BMW’s wireless Key Fob Charging feature, while convenient, requires leaving your key in the car, which isn’t always practical, especially for apartment dwellers without a garage. If you’re finding your BMW key fob range diminishing, indicating a low battery, and are seeking alternative key fob charging methods, you’re not alone. Many owners are exploring home-based solutions for key fob charging to maintain optimal operating range.
One promising avenue is inductive charging. Experimenting with an Adafruit Induction Charging Set reveals the potential of this approach. Inductive charging kits, similar in principle to some electric toothbrush chargers, can offer a way to replenish your key fob’s battery outside the vehicle. Initial tests show that placing the BMW key fob with the roundel facing the charging loop maximizes current draw, suggesting optimal alignment for efficient key fob charging.
These BMW key fobs typically utilize a Panasonic VL-2020 battery, a rechargeable coin cell with a 20mAh capacity and a standard charge current of just 1.5mA. This low charge current means that even with a basic inductive charger, a full key fob charging cycle should be achievable in a reasonable timeframe, well under 20 hours. While some anecdotal evidence points to toothbrush chargers working for key fob charging, further investigation into the in-car wireless charging coil design could offer valuable insights for optimizing DIY charging solutions and improve key fob battery life. Exploring the internal components of a factory BMW wireless charger might reveal further clues to refine aftermarket key fob charging techniques.
