[Chappers 71]

Had a low key battery warning light come up today, no worries I thought I'll use the spare until I can get a new battery. I put the spare in & the battery's also low on that one

I have done a search on how to open the key but the only vids I've come across are for comfort access & there's a little panel which pops out with the help of a screwdriver. Unfortunately my key doesn't have the panel on the back to pop out.
Anyone know how to open non comfort access key to change the battery?

[half Colin]

They're not designed to be opened as the battery recharges when you stick it in the ignition. So if you do open it and replace the battery make sure it's a rechargable one. I've heard they are soldered in as well.

[BMW_fun]

Also, do You use that key daily? If not, maybe You need to recharge it on a longer trip. If yes, then You will need a new battery.

[Chappers 71]

Have just spoken to my local dealer & it seems the battery's are rechargeable. & can't be replaced.
It does seem strange that I'm getting low battery for both keys, but then they are the same age.
BMW parts guy says book it in for a diagnostic, not for a £120 I'm not. He says I most likely need two new keys at £130 each..ouch.

[Chappers 71]

Used the car this evening put the key in & no low battery warning, tried the spare & that's now ok as well. Strange

[wolly440]

I regularly switch keys, say every month or two. If you haven't used your spare key for 3 0r 4 years, don't be supprised it's dead when you come to need it

[Chappers 71]

I do use the spare every couple of months or so.
Both keys are now good, no low key battery warnings

[BMW_fun]

It looks like they have charged