JoulesThief
Posts: 2576
Joined: Mon Oct 05, 2015 2:01 pm

Re: Car on Charger in Key Fob Dead - trifecta

Mon Jun 18, 2018 10:43 am

msvphoto wrote:Anyone know for sure what battery to get for the fob? I would prefer not to open it up before buying spare batteries. The owner's manual says go to dealer and calls it a "20mm battery" which is not super helpful, but to be fair the manual at least does show how to replace it.

Stocking up on spares before this crisis seems like a good idea. Over 90% of our car's use is with my wife's key which lives in her purse. My key hangs out on our key holder in the house, mostly as a spare, since the car is her daily driver. Swapping her key's battery before it dies might be a good thing also.

20 25.... 20mm wide, probably 2.5mm thick, VS 20 32 20mm wide, 3.2mm think. It takes a 2025
2015 e-Golf SEL
2015 Passat TDI SEL
2014 Touareg TDI LUX

Full spectrum VW owner, life is too short to wait to drive for a recharge.

BKipp
Posts: 4
Joined: Mon Jun 11, 2018 9:03 pm

Re: Car on Charger in Key Fob Dead - trifecta

Mon Jun 18, 2018 8:07 pm

Energizer CR-2032 [Lithium] - worked perfectly. Bought at Target.
—2017 VW EGolf key fob

JoulesThief
Posts: 2576
Joined: Mon Oct 05, 2015 2:01 pm

Re: Car on Charger in Key Fob Dead - trifecta

Mon Jun 18, 2018 8:39 pm

BKipp wrote:Energizer CR-2032 [Lithium] - worked perfectly. Bought at Target.
—2017 VW EGolf key fob
And it's the wrong battery for this application... read the owners manual, next time. Don't damage the springs tension by using too large a battery for the application, those Key Fobs are $250 to $300 each to replace. A very expensive mistake.
2015 e-Golf SEL
2015 Passat TDI SEL
2014 Touareg TDI LUX

Full spectrum VW owner, life is too short to wait to drive for a recharge.

msvphoto
Posts: 196
Joined: Mon Nov 20, 2017 12:30 pm

Re: Car on Charger in Key Fob Dead - trifecta

Tue Jun 19, 2018 11:36 am

JoulesThief wrote:
BKipp wrote:Energizer CR-2032 [Lithium] - worked perfectly. Bought at Target.
—2017 VW EGolf key fob
And it's the wrong battery for this application... read the owners manual, next time. Don't damage the springs tension by using too large a battery for the application, those Key Fobs are $250 to $300 each to replace. A very expensive mistake.
That's the problem. The Owner's Manual states "20mm battery" with no reference to thickness. You are right, the number indicates size. According to what I found searching is that the 2025 and 2032 are regarded as interchangeable with the 2035 having slightly higher capacity. I wouldn't be too concerned about the contact spring being deformed by a 7 tenth of a mm difference (that really isn't much), but to be safe if a fob gets a 2032 installed it should probably stay that way and not go back to a 2025.

Anyway, glad to get a definitive on this since the Owner's Manual is so vague.
2015 e-Golf SEL my wife's daily, shared on weekends
2000 BMW 540iT my daily and our range extender
1986 Audi 4000 quattro "the cockroach" my alternate daily
1983 Audi Ur Quattro "the garage queen" looks pretty and appreciates daily

GdB
Posts: 11
Joined: Fri Aug 23, 2019 1:59 pm

Re: Car on Charger in Key Fob Dead - trifecta

Tue Oct 26, 2021 2:58 pm

I used a 2032 for awhile until it didn't. Tried replacing with new 2032 on my only KeyFOB and it would not work. I was not able to use my e-golf (2nd car anyway) until I realized it works with a 2025 cell. Really need to get a spare KeyFOB before this 2032 damaged one dies.
2016 e-Golf SE (after Sept 2019?)
2019 Kona Electric SEL

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