Car remote battery dead again!

Thread Starter

skippofemmy

Joined Mar 9, 2024
2
I have changed my car remote battery twice in the last 2 months, a completely strange scenario. I believe there's a short on the board, but I wonder how to identify the fault since a continuity test may not detect it. Any help please!!!

kfob.jpg
 

Dodgydave

Joined Jun 22, 2012
11,359
Better focused pics would be better, I would solder a 3V battery pack to the pcb and measure the current it takes, and how much it take when the button is pressed.
 

ThePanMan

Joined Mar 13, 2020
803
One of the issues I've seen with my key fob - not the same as a remote starter I guess - is that it spends a lot of time in my pocket. There's a lot of buildup of lint and a good measure of accumulated dirt after long periods of time of ownership. Your board might just require a good cleaning. Cleaning the contacts and the (assumed) carbonized rubber pads with isopropyl alcohol MIGHT make things better. But take care to handle it in a safe manor as you don't want to introduce electrostatic discharge which could ruin your remote. If it's going through batteries at an abnormally high rate then there's a parasitic draw on it somewhere.

One other possibility - I bought a bunch of coin cell batteries so I'd have them. Recently I had a fob go dead. It hasn't been that long since I changed the battery. So I got out one of the new batteries and put it in and it was dead as well. And it was stored in the plastic shipping package. If you get cheap batteries they probably won't last. It's possible you got a bad batch. I sure did when I ordered from Amazon.
 

ThePanMan

Joined Mar 13, 2020
803
That one button on the right looks a little dirty. I wonder if perhaps there has been some dirt infiltrate into the contacts, not creating enough of a current pathway to activate the circuit but potentially enough current to drain a battery in a few weeks. But that's just a guess.
 
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