About this replacement
Thomson Sesame 250 — 24V Ni-MH Replacement Battery (114200)
This is a 24V 700mAh Ni-MH battery for the Thomson Sesame 250 automatic door operator. It fits the backup power circuit in the door controller, keeping the unit operational during mains failure. OEM part numbers covered: 114200, 114165, 114166, 510062, and 114201.
- Sesame 250 controller fit: The Sesame 250 uses a dedicated 24V backup rail with a specific connector and charge management circuit. This replacement matches that voltage and physical footprint — 104 × 44.3 × 21mm — so it seats correctly in the controller housing without modification.
- Bench tested on actual hardware: We cycled this battery through the Sesame 250 controller's charge circuit and confirmed the BMS accepted the charge handshake without fault codes. We also verified the backup circuit engaged correctly on simulated mains loss.
- Post-installation power-fail test: After fitting this battery, manually trigger a power-fail simulation during a low-traffic window. Automatic door backup batteries must complete a full door cycle under load at installation — do not assume the battery is ready without a live test.
Door controller losing programming after a power outage
The Sesame 250 stores door timing, force limits, and safety sensor profiles in volatile RAM. That RAM is backed by this 24V battery. When the battery depletes below the controller's hold voltage — typically around 21V — the RAM drops power and the configuration is lost. Replacing the battery alone does not restore the programming; you need to re-enter the door parameters after the new battery has charged fully. Allow at least 24 hours of charge before running a configuration write.
Battery backup not activating when mains power fails
If the door stays locked or unresponsive during a mains failure, the backup circuit may not be receiving adequate voltage from the battery. A depleted or end-of-life Ni-MH cell can sit above the controller's low-battery warning threshold at rest, but collapse under the motor-start load. Check the battery's open-circuit voltage — it should read at or above 25.2V on a fully charged 24V Ni-MH pack. If it reads below 24V at rest, the battery needs replacement, not recharging.