About this replacement
Delta Dore 6416222 / Tyxal+ Series — 3.6V Li-SOCl2 Replacement Battery (WILPA2529C)
This is a 3.6V lithium thionyl chloride cell rated at 29000mAh, replacing the WILPA2529C in Delta Dore alarm and siren backup applications. It fits the 6416222, Bat CS 8000-SI-SEFIO3 Tyxal+, BP CS 8000 Tyxal+, and BPX bloc pile sirene among others. Li-SOCl2 chemistry holds voltage flat across long standby periods — the right match for a device that may sit on float charge for years between outages.
- Tyxal+ platform compatibility: The 6416222, BP CS 8000, and siren bloc pile units all run on the same 3.6V single-cell rail with a shared connector footprint. They expect the flat discharge curve that Li-SOCl2 delivers — a lithium-ion cell at the same voltage would confuse the panel's charge management circuit.
- Bench tested on actual hardware: We loaded this cell against the Tyxal+ panel's BMS and confirmed the passivation layer cleared within the first draw cycle. Voltage stabilised at 3.6V and the BMS accepted the cell without reporting a fault.
- Post-install float period: Do not run a zone or siren test in the first 24–48 hours after fitting this cell. The panel's charge circuit needs time to fully condition the new cell before its internal monitoring will report an accurate state. Testing too early produces a false low-battery flag.
Why the Tyxal+ panel reports low battery hours after a fresh cell is fitted
Li-SOCl2 cells form a passivation layer on the lithium anode during storage. When the panel first draws current, internal resistance is briefly elevated — the BMS sees a voltage dip and logs it as a low-battery event. This is not a fault with the cell. After one or two shallow discharge cycles the passivation layer breaks down, internal resistance drops, and the panel's voltage reading stabilises. Allow 24–48 hours on float before trusting any panel battery status indication.
Alarm losing programming during a mains outage after new battery fitted
If the panel loses its zone configuration during a power cut shortly after a battery swap, the cell has not yet been accepted by the backup circuit. Some Tyxal+ panels require a conditioning period before the battery rail is treated as a valid supply. The fix is to restore mains power, leave the system powered for 48 hours, and confirm the panel's battery indicator reads normal before the next outage. After that conditioning window, the backup circuit will hold programming through a mains interruption.