CMOS battery life expectancy on VXIpc-872B

[dannic]

Hello,

I work for Raytheon. We are supporting a subsystem that consists of a VXI chassis with a National Instruments VXIpc-872B as the controller. There are currently between 20 and 30 of these controllers that have been procured from National Instruments. Can you tell me what the battery life expectancy is for the Tadiran TL-5186 CMOS battery as used in the 872 VXIpc controller? We need to provide this information to our customer (and yours) for use in on-going maintenance support.

Thank You,

Dan Nichter

Daniel_J_Nichter@raytheon.com

[pBerg]

Howdy dannic,

Short answer: The short answer is that the CMOS battery has a shelf life of 10 years.

Longer answer: Motherboards draw power from the CMOS battery to retain BIOS settings, DateTime clock, etc, while the system is turned off. Having said that, the battery life depends upon how you use the VXI controller. If the VXI controller is turned on all the time, then the battery life will be extremely long because the CMOS battery isn't being used. However, if the VXI controller is turned off all the time, then the battery use will be much higher, and the battery life would be shorter.

Overall, the mean time between failures on CMOS batteries is also about 10 years, and that includes battery life and any other possible malfunctions. So the batteries should last for a long time, but it is too hard to specify further than that because of how dependent the battery life is on the system configuration and usage. If you would like to implement a battery replacement rotation program, you should be extremely safe replacing them every 5 years or so.

Here's an additional reference you might find handy, if not for posterity's sake:
KnowledgeBase 2JIGCU00: Information about the Lithium Battery in the VXIpc-770/870B Controllers

I hope this helps!


Message Edited by pBerg on 05-02-2008 01:08 PM

Message Edited by pBerg on 05-02-2008 01:09 PM