PSA: watch out when recharging keys

[Bdc101]

I have a Battery Tender Power Plus with 3 amp output. I was trying to recharge my keys and left it in the garage overnight with the key in "on" position but engine not running.



I woke up in the morning and the car lights up, but only barely. It won't start. My DMM says 11.4 volts.



I turned the car off and left the charger on it. Apparently the car takes more than 3 amps with the key on and the motor off. This is actually the big battery tender too -- the standard version is only 1.25A.



I'm using the terminals in the engine bay, if that matters.



Just your friendly PSA.

[wpoll]

Yep - the car will draw WAY more than 3 amps with the key on but engine off...

Bet you wish you'd seen this thread before, which outlines how to charge your flat key fob battery with a Samsung Gear wireless watch charger...

https://xoutpost.com/bmw-sav-forums/...w-key-fob.html

[Bdc101]

I tried that with my wireless phone chargers but it won't work.


No harm no foul though. I just turned the key off and it started after an hour or so on the trickle charger.

[wpoll]

Nah, wireless phone chargers don't work - just the Gear watch charger. Different wireless charging system.

[andrewwynn]

Qi chargers use very different frequencies. The key is a very basic charging method that is apparently compatible with the watch charger


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