Hello, this is my first post, and im glad I can help with this... Recently I purchased a EP91 here in the Dominican Republic (they are getting popular around here, with left hand steering conversion). The thing is, I noticed my remote was also functioning strange, sometimes did not work at all. So I called in my rotary powertool to the rescue and with a smal disc I opened the case, and discovered that it doesnt work with RF, but with IR, then tried it again and from a distance of 6 ± 7 feet I can open the doors. The battery is held in place by a thin plate soldered to the back of it. Mine is working fine so no need to replace. I also made a hole in the front-left side of the remote so the IR LED can send the signal with ease. To put it together use Epoxy glue and with a little craftmanship you can leave it looking as "new", or at least you tried! ill post pics when I find my camera cable...