286 CMOS battery replacement \ VOGONS

286 CMOS battery replacement

Topic actions

First post, by Hamby

Posted on 2019-05-30, 22:21

Hamby Offline

Rank Oldbie

Rank: Oldbie
Posts: 507
Joined: 2018-01-20, 11:12

Just took a look yesterday at the 286 motherboard I have sitting in the closet waiting for me to build a system around it, and I saw the telltale green "mold" of acid buildup on its barrel CMOS battery. Not a lot, as yet, and I don't think it's damaged the motherboard. But I obviously need to replace it.

Does anyone know of a (preferably US based) online electronics supplier from whom I could possibly buy a replacement?
More importantly, what can I replace the barrel battery with?

Reply 1 of 6, by MMaximus

Posted on 2019-05-30, 22:31

MMaximus Offline

Rank Oldbie

Rank: Oldbie
Posts: 890
Joined: 2014-03-30, 20:28
Location: FR

Does it have an external battery connector? It might be easier to connect an external battery pack to it.

Hard Disk Sounds

Reply 2 of 6, by Caluser2000

Posted on 2019-05-30, 22:46

Caluser2000 Offline

Rank l33t

Rank: l33t
Posts: 3672
Joined: 2014-10-21, 05:34
Location: NOO ZEELUND

Have a look on the board for BAT EXT header. Here's all you need to know about battery replacement. http://pc-restorer.com/replacing-cmos-batteries-in-old-pcs/

There's a glitch in the matrix.
A founding member of the 286 appreciation society.
Apparently 32-bit is dead and nobody likes P4s.
Of course, as always, I'm open to correction...😉

Reply 3 of 6, by Hamby

Posted on 2019-05-31, 19:42

Hamby Offline

Rank Oldbie

Rank: Oldbie
Posts: 507
Joined: 2018-01-20, 11:12

I pulled the board out today, and examined the battery under a magnifier.
Both sides had signs of corrosion, but I could see no signs of corrosion or damage on the motherboard.
I cleaned both sides with Coke using a Q-Tip (I forgot to get white vinegar this morning).
I then wiggled it back and forth until it broke off. I'll desolder the pins when I put a new battery in.
After, I cleaned the area under it with Coke, then cleaned it again with alcohol on a Q-Tip, then used a dry Q-Tip to dry that up.

Now to figure out what kind of battery it takes, buy one and install it.

Probably not the proper way to deal with it, but I'm new at this.

The attachment 20190531_135649.jpg is no longer available

The attachment 20190531_135659.jpg is no longer available

Reply 4 of 6, by Unknown_K

Posted on 2019-05-31, 19:51

Unknown_K Offline

Rank Oldbie

Rank: Oldbie
Posts: 1423
Joined: 2013-04-22, 18:59
Location: Youngstown, OH USA

I just solder in a coin battery holder with a diode inline (use heatshrink tubing on the diode so it doesn't short to anything) that will keep the board from charging it. Hot glue (same thing they used on the original barrel battery) will keep it all in place.

Collector of old computers, hardware, and software

Reply 5 of 6, by Predator99

Posted on 2019-05-31, 20:18

Predator99 Offline

Rank l33t

Rank: l33t
Posts: 2054
Joined: 2016-12-28, 19:09

Most likely the 4-Pin header on the bottom right of your 1st photo is for the external battery. Check with a mutlimeter if you are unsure. No need to solder anything.

Reply 6 of 6, by Hamby

Posted on 2019-05-31, 21:12

Hamby Offline

Rank Oldbie

Rank: Oldbie
Posts: 507
Joined: 2018-01-20, 11:12

Predator99 wrote:
Most likely the 4-Pin header on the bottom right of your 1st photo is for the external battery. Check with a mutlimeter if you are unsure. No need to solder anything.

cool, I'll check on that. Would make me feel a lot more comfortable.

Go to top of page Go to top of page

Back to General Old Hardware