Image Map Image Map
Results 1 to 6 of 6

Thread: IBM PS/2 L40 SX Laptop Internal Batteries

  1. #1

    Default IBM PS/2 L40 SX Laptop Internal Batteries

    Greetings All !!

    I went to replace the CMOS battery in my IBM PS/2 L40SX Laptop only to discover that it actually has 2 separate batteries internally. It has one 3V Lithium battery and one 3.6v NiCd battery ? I have never seen any computer or laptop with 2 internal batteries like this. Can someone explain why there is 2 ? I am going to replace them both but would like to know what each does. I know one is for CMOS Clock backup but what's the other one for ?

    The 3V Lithium is very common, as I can purchase it online but, the other 3.6V NiCd is not. I am having a hard time finding a replacement. Anyone have a link to purchase this 3.6 NiCd battery ?

    Thank you !!

  2. #2
    Join Date
    Feb 2011
    Location
    NorthWest England (East Pondia)
    Posts
    2,350
    Blog Entries
    10

    Default

    The probably backs up the config. I assume this is in effect a MicroChannel machine so it has a config somewhere. Many NiCad are no longer made. You may be able to substitute NiMh..

    https://en.wikipedia.org/wiki/Nickel...admium_battery
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

  3. #3
    Join Date
    Oct 2008
    Location
    Kamloops, BC, Canada
    Posts
    5,934
    Blog Entries
    44

    Default

    Typically the 3.6v Ni-CD would hold the ram or CPU alive for a few minutes during a hibernation or sleep mode battery swap and the rest of the time the computer keeps it topped up.
    These days it's better to remove the battery because of how prone they are to leaking and not many of us still need to do live battery swaps.
    [Need something to waste time on? Click here to visit my YouTube channel CelGenStudios]
    --------------------------------------------------------------------------------------------
    [No time for videos? Click here to visit my Twitter feed @CelGenStudios]

    = Excellent space heater

  4. #4
    Join Date
    Feb 2017
    Location
    Guildford, U.K.
    Posts
    317

    Default

    Like most portable computers it will have two batteries, the 3V one to retain the RTC/CMOS config data and the other (no longer recommended) for when there's no mains supply at hand. Forget about the latter, just take your mains transformer everywhere, if "going mobile".

    What "we" know about the L40SX is here:
    http://ps-2.kev009.com/ohlandl/8543/8543.html

    Cheers,
    Tim

  5. #5

    Default

    Thank you guys !! WBST - thank you for the link. I seen the diagram an it makes sense now. I replaced the backup battery and it's storing the RTC and CMOS settings just fine now. I will pull the standby battery out (to prevent leakage) and will not replace it.

    Thanks, again all !!

  6. #6
    Join Date
    Feb 2017
    Location
    Guildford, U.K.
    Posts
    317

    Default

    Do check out Peter's ("Don" Peter Wendt's) suggestion to gut the battery pack and replace the innards with modern equivalents. It'll look pukka and do its job.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •