Fob battery replaced and still getting the low battery warning

When I was in parts I changed lots of fob batteries as most people were too timid to do it and would rather have someone else break them so as to have somebody to blame. I always asked how many times the fobs were dropped. Why? Commonly the battery clip or holder has partially or pretty much completely come loose from the tiny bit of solder holding it on and of course that leads to problems like in this thread. I typically told customers that first so they were ready for it when I showed them how it was cracked loose or broke.

Fobs work the exact same way they always have but just more complicated. Battery is not all that can be wrong there. The bracket holding it can crack to lower power as the circuit not working as well. Dropping fob can easily crack the no lead solder used now that gives so many problems. The antenna can damage too both in car and fob to complicate issues. Bad antenna in fob will act exactly like low battery and give the same message. Even your fingers getting in there messing with battery can corrode the contacts to not work right even if they look perfect, a mark of low volt circuits. I have one so finicky you have to spin the battery a bit to change position and contact, then it works fine until unused for several hours, then you have to do it again. Brand new name brand battery in it. I could coat the contacts with grease to stop that but too lazy so far.

So many never think of all the simple things that can go wrong there.

YES. Loose contacts are another one. They can be showing you the contact has cracked the solder again to be loose or the contact just gets loose from dropping the fob. Be careful rebending the contacts, common to break the solder again doing it because the lead free solder now used is so brittle.

I mentioned corrosion above, it may not be visible at all. I often sand contacts with #600 sandpaper and then lightly coat with grease to stop air getting to them. Because I live in a high humidity area that kind of invisible corrosion can drive you nuts when your remotes don't work. I have one to get it working I have to pop apart and simply spin the battery and it goes back to working right for maybe another month. I need to grease coat that one but haven't yet. Here you even have to do a flashlight or it quits working in a couple days, grease on contacts and no more trouble. Ridiculous.

Scar(r)y indeed.............