Question about replacing old Compaq CMOS battery

Forums › Desktop computing › Question about replacing old Compaq CMOS battery

kiwibloke09

41 posts

Geek
+1 received by user: 6

#322637 6-Sep-2025 18:03

Gidday everyone,

I have a old Compaq Deskpro 5133, the CMOS battery has recently died and I am getting these error messages at boot 1155-System Board Comm Port Address Assignment Conflict, 601-Diskette Controller Error & 611-Primary Floppy Port Address Assignment Conflict. The CMOS battery is soldiered on to the motherboard but I have been told that i can use a external CMOS battery by switching the CMOS jumper from internal to external then connecting the external CMOS battery to the pins. This is what the pins look like: [PIN1] [GAP] [PIN2] [PIN3]. I was wondering where I could buy one of these and how to connect them to the pins. I found this on PB Tech (https://www.pbtech.co.nz/product/SEVOEM0259/CR2032-2032-Battery-2Pin-2-WIRE-CABLE-Plug-for-Lap) does it look right?

Cheers

Samuel

P.S Go the All Blacks!!

giddy

Dynamic

4015 posts

Uber Geek
+1 received by user: 1850

ID Verified

Trusted

Lifetime subscriber

#3412126 7-Sep-2025 09:23

Wow. These machines are a real blast from the past!

I was doing some googling around this and have seen in more than one post that the external battery is 4.5v. Here is one example that also shows what appears to be an original external battery with the connector and pinout.

Amazon.com: COMPAQ DeskPro 4000 5166MMX CMOS Battery : Electronics

This post shows someone used a 4x 1.5v AA battery holder with only 3x batteries in it to make a 'good enough' battery for the job. Consider going down this route.

external 4.5v battery polarity (compaq deskpro 2000 5166) \ VOGONS

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

kiwibloke09

41 posts

Geek
+1 received by user: 6

#3412151 7-Sep-2025 11:13

Thanks for the reply and the links

I did ask ChatGPT just to see what it would say and it did tell me about the AA Battery method but I just thought it was AI being stupid but I guess it actually is a real method.

Thanks again for the help

Samuel

giddy

kiwibloke09

41 posts

Geek
+1 received by user: 6

#3412153 7-Sep-2025 11:18

I have found this one off Jaycar (https://www.jaycar.co.nz/4-x-aaa-side-by-side/p/PH9268). Do you think this is a good one?

giddy

Dynamic

4015 posts

Uber Geek
+1 received by user: 1850

ID Verified

Trusted

Lifetime subscriber

#3412172 7-Sep-2025 13:45

kiwibloke09:

I have found this one off Jaycar (https://www.jaycar.co.nz/4-x-aaa-side-by-side/p/PH9268). Do you think this is a good one?

Yes that would be fine. Search their site for PH9274 for an even better option.

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

kiwibloke09

41 posts

Geek
+1 received by user: 6

#3412185 7-Sep-2025 15:13

This One? (https://www.jaycar.co.nz/3-x-aa-side-by-side-flat-battery-holder/p/PH9274)

Also the one off Jaycar doesn't have the plug looking thing like this bloke (https://www.vogons.org/viewtopic.php?t=91320). Do you know how to connect those wires to the pins on the motherboard?

giddy

Dynamic

4015 posts

Uber Geek
+1 received by user: 1850

ID Verified

Trusted

Lifetime subscriber

#3412273 8-Sep-2025 08:20

kiwibloke09:

This One? (https://www.jaycar.co.nz/3-x-aa-side-by-side-flat-battery-holder/p/PH9274)

Also the one off Jaycar doesn't have the plug looking thing like this bloke (https://www.vogons.org/viewtopic.php?t=91320). Do you know how to connect those wires to the pins on the motherboard?

Yes, that's the one.

Ask the guys at Jaycar if they have the connectors like the ones shown on the Vogons web site. I don't know what they are called. A connector with wires can likely be pulled from an older computer.

A little bit of soldering will be involved, I expect. An enthusiastic Geekzoner may be able to help with that, or a professional electronics repairer like this Geekzone user Spong on Geekzone (profile) (he fixed my Tivo unit a few years ago) or Philips Electronics in Penrose.

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

Quic Broadband

Move to New Zealand's best fibre broadband service (affiliate link). Free setup code: R587125ERQ6VE. Note that to use Quic Broadband you must be comfortable with configuring your own router.

kiwibloke09

41 posts

Geek
+1 received by user: 6

#3412353 8-Sep-2025 10:11

Alright thanks a lot mate for all the help. I might go to one of those free repair cafe events at the mangere bridge library, see if they can do it.

giddy

nztim

4012 posts

Uber Geek
+1 received by user: 2710

ID Verified

Trusted

TEAMnetwork

Subscriber

#3412354 8-Sep-2025 10:17

OMG Deskpro, this is a huge blast from the past

One of the most bulletproof PCs ever made, never failed, only made obsolete

Any views expressed on these forums are my own and don't necessarily reflect those of my employer.

Lias

5655 posts

Uber Geek
+1 received by user: 3978

ID Verified

Trusted

Lifetime subscriber

#3412502 8-Sep-2025 14:26

Wow that takes me back to my early IT career lol. Thanks for the blast from the past.

I'm a geek, a gamer, a dad, a Quic user, and an IT Professional. I have a full rack home lab, size 15 feet, an epic beard and Asperger's. I'm a bit of a Cypherpunk, who believes information wants to be free and the Net interprets censorship as damage and routes around it. If you use my Quic signup you can also use the code R570394EKGIZ8 for free setup. Opinions are my own and not the views of my employer.