2XER18505M 3.6V 7Ah Siren Battery Pack
2XER18505M 3.6V 7Ah Li-SOCl₂ Siren Battery Pack. Equipment-Matched Connectors and Twin-Pack Kits Available.
2XER18505M 3.6V 7Ah Li-SOCl₂ Siren Battery Pack. Equipment-Matched Connectors and Twin-Pack Kits Available.
SUNJ ENERGY provides configurable 2XER18505M lithium cell packs for wireless sirens and security alarm systems. Each assembly uses two SUNJ ER18505M spiral-type Li-SOCl₂ primary cells. The standard 1S2P version supplies 3.6V nominal output and 7000 mAh nominal capacity, while OEM-style variants can keep the two cell circuits separately routed through a device-specific four-wire connector or cable adapter.
Compatibility note: This product is intended for replacement evaluation in Visonic MCS-720B, MCS-740 and SR-740 PG2 sirens, as well as DSC/Tyco PG9901 and PG9911 applications. Original equipment may use two battery packs and a cable adapter. The connector, pinout, polarity and wiring architecture must be verified before ordering.
A wireless siren spends most of its service life in low-current standby, but the sounder and strobe require substantially more power during an alarm. The spiral-type ER18505M is designed for this combination of long-term standby and higher operating current. A correctly configured two-cell assembly provides additional capacity, reliable pulse support and an equipment-ready connection for scheduled battery replacement.
The proposed SUNJ configuration includes:
● Two SUNJ ER18505M spiral-type Li-SOCl₂ primary cells
● 3.6V nominal output and 7000 mAh nominal capacity for the validated 1S2P version
● Internal parallel output or separately routed cell leads based on the approved sample
● Red/black stranded copper-wire harness with customizable lead length
● Device-specific keyed connector for Visonic-style or DSC/Tyco-style interfaces
● Heat-shrink insulation and mechanical retention/Spot welding
● Custom identification label and production traceability options
● Optional twin-pack kit with a device-specific cable adapter
| Option | Battery Arrangement | Output Interface |
| Standard single pack | 2 × ER18505M, internal 1S2P | Two-wire output; connector customizable |
| Visonic-style evaluation pack | Two cells with separately routed lead pairs or approved wiring | Two keyed 2-position interfaces; four leads |
| DSC/Tyco-style evaluation pack | Two cells with separately routed lead pairs or approved wiring | Keyed 4-position interface; four leads |
| Twin-pack kit | 2 × complete 2XER18505M modules | Device-specific dual-battery cable adapter |
Configuration note: The connector descriptions above are provisional interface categories, not confirmed connector manufacturer part numbers. Final housings, terminals and pin assignments are matched to an approved sample.
| Item | Specification |
| Battery chemistry | Lithium Thionyl Chloride, Li-SOCl₂ |
| Battery type | Non-rechargeable primary battery |
| Cell model and quantity | 2 × SUNJ ER18505M |
| Cell construction | Spiral type |
| Nominal voltage | 3.6V |
| Nominal capacity | 7000 mAh for the validated 1S2P version |
| Nominal energy | 25.2 Wh |
| Standard pack configuration | 1S2P; independent cell lead-out available |
| Cell discharge current | 500 mA max continuous / 1000 mA max available pulse |
| Calculated 1S2P capability | Up to 1000 mA continuous / 2000 mA pulse, subject to assembly validation |
| Approximate pack dimensions | 51 × 38 × 19 mm, excluding wires and connector |
| Connector | Device-specific keyed connector, customizable |
| Wire configuration | Two-wire or four-wire output, application-dependent |
| Wire gauge | 24–26 AWG stranded copper wire, customizable |
| Lead length | Approximately 50 mm standard, customizable |
| Cell operating temperature | -55℃ to +80℃ |
| Assembly method | Heat-shrink insulation and mechanical retention/Spot welding |
Specification note: The 1S2P assembly values are calculated from matched cells. Final pack current rating, connector, pinout, dimensions and wiring are based on an approved sample and application testing. Pulse-current conditions must be confirmed against the actual load profile.
For siren systems requiring two battery modules, SUNJ offers a twin-pack kit consisting of two complete 2XER18505M battery packs connected through a device-specific parallel adapter harness. Each pack remains an independent 3.6 V / 7 Ah module, while the complete parallel-connected kit provides a combined nominal capacity of 14 Ah.
| Specification | Twin-Pack Kit |
| Battery configuration | 2 × complete 2XER18505M battery packs |
| Total cell quantity | 4 × SUNJ ER18505M cells |
| Cell chemistry | Lithium Thionyl Chloride (Li-SOCl2) |
| Cell construction | Spiral type, non-rechargeable |
| Electrical configuration | Two 1S2P modules connected in parallel |
| Nominal voltage | 3.6 V |
| Capacity per battery pack | 7 Ah |
| Combined nominal capacity | 14 Ah |
| Combined nominal energy | 50.4 Wh |
| Connection system | Device-specific dual-pack adapter harness |
| Final connector | Customizable according to equipment requirements |
| Compatible equipment | Selected Visonic, DSC and Tyco wireless siren systems |
Specification note: Connector type, pinout, polarity and internal wiring must be verified against the original battery assembly or equipment requirements before ordering.
● Visonic MCS-720B and MCS-740 wireless outdoor sirens
● Visonic SR-740 PG2 PowerG outdoor sirens
● DSC/Tyco PG9901 and PG9911 wireless sirens
● Other wireless sounder, strobe and alarm/security devices using 3.6V ER18505M battery assemblies
Reference identifiers: 2XER18505M, 2ER18505M, DSC 2XER18505M, Tyco 2XER18505M, Visonic 2XER18505M, Fanso 103-304742, 239-304893, CS-VPX740BT and CS-DSG990BT
Compatibility note: Compatibility must be confirmed by the exact equipment model, original battery label, number of battery packs, connector housing, pinout, polarity and cable-adapter arrangement. MCS-720 and MCS-720B are different models and must not be treated as interchangeable references.
SUNJ ENERGY can supply a standard two-wire 3.6V 7Ah pack, an OEM-style four-wire assembly or a complete twin-pack kit for wireless sirens and other security equipment.
● Matched ER18505M cells and application-specific pack configuration
● Internal parallel wiring or independent cell lead-out
● Connector housing, terminals, pinout and polarity matching
● Custom wire length, wire gauge and lead arrangement
● Twin-pack cable adapter and device-specific harness development
● Heat-shrink insulation, mechanical retention and spot welding
● Custom labels, part numbers, packaging, prototype production and volume manufacturing
Request a sample or engineering review: Send us the equipment model, original battery label or part number, clear photos of every connector, lead length, available pinout information and whether the device uses one or two battery packs. We will review the cell arrangement, wiring, polarity, connector interface and cable adapter before preparing a sample.
It identifies an assembly containing two ER18505M lithium thionyl chloride primary cells. Depending on the equipment, the cells may be internally connected in parallel or separately routed through a four-wire connector and cable adapter.
No. A general-purpose 3.6V 7Ah version can use an internal 1S2P connection, but some original siren assemblies keep the two cells independently wired. The existing pack and connector must be checked before production.
It is intended for replacement evaluation against equivalent 2XER18505M assemblies. The original label, pack dimensions, wire count, connector, pinout, polarity and equipment model must be verified before ordering.
Original configurations may use four independent ER18505M cells assembled as two wrapped battery packs and connected through a cable adapter. The exact device revision and existing battery arrangement should be checked before replacement.
No. ER18505M is a non-rechargeable lithium thionyl chloride primary cell and must not be charged.
Yes. These components can be configured according to an approved sample, confirmed pinout and the electrical and mechanical requirements of the equipment.
SUNJ ENERGY is an independent battery manufacturer and is not affiliated with or endorsed by Visonic, Johnson Controls, DSC, Tyco, EVE or FANSO. All third-party trademarks, equipment models and part numbers are used solely for product identification and compatibility reference.
