Transmitter batteries can lose their strength due to remote start, trunk release and other severe duty uses. They can drain in under 2 weeks, change is slow, but you slowly lose range.
Stock up on batteries! Line them up together, play dominoes with them in your spare time.
Give them to (or better yet, sell them) to your friends, amazing how people get spoiled by keyless entry systems and then when the battery goes dead, they will do anything for a battery. Put these batteries in your glove, in your jacket, in your room, have them handy!
Have you seen these at HOME D"""" MEGASTORES for $4.99 EACH?