Key fob battery sensitivity?

[KevCarver]

How sensitive are the key fobs to battery drain? My ‘19 Sport just passed 2 years (Got the anniversary email this week) and I intermittently get walk away lock weirdness. I popped the battery out and it measures 2.92 volts, 2.95 on spare fob. Spec’ed at 3v, brand new one is 3.4.
Random weirdness is sometimes not locking when I walk away, but not getting the fast beeps. It’s been winter, so I haven’t used the auto roll down much. Seems to have good range when I do.
Anyway, I’ve got a new battery in now, just wondering if I should buy another for the spare fob?

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[JT Si]

I had all kinds of issue with weirdness, beeping, not locking with no beeping, etc. When I had my key on my keychain with other keys. Even still when I carry it in my change pocket now if my phone is in the pocket it can block the fob signal.

Couldn't hurt to replace the battery but you may want to experiment with what metallic objects are near your key fob when you get out of the car.

 

[KevCarver]

Thanks for the reply. I literally have no other keys that I carry in my pocket. Park in the garage, so I don’t even need a front door key. Seems good with the new battery.
Anybody know if those testers on the parts store counters are any good? Or just there to sell batteries?

 

[PhilF]

When in doubt, replace. With the CR2032 batteries, I've had the best success with Maxell & Sony, made in Japan. The Duracell, made in China or Indonesia, not so much. Locally I see mostly primarily private-label, Duracell or Energizer. The Energizer can be made in many places, the Japanese ones are preferred. You can generally buy them on Amazon in strips of ten for about a buck each. They have a long storage life. The remotes tend to be somewhat fragile, if I'm going to take one apart to test the battery, for the dollar, I would rather just replace it.

 

[BriteBlue]

Over the years when a fob starts acting up I take out the battery and give it a firm wiping with a clean paper towel in order to assure a good electrical contact. This usually provides a few more weeks or months of service. I've read that batteries "off gas" and release a gas that may build up on it's surface. I don't know if that's significant, but wiping off the contact surfaces seems to buy some time.

About a week ago my other other car's fob was acting up. The battery measured 2.99V and a new one was a bit over 3V. So I wiped off the old battery & put it back in & now the fob can lock/unlock the car from inside the house. Big difference compared to before wiping.

 

[BriteBlue]

When in doubt, replace. With the CR2032 batteries, I've had the best success with Maxell & Sony, made in Japan. The Duracell, made in China or Indonesia, not so much. Locally I see mostly primarily private-label, Duracell or Energizer. The Energizer can be made in many places, the Japanese ones are preferred. You can generally buy them on Amazon in strips of ten for about a buck each. They have a long storage life.

I bought a strip of 5 Energizer cells from ebay a couple years ago. I looked up the date codes & they should have lasted longer, but one was dead last year & one this year. These were made in Japan. I did my research to make sure these were not fakes but apparently not all the cells were up to snuff.

At the time I bought them I noticed the Sony cells had a lower mAh rating than other brands.

FWIW, over the last year I've had 10 Duracell batteries leak. These were both AA and AAA cells that were used in clocks, phones, etc. All had 4-5 years shelf life left so I'm surprised they leaked. They were all purchased from Costco. Costco now sells a 10 pack of 2032 cells but I'm hesitant to try those.

 

[KevCarver]

I think it’s just the battery voltage at this point. I used it today without issues. It was an Energizer that was sitting in my toolbox for a few years. Maybe I’ll get another for the spare and not install it yet.
I saw a couple other threads pop up with even shorter battery life. Both fobs are pretty close to the car at home, but not close enough to open it.
I don’t know how fragile the fobs are to opening, but I understand plastic is plastic...??‍

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