| Parameter | Value |
|---|---|
| Model | RS309-MM-EV |
| Brand | SINOFUSE (Sinofuse Electric, China) |
| Type | Round-tube bolt-connected power fuse, fast-acting (RS309 series) |
| Rated Voltage | DC 1000V |
| Rated Current | 50A–800A (series); contact us for this SKU’s available current rating |
| Breaking Capacity | DC 25kA |
| Protection Category | aBat (back-up battery fuse protection, per official spec) |
| Size Code | 5TC (per listing) |
| Body Material | Ceramic tube, copper terminals |
| Standards | IEC 60269 / JASO D622 / ISO 8820 / GB/T 31465; RoHS compliant |
| Applications | New-energy-vehicle BDU, EV high-voltage circuits, DC charging, industrial EV battery |
Note: Rated at DC 1000V / 25kA per the official SINOFUSE English specification. The original page title stated "Rated voltage DC 500V" — inconsistent with the manufacturer’s data and the 1000VDC sibling listing on this store; it is treated as a data-entry error and corrected here.
SINOFUSE RS309-MM-EV is a 1000V-class round-tube bolt-connected EV power fuse from the RS309 family, specified by the manufacturer for new-energy-vehicle battery disconnect units (BDU). It delivers a DC 25kA breaking capacity with the aBat back-up battery protection category — clearing high-energy faults fast while withstanding the vibration, shock and thermal cycling of vehicle and industrial battery installations.
The series covers 50A to 800A, making it suitable for the main circuit, power distribution and charging paths of EV battery systems, DC fast-charging equipment and industrial EV battery packs.
RS309-MM-EV sits alongside RS309-MD-EV (DC 500V, 20kA) in the SINOFUSE RS309 bolt-connected family and shares the same catalog platform as the EV315, SFM and EV8MKM vehicle fuses and the RS306 / RSZ307 / FGB wind-solar-storage fuses shown in the manufacturer’s catalog charts below.
Rated DC 1000V with DC 25kA breaking capacity — sized for the 800V-architecture battery packs and high-voltage DC buses used in modern EV BDU designs.
Official protection category aBat means it is engineered as a back-up fuse for battery circuits — coordinating with contactors and BMS disconnect logic to interrupt short-circuit energy before it damages the pack.
Alongside IEC 60269, ISO 8820 and GB/T 31465, RS309-MM-EV references JASO D622 — the Japanese automotive fuse standard used by Japanese OEM platforms and tier-1 BDU suppliers.
RS309 bolt-connected design (size code 5TC) gives a low-resistance, vibration-proof mounting for BDU busbars and high-current DC rails in vehicles and industrial battery racks.
One model family covers the medium-to-high current range, simplifying BOM, qualification and spares for EV battery, charging and industrial battery programs.
Supplied from Sinofuse Electric original production — China’s nationally recognized champion in new-energy-vehicle low-voltage fuses — with official datasheet, JASO/IEC/GB test references and RoHS compliance available.
SINOFUSE RS309-MM-EV is qualified against international vehicle-fuse standards (reference standards per official specification):
IEC 60269 — Low-voltage fuses (performance reference).
JASO D622 — Japanese road-vehicle fuse standard.
ISO 8820 — Road vehicles — Fuse-links (performance & environmental reliability).
GB/T 31465 — China road-vehicle fuse-link test standard.
RoHS — Restriction of hazardous substances compliant.
Official datasheet PDF and factory test reports are available on request.
Primary fuse position inside BDU / BDU+ for battery main circuits, per the official application scenario of RS309-MM-EV.
Overcurrent protection for battery systems, drive power systems, power conversion and on-board charging of new-energy vehicles.
Module- and cabinet-level protection in DC fast-charging and ultra-fast-charging systems at 1000V class.
Protection for industrial EV battery packs and high-voltage DC distribution — confirm rating selection for your fault conditions.
The official SINOFUSE English specification lists RS309-MM-EV as DC 1000V / 25kA, and the 1000VDC RS309-MM-EV sibling listing on this store matches. The original "DC 500V" title appears to be a data-entry error and has been corrected to the manufacturer’s rating here. If your purchased batch is marked differently on the nameplate, please note it in your order and we will confirm before shipping.
Both share the RS309 round-tube bolt-connected platform but target different voltage classes: MD-EV is rated DC 500V with 20kA breaking (e.g. the 125A–200A MD-EV SKU), while MM-EV is the DC 1000V / 25kA member of the family used in higher-voltage BDU and DC-bus positions.
This is a quote-based SKU and does not state a single current rating; the RS309-MM-EV series spans 50A to 800A. Tell us the current and voltage of your circuit and we will match the exact ordering part number for you.
"aBat" is the manufacturer’s designation for a back-up battery protection fuse: it is not intended to carry sustained overloads alone but to act as the final short-circuit back-up coordinated with the contactor / BMS disconnect in the battery circuit. Confirm the coordination with our engineers using the official curves.
Yes. We can supply SINOFUSE RS309-MM-EV samples, the official datasheet PDF, RoHS declarations and factory test reports, with OEM and volume pricing on request.
