E 21000C | no support

Error image

The Stromer does not provide any support. If the battery is removed and reinserted, error E 21000C appears after 3 seconds. Switching the speed levels via the button ring works.

Cause

  1. Battery contact problem > Battery socket in battery compartment
  2. Wicket cable directly behind the battery base (in the bottom bracket area) defective
  3. Defective battery

Check / Test

  1. The sockets / plugs are magnetic and attract the smallest metal particles. Clean them with a lint-free cloth or compressed air. Do not use contact spray/grease or the 'all-purpose weapon WD40 Multifunction Smart Straw'.
  2. The wicket cable can only be checked after removing the battery compartment. You can see what a defective wicket looks like here.
  3. Test the battery in the service menu. How to do this here.

Updated on August 18, 2025
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