Panasonic Rechargeable Battery
ALSO KNOWN AS: VL-2020/HFE
DIAMETER: 20.0mm THICKNESS: 2.0mm
Chemical Compound: Vanadium Pentoxide Lithium
Brand new Genuine Panasonic Rechargeable Battery VL2020
This is a replacement battery for the following Key fobs
BMW E39 and E46 keys (Commonly Known as Diamond Keys).
BMW E90/91/92/93 as well as many BMW key fobs from the early 2000's
The keys Recharge (using induction) when in the ignition but as with any rechargeable battery they are only good for about 1000 charges.
The keys are sealed and will Normally cost between £125 - £200 to purchase from BMW,
But with this battery you can simply replace the battery yourself, you will have to cut the key open with something sharp to replace the battery and then reseal the key. (there are many guides on how to do this on the internet).
This is the same Panasonic VL2020 batteries used by panasonic the only difference is with the pcb leg mounts.
BMW had a different shape pcb leg mount put on the there batteries (which you cant buy) but this just requires a little modification .