Key Fob Battery Replacement

[Johnd]

Does anyone know of a place that will replace the battery in the key fobs? One of the Fobs for my ZHP is completely dead and the other one is now starting to go. I have the lock cover on the drivers door so I am afraid of getting locked out.

[John in VA]

Scott at https://www.bmwgm5.com/Key_Repair.htm

[az3579]

Scott at https://www.bmwgm5.com/Key_Repair.htm

The page you linked directly states in the first line:
"This is not a key fob battery replacement service! This is a key fob repair service for keys that no longer start the engine and remotes that no longer work."


Does anyone know of a place that will replace the battery in the key fobs? One of the Fobs for my ZHP is completely dead and the other one is now starting to go. I have the lock cover on the drivers door so I am afraid of getting locked out.

There are DIYs out there that show you how to replace the battery. Here is the one I had bookmarked for when I was going to do it, but haven't had to yet.
https://www.youcanic.com/guide/bmw-key-battery-replacement

And as far as getting locked out - you could just remove the cover to expose the keyhole.

[Johnd]

I just talked to Scott and he says the batteries never need to be replaced.. Has anyone else had to replace the battery?

[Vas]

How about just ordering a new key?

[az3579]

I just talked to Scott and he says the batteries never need to be replaced.. Has anyone else had to replace the battery?

I seriously doubt the batteries never need to be replaced. Just due to the nature of how batteries work, that alone says they will need to be replaced eventually. They do last a really long time though; the battery in my 2001 E39's fob is original and still works fine.

I would recommend removing that keyhole cover and testing both keys to make sure they open the car, as well as start the car. If that portion is working, then it's probably just your remote that's dead. As to whether it's the battery or the remote circuitry, who knows...


How about just ordering a new key?

That's a pretty expensive solution to a cheap problem.

[John in VA]

The page you linked directly states in the first line:
"This is not a key fob battery replacement service! This is a key fob repair service for keys that no longer start the engine and remotes that no longer work.".
I know. The point being, how did the OP determine that the fob needs a battery?

[Vas]

That's a pretty expensive solution to a cheap problem.

Part Number: 66126955748
Cost: $166

Not that bad actually

[Johnd]

The door lock works fine and both keys start the car. I resynced and got on of the fobs working but the one I never use still isn't working. I thought it might be the battery as this was the issue will my old 330 coupe and the dealer charged me $200 for a new key and the symptoms were similar

[cornercarver]

I seriously doubt the batteries never need to be replaced. Just due to the nature of how batteries work, that alone says they will need to be replaced eventually. They do last a really long time though; the battery in my 2001 E39's fob is original and still works fine.
The battery is rechargeable, and whenever it is in the ignition it charges, but even rechargeable batteries wear out. My 530's fob stopped working after a while... I was lazy and just used the key to unlock until I sold it, but there is a way to cut open the fob and replace the battery. There are a few YouTube videos on this.

[cornercarver]

I resynced and got on of the fobs working but the one I never use still isn't working.
This is your problem. If you don't use it, the key is never in the ignition and doesn't charge, so the battery eventually dies. Try using it for a week and see if that fixes it.

[az3579]

Part Number: 66126955748
Cost: $166

Not that bad actually

$166 is still a lot of money...


This is your problem. If you don't use it, the key is never in the ignition and doesn't charge, so the battery eventually dies. Try using it for a week and see if that fixes it.

Yeah, the fact that my touring sat for over 6 months before I bought it from the PO is why I didn't believe the seller when he said the key needs a new battery. Sure enough, after a week of regular use (30 minutes each way to/from work), the key charged up enough and the fob has been working fine consistently since, over a month now. It does take a while to build up a sufficient charge for the fob to work reliably after a key's been sitting for a long time though.

[pedro2u]

When I bought my vert, one of the keys was dead from the PO leaving it in his drawer for 9 years. Key wouldn't function well or charge with regular driving. And following advice here on the forum, I put the key in the ignition with the ignition on overnight and with a battery charger hooked up. Fully charged in the morning, Still didn't work right though, but was clued in about the resync procedure Chris mentioned below and all was solved

[pedro2u]

actually Johnd mentioned the resync

[pedro2u]

resync with link was in this link

http://www.zhpmafia.com/forums/showthread.php?21359-Recharging-Dead-Key-FOB&highlight=resync

See Scotts site

[Johnd]

I was hoping to find a company that did this as I don't want to mess around with it

[az3579]

When I bought my vert, one of the keys was dead from the PO leaving it in his drawer for 9 years. Key wouldn't function well or charge with regular driving. And following advice here on the forum, I put the key in the ignition with the ignition on overnight and with a battery charger hooked up. Fully charged in the morning, Still didn't work right though, but was clued in about the resync procedure Chris mentioned below and all was solved

So the resync solved your dead battery issue?

[Johnd]

What happened is the wife switch my good key with the bad key on the key ring - apparently if you try using the bad key it screws up the good key and it needs to get synced. So my good key is working again for the most part - still a little flakey (lights didn't flash a few times). The other key definitely doesn't work and if you don't sync them both at the same time the keys will get out of sync. So I want to find a place to send the bad key to have the battery changed.

[wstr75]

A previous owner had split open the single key fob I received and apparently messed around with the innards. I sent the key to Scott and he made it new again. I also bought a second key fob and can't remember if I bought it from Scott or elsewhere. I did the synchronization steps and life has been good ever since.

[pedro2u]

So the resync solved your dead battery issue?

Leaving the key in the ignition overnight may or may not have been necessary. But can't hurt. At least it was charged. Since I tried the overnight charge trick before I even attempted the resync, I can't be sure which one was the real fix

[Johnd]

Just ordered a new key through the dealer for $169. I'll see if that fixes it. I also found out when ordering the key my registration expired last May - so I had to get that fixed too...

[Mless5]

Just keep in mind that new key may not work right away, you need to leave it in ignition for 15-30 minutes first.