New battery charging rules
Since 24 June 2025, emergency lighting has to stop charging its battery when the cells are too hot or too cold. Z10 products have worked that way since 2019.
What changed
BS EN 61347-2-7 covers the control gear inside self-contained emergency luminaires. Its latest version (BS EN 61347-2-7:2012+A2:2022) says the battery must not charge when the cell temperature is below or above the limits the battery's maker declares. The temperature control can sit in the battery, in its protection device or in the control gear.
The battery also needs protection against over-discharge, overcurrent and overcharging, and where two or more cells are in series, each cell's voltage is monitored separately. 24 June 2025 was the date the earlier versions were withdrawn, so products certified to them had to be updated by then (BSI).
How Z10 products charge
We were ahead of the game: since 2019, Z10 products have been designed with a 3-wire battery management system (BMS) that stops charging when it needs to, for safe operation. We design the control gear and the lithium-ion battery together.
- Temperature protection keeps the battery away from high and low temperatures.
- Charged to 80%, to improve the battery's lifetime, and topped up again from 79%: no constant trickle charge, and low standby power (0.5W).
- Over-current and deep discharge protection: the charging current is limited.
- Tested around the clock: in our factory, batteries run 24/7 at three different temperature ranges.
Every Z10 luminaire and conversion module has up to a 5 year warranty on the luminaire and battery, once registered within 6 months of purchase.
