rather than NiMH.
http://www.ebay.co.uk/itm/1x-Ni-Cd-60mAh-3-6V … %3D400985882789

Beginning to wonder though, all the one supplier, and so cheap compared to anyone else, are they going to be ok?

Recently I've been using Li-Ion 3.6V rechargeable barrel batteries (they look just like the original Ni-Mh batteries). They're slightly longer then the original barrel batteries, but fit just fine.

They look kind of like this: http://www.all-battery.com/primaryultrahighen … 0withwires.aspx

Can't find a link to exact ones I'm using... Anyway, the Li-Ion cells are less prone to leaking so there's little chance of those damaging your board. You can also use solderable 3.6v coin cell batteries like brostenen suggested, although they don't fit on all boards - or solder a vertical coin cell battery holder and use a CR2450 3.6v rechargable battery witch you can remove when the board is not in use.

Personally I prefer using a Li-Ion barrel batt - it's pretty easy to solder on and cheaper then the holder + CR2450.