Key fob battery keeps dying

codys21 · 11-17-2022, 03:49 PM

So I've had my 2015 F83 for just under 2 years. I needed to first replace my key fob battery about 6 months ago so I bought a pack of Rayovac batteries and replaced it. All was well. About a month ago I had to replace it again and now it needs to be replaced again. It's so weak that it won't automatically unlock my doors while the fob is in my bag and I need to hold the key against the steering column to start the car.

It is my DD, though I only drive it 3 or 4 times per week (hybrid work policy). When at home, the fob is about 15 feet from my car, through one door/layer of drywall.

I don't know why the battery would be dying so quickly and why it seems to be dying more quickly now than it did when I first got the car.

Any ideas?

HarryTee · 11-17-2022, 04:53 PM

Have you got 2 fobs? Both behave similarly? If you haven't, try both and if only one consumes batteries at a faster rate, it'd then be the fob's problem.

N1rve · 11-17-2022, 04:56 PM

Quote:

Originally Posted by codys21

So I've had my 2015 F83 for just under 2 years. I needed to first replace my key fob battery about 6 months ago so I bought a pack of Rayovac batteries and replaced it. All was well. About a month ago I had to replace it again and now it needs to be replaced again. It's so weak that it won't automatically unlock my doors while the fob is in my bag and I need to hold the key against the steering column to start the car.

It is my DD, though I only drive it 3 or 4 times per week (hybrid work policy). When at home, the fob is about 15 feet from my car, through one door/layer of drywall.

I don't know why the battery would be dying so quickly and why it seems to be dying more quickly now than it did when I first got the car.

Any ideas?

Try a Energizer Lithium. My experience with Rayvac is that it doesn't seem to last as long as an Enegizer or a Duracell.

DocL · 11-17-2022, 06:26 PM

I use Duracell and have only had to change it once in two years. Rayovac are crummy batteries.

ShopVac · 11-18-2022, 06:32 AM

Was told once that keeping the key in the car wears down the battery...not sure if it's true, but if it's a back and forth communication to the car, may be something to it.

That being said...I leave mine on the passenger seat while it sits in the garage and do tend to go through a fair amount myself. I'm also one to roll up and down the windows with the fob.

Ended up buying a 20 pack off Amazon for $10, so no worries. Just keep one in the glove box for emergency.

bagekko · 11-18-2022, 12:38 PM

I also believe keys stored outside the car but within comfort access proximity drains the battery.

I no longer buy cheap button cells and there are many fake name brands on Amazon & eBay.

Been buying big packs of 2032s at Costco lately for ring alarm devices, red dots, and my older BMW FOBS.

This is in my Amazon subscribe and save every 6 months for my newer BMWs.

https://www.amazon.com/dp/B00O35ULSY...tail_page?th=1

Quote:

Originally Posted by ShopVac

Was told once that keeping the key in the car wears down the battery...not sure if it's true, but if it's a back and forth communication to the car, may be something to it.

That being said...I leave mine on the passenger seat while it sits in the garage and do tend to go through a fair amount myself. I'm also one to roll up and down the windows with the fob.

Ended up buying a 20 pack off Amazon for $10, so no worries. Just keep one in the glove box for emergency.

Redacre · 11-18-2022, 04:25 PM

I went through this a few weeks ago and it turned out to be the batteries I had just weren't that good. I can't even remember what brand they were, but I bought some duracells and presto, no more low battery dash warning.

NORAGRETS · 11-18-2022, 04:33 PM

Quote:

Originally Posted by N1rve

Quote:

Originally Posted by codys21

So I've had my 2015 F83 for just under 2 years. I needed to first replace my key fob battery about 6 months ago so I bought a pack of Rayovac batteries and replaced it. All was well. About a month ago I had to replace it again and now it needs to be replaced again. It's so weak that it won't automatically unlock my doors while the fob is in my bag and I need to hold the key against the steering column to start the car.

It is my DD, though I only drive it 3 or 4 times per week (hybrid work policy). When at home, the fob is about 15 feet from my car, through one door/layer of drywall.

I don't know why the battery would be dying so quickly and why it seems to be dying more quickly now than it did when I first got the car.

Any ideas?

Try a Energizer Lithium. My experience with Rayvac is that it doesn't seem to last as long as an Enegizer or a Duracell.

Buy a better battery

N44RP · 11-18-2022, 05:47 PM

I’ve left my key in my car for a month at a time with no issues to those saying it’ll drain the key fob

Not in my experience at least

hC1001 · 11-22-2022, 12:43 PM

I leave my keyfobs in a faraday box. Stops any signals from the fobs. The battery last more than a year... I change the battery after a year just in case.

DocL · 11-22-2022, 01:16 PM

Quote:

Originally Posted by hC1001

I leave my keyfobs in a faraday box. Stops any signals from the fobs. The battery last more than a year... I change the battery after a year just in case.

That goes well with the tinfoil hat too lol.

N1rve · 11-22-2022, 03:17 PM

Quote:

Originally Posted by DocL

That goes well with the tinfoil hat too lol.

That guy lives in Brooklyn NY, I wouldn't blame him.

11-17-2022, 03:49 PM	#1
codys21 Private First Class 60 Rep 134 Posts Drives: 2015 F83 Join Date: Nov 2020 Location: Iowa iTrader: (0)	Key fob battery keeps dying So I've had my 2015 F83 for just under 2 years. I needed to first replace my key fob battery about 6 months ago so I bought a pack of Rayovac batteries and replaced it. All was well. About a month ago I had to replace it again and now it needs to be replaced again. It's so weak that it won't automatically unlock my doors while the fob is in my bag and I need to hold the key against the steering column to start the car. It is my DD, though I only drive it 3 or 4 times per week (hybrid work policy). When at home, the fob is about 15 feet from my car, through one door/layer of drywall. I don't know why the battery would be dying so quickly and why it seems to be dying more quickly now than it did when I first got the car. Any ideas?
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11-17-2022, 04:53 PM	#2
HarryTee Lieutenant 214 Rep 497 Posts Drives: 2020 M4CP & 2017 440i GC Join Date: Jan 2020 Location: UK iTrader: (0)	Have you got 2 fobs? Both behave similarly? If you haven't, try both and if only one consumes batteries at a faster rate, it'd then be the fob's problem.
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11-17-2022, 06:26 PM	#4
DocL Captain 1927 Rep 867 Posts Drives: 2018 M3 Join Date: Jan 2019 Location: Delray Beach iTrader: (2)	I use Duracell and have only had to change it once in two years. Rayovac are crummy batteries. __________________ 2018 F80 M3. YMB/BLK. ZCP. Three Pedals. "Education will never be as expensive as ignorance."
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11-18-2022, 06:32 AM	#5
ShopVac Not willing to take advice 4044 Rep 1,527 Posts Drives: F82 M4 - 6MT Join Date: May 2010 Location: PA iTrader: (1) Garage List 2018 BMW M4 [9.83] 2023 Genesis GV70 [6.50] 2018 Abarth 124 Spider [10.00] 2014 Audi S4 [6.50]	Was told once that keeping the key in the car wears down the battery...not sure if it's true, but if it's a back and forth communication to the car, may be something to it. That being said...I leave mine on the passenger seat while it sits in the garage and do tend to go through a fair amount myself. I'm also one to roll up and down the windows with the fob. Ended up buying a 20 pack off Amazon for $10, so no worries. Just keep one in the glove box for emergency. __________________ Proud owner of 4 Turbos and 1 Supercharger
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11-18-2022, 04:25 PM	#7
Redacre 6 Cylinders 3 Ways 368 Rep 458 Posts Drives: M5, 911, Macan Join Date: Sep 2014 Location: FL iTrader: (10) Garage List 2019 BMW M5 [0.00] 2015 BMW M4 [0.00] 2015 Porsche Macan ... [0.00] 1986 Porsche Carrera [0.00]	I went through this a few weeks ago and it turned out to be the batteries I had just weren't that good. I can't even remember what brand they were, but I bought some duracells and presto, no more low battery dash warning.
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11-18-2022, 05:47 PM	#9
N44RP Second Lieutenant 70 Rep 299 Posts Drives: M3 Join Date: Mar 2018 Location: East iTrader: (0)	I’ve left my key in my car for a month at a time with no issues to those saying it’ll drain the key fob Not in my experience at least
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11-22-2022, 12:43 PM	#10
hC1001 Captain 591 Rep 984 Posts Drives: E36 M3, F80 M3 Join Date: Nov 2019 Location: Brooklyn, NY iTrader: (4)	I leave my keyfobs in a faraday box. Stops any signals from the fobs. The battery last more than a year... I change the battery after a year just in case.
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