I had to replace the batteries in my Easy Hitch.
http://www.etrailer.com/Hitch-Access...s/JE00600.html
The pair of them take four L41 button batteries.
The cost for one at London Drugs is $4.29 ( plus tax ).
I got four for $3.36 at Mountain Equipment Co-op ( including tax ). 75 cents each.
MEC doesn't carry every battery, but it's worth checking before you shop at your local drug store.
baglo