Sodium-ion battery, 3 days of autonomy (4 at most) — fits inside the VIAPREVENT IA unit
Ref. VIA_ECLAIRAGE_PUBLIC
Sodium-ion battery kit with 220 V charger built into the unit. 3 days of autonomy, safety margin included (battery ageing, cold); 4 days at most (240 Wh ÷ 2.5 W = 96 h). Fast recharging while the 220 V public lighting is on. Deep cold: the battery discharges down to −40 °C and charges down to −20 °C; below that, charging is suspended and the unit runs on its reserve (about 3 days) until the temperature rises again. 220 V charger: −30 °C to +70 °C.