FIRMAN · Expansion battery
B104201
Expand your backup power with the FIRMAN Zero-E Battery expansion pack. Adding 1,040Wh of capacity to your FIRMAN Zero-E Energy Storage System, this slide-lock battery connects effortlessly—just slide it into place until
$499.99
$849.99
Direct price snapshot
Visual spec gallery
Core specifications, simplified.
1,040Wh
Rated battery capacity
Manufacturer runtime
Runtime varies by load
Operating volume
Silent battery power
Fuel tank
No combustion fuel
28.6
Unit weight
15.4x10.6x8.3
Unit dimensions
- Warranty
- 3-year warranty
- Certifications
- CARB · CETL · EPA
- Availability
- Available
Starting
Push-button power
Power quality
See specifications
Safety
Low-oil status listed below
Electrical
See full specifications
100W × USB-C PD Watts · 100W × USB-C PD Watts · Yes × USB-C PD In&Out 100W
Official product gallery
Product views and FIRMAN infographics.
These manufacturer images may include dimensions, control-panel callouts, included equipment, safety features, and common use cases. Scroll sideways to view the complete set available for this model.











Complete specifications
Every official field, organized.
The technical fields below come from FIRMAN’s model-specific specification file. Product photos and infographics come from the official product gallery. Confirm current documentation before purchase.
Manufacturer overview
Expand your backup power with the FIRMAN Zero-E Battery expansion pack. Adding 1,040Wh of capacity to your FIRMAN Zero-E Energy Storage System, this slide-lock battery connects effortlessly—just slide it into place until it clicks. Stack up to 10 batteries for a total capacity of 11,440Wh, giving you serious energy for extended outages or off-grid use. Charge it independently or as part of your Zero-E system. An onboard 100W USB-C port powers laptops, tablets, phones, drones, and more. Built with Lithium Iron Phosphate technology, the Zero-E Battery delivers safe, reliable performance with over 4,000 charge cycles. Whether you're preparing for emergencies or powering adventures, this expansion pack keeps you going longer. The FIRMAN Zero-E Energy Storage System delivers clean, emission-free power wherever you need it—perfect for homes, apartments, RVs, and vehicles. With 4,000 starting watts and 2,000 running watts, the Zero-E can power small to medium appliances, electronics, and essential devices. Featuring advanced EPS (Emergency Power Supply) pass-through technology, the Zero-E automatically backs up your fridge, modem, sump pump, or security system during an outage—switching to battery power in milliseconds. Its Lithium Iron Phosphate battery ensures safe operation, 4,000+ charge cycles, and long-term reliability. Need more runtime? Easily expand with slide-on Zero-E batteries—up to 10 add-ons for a total of 11,440Wh capacity. Power up your devices with six 120V outlets, a TT-30R RV outlet, four USB-A ports, two 100W USB-C ports, a 12V cigarette outlet, a 12V DC port, and a Qi wireless charger. Recharge the Zero-E your way: from a standard wall outlet, your vehicle’s 12V socket, or up to 400W of solar input. Whether you're preparing for emergencies or living off-grid, the Zero-E is your all-in-one portable power solution.
Certifications
- cETLus (UL2743)
- Yes
- UN38.3
- Yes
- FCC SDOC
- Yes
- FCC ID
- No
- IC ID
- No
- DOE
- No
- CEC
- No
- SDS
- Yes
- ROHS
- Yes
Main Unit
- Rated Capacity
- 1040Wh
- Cycle Life
- >4000 complete cycles to 80% capacity
- Storage Temperature
- -20 ~ 40 °C (-4 ~104 °F)
- Discharging Temperature
- -20 ~ 40 °C (-4 ~104 °F)
- Charging Temperature
- 0 ~ 40 °C (32 ~104 °F)
- Shelf Life
- 12 Month
Input
- AC Charging Watts
- 400W
- MPPT Watts
- 400W
- Car Charging Watts
- 240W
- USB-C PD Watts
- 100W
Output
- USB-C PD Watts
- 100W
Control Panel
- LED Level Display
- Yes
- Main Power Switch
- Yes
- USB-C PD In&Out 100W
- Yes
- XT60 DC Input
- 1
- Expansion Pack Male Connector
- Yes
- Expansion Pack Female Connector
- Yes
- XT60 Cover
- Yes
Frame
- Pull Rod
- Yes
- Color
- Black
Battery Pack&BMS
- Battery Cell Spec
- LI-FUN 25Ah 3.2V
- Battery Type
- LFP
- Pack Configuration
- 13S1P
- Cooling
- NA
- Rated Charging Current
- 35A
- Rated Discharging Current
- 65A
- Overcurrent Protection
- Yes
- Temperature Protection
- Yes
- Short Circuit Protection
- Yes
- Balance Management
- Yes
Packaging
- UPC Code
- 840876105016
- Carton Dimensions
- 19.7x15x11.4
- Carton Weight
- 31.5
- Product Dimensions
- 15.4x10.6x8.3
- Product Weight
- 28.6
Best-fit uses
- Camping
- Home Projects
- Power Outage
- Tailgate
- Work
Standout features
- See the complete specifications and official gallery above.
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