After searching for a replacement for this battery I finally found 1. Duracell 6v from Batteries +.


This battery sits under the alarm behind the 'bump' adjuster. Although a bit bigger it can be made to fit...lol

 

do you mean the location is on the passenger side of the cabin because i thought it was located in the trunk next to the antenna on my 93 xjs. thanks, Rick

 

Yup, that's the place. Right behind the right rear light. I believe the alarm changed somewhere in the '93s. Mine has three separate boxes. The alarm box which is bolted to the rear light bolts and 2 smaller boxes underneath that. 1 holds the 6v backup battery and the other has the adjustable 'bump' sensor.
They look like this above......1st is bump sensor, 2nd is the battery box

 

My '89 XJRS has it under the R/H seat. Factory interface loom and hardware. It would be an absolute pain to work on there but it is inoperable at the moment anyway. Battery was replaced with a unit from a radio control hobby store with very little drama.