As a pre-emptive measure before my 14-year old '99 E300TD is delivered to it's new owners, I decided to replace the twin Energizer #2520 batteries in each of my '99's key FOBs.

With the help of an O'Reilly Auto Parts counterman, I was shown the How-to of this battery replacement procedure. It takes a little doing to get in to the FOBs to replace these batteries, as well as some gentle placement of the batteries when re-installing.

Both of of my key FOB's batteries were still functioning, 14 years after new. One FOB was used exclusively for this period of time, but since the FOB is a tad intricate to get into to do the R&R, I thought it best to do the replacement of both FOBs while I have time to prepare the car for delivery.



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