Changing the Battery in a Volkswagen Jetta Key — DIY for Just $1

One fine morning my Jetta greeted me with a message telling me to replace the battery in the key. So I started looking — not for some cheap Chinese CR2032 knockoff, but for an original.

An OEM CR2032 runs about $6 each. Why pay more? I went to the supermarket and bought a two-pack of Panasonic cells in blister packaging for about $1.50 — by the way, those are also made in Indonesia, just like the OEM ones.

In the end I ended up with two authentic batteries for keys (for part 5K0-837-202-AJ) without overpaying for the VAG-branded packaging.

It’s simple to replace: pop off the small cover under the VW logo on the key and swap the coin cell.

Two quick, factual notes about VW keys

1. Many Volkswagen key fobs use a CR2032 coin battery (while some older fobs use CR1632). If your fob looks like the modern flip/3-button style, CR2032 is the common cell.
2. Volkswagen key fobs typically contain a transponder (immobilizer) chip — commonly ID48 / Megamos in many modern VW remotes — which the car needs to recognize before it will start. That means while you can replace the battery yourself, the transponder chip itself must remain intact and properly paired with the car. The part number 5K0-837-202-AJ is a common 3-button remote that uses a CR2032 and an ID48-type transponder.