Glad you got it sorted.
One thing to be aware of is the little cr2032’s are bad for fooling people into thinking they are ok when actually they are dead. Whilst basically dead they can still show 3v on a multimeter.
When you put the battery under load the voltage can drop to nothing.
I load test mine using an old remote fob which is of a style that makes it easy to probe the battery with a meter whilst it’s in the fob, and also easily press and hold the lock or unlock button at the same time to put the battery under a suitable load.
Good new cells will barely have a 0.1v voltage drop under load.
Bad ones can go from 3v to 0.01v under load.
Help programming key FOB
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boosted_diesel
- Posts: 663
- Joined: Mon Jan 08, 2024 10:41 pm
- Vehicle: Mondeo/duratec he/1999cc/2002
Re: Help programming key FOB
Precisely what I experienced when testing them !
They start at 3V, and even the multimeter drains them fast (cheap multimeters have lower internal resistance)
I'll drill holes on the FOB. Good idea
They start at 3V, and even the multimeter drains them fast (cheap multimeters have lower internal resistance)
I'll drill holes on the FOB. Good idea
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boosted_diesel
- Posts: 663
- Joined: Mon Jan 08, 2024 10:41 pm
- Vehicle: Mondeo/duratec he/1999cc/2002
Re: Help programming key FOB
Yeah they are deceptive.
I built a cell tester from an old landrover remote lock fob.
I just soldered a wire to power and one to the ground contacts of the cell holder on the pcb. Then I crimped red size female spade connectors to the end of the wires. Standard meter probes fit into the female spades perfectly. So I can read voltage then press the button and get the under load voltage within seconds and without dropping everything five times lol.
I built a cell tester from an old landrover remote lock fob.
I just soldered a wire to power and one to the ground contacts of the cell holder on the pcb. Then I crimped red size female spade connectors to the end of the wires. Standard meter probes fit into the female spades perfectly. So I can read voltage then press the button and get the under load voltage within seconds and without dropping everything five times lol.