After new car battery fitted getting Charge battery key fob

[TX1]

As per title, had car battery replaced today and now getting the message " Charge battery key fob " doing it with both key, mechanic said might need a long run.
Bit of a coincidence as did not have the message before the new car battery was installed, any ideas guys ?

[PistonHead007]

Funnily enough it always helps to start by doing what it tells you and only then look further if the problem doesn't go away.

[TX1]

Does a battery on a 2006 e92 always need registering and recoding ? Am finding conflicting information online and I know for a fact the mechanic did none of these things as I asked him if he done so, did not push the fact as was unsure if they always needed those couple of things done.

[Mr Tidy]

I'm pretty sure E9* keys charge inductively when the car is being driven.

Some people have had some success sitting them next to Oral B toothbrush chargers (other brands are available) but I haven't tried it myself.

Replacing the rechargeable battery in the key requires a bit of surgery to cut the case apart.

[TX1]

Battery was fine until I changed the car battery, was fine this morning, car battery changed this afternoon and instantly got the message when I went to pick it up, spare is the same. So my suspicion is not the key fob that is faulty and needs charging as even the spare is giving the same message.

[E-bmw]

So you don't think it is possible that they both need charging then?

[axel1990chp]

Swap them both out first port of call mate! That’s the easiest job out the way! I had my battery swapped on my E61 a few months back - was registered and coded by my local bmw indie, not had any problems with keys etc.

Is it “Occams Razor” the term for this?

ETA: if it persists I’m pretty sure any approved BMW garage can register the battery for you! Pretty quickly!

[TX1]

This morning started the car and no warning came on, went on a run swapped keys and both fine, so basically battery overnight sorted itself.

[g3org3y]

TX1 said:

This morning started the car and no warning came on, went on a run swapped keys and both fine, so basically battery overnight sorted itself.

Actually I had similar recently with the 630i.

Was sitting a few weeks while the I sorted the headlight. Battery level must have dropped to a level as the clock went blank. Chucked it on the trickle. Next morning gave me exactly the same key fob warning as you mentioned (which I thought odd). Drove the car to work. When I got there, fob out and then back in - no warning and nothing since.

Battery levels cause funny warnings on these cars, very sensitive!

[TX1]

Key fob keys/battery was changed a couple of years back, just in case anyone needs to change them it is a very staright forward swap and plenty of guides on youtube.
This is the item I bought https://www.ebay.co.uk/itm/332081662506 an easy and cheap fix.