4V 450Ah Carbon Foam Firefly Oasis

$856.70 $825.50

4V 450Ah Carbon Foam AGM battery with exceptional performance under Partial State of Charge

Product Description

Pre-orders available only at this time.

Resilient Storage
Firefly’s award-winning technology improves upon lead-acid batteries with unmatched performance and lifespan in deep charge and discharge cycling. The patented Microcell carbon foam design solves the leading causes of failure in lead-acid batteries by resisting sulfation and corrosion, making it a more reliable and longer lasting battery than any other lead-acid battery on the market. Carbon Foam shares most of Lithium-Ions benefits over traditional Lead-Acid batteries for less than half the price.

The Firefly Oasis boasts the best in market for recovery from extended storage in a discharged state while still enjoying a faster charging time than leading AGM competition. It can be operated for an extended period of time in Partial State of Charge without loss in capacity. Its excellent recovery from storage makes it an ideal battery for occasional excursions off-grid or for powering cabins which are only used for part of the year.

The thermal conductivity of carbon foam creates a more uniform temperature distribution throughout the battery. Compared to a traditional cell, the Firefly cell produces less localized corrosion and wear while utilizing active materials more effectively overall. This gives Firefly Oasis the longest lasting life of any other batteries in their chemistry type and can operate under extreme temperatures.

Best in Price
The long lifespan of the Firefly Oasis batteries mean every dollar stretches for the most cost-effective energy storage available. These batteries can live up 3-4 times longer than regular VRLA batteries for the same price and require no maintenance. With a rating of 90-95% efficiency and an unlimited depth of discharge, the Firefly Oasis ensures users get the most out of their purchases.

The Firefly Oasis batteries are best in their class for Kilowatt-Hour capacity, and because of the 100% DOD of the 4V 450Ah, this powerful battery can compete with batteries twice its size with an average 50% DOD. This Firefly Oasis grants the lowest cost of ownership for every Kilowatt-Hour in your portable power systems.

Power Banking

The 4V 450Ah batteries trade voltage for exceptional Amp-Hour capabilities. The huge capacity is perfect for off-grid power banks where high loads require affordable wattage. Leading deep-cycle batteries which enjoy 12V ratings rarely exceed 100 Amp-hours, giving them a maximum of 1.2 Kilowatts. By contrast, a single Firefly Oasis 4V 450Ah battery has a capacity of 1.8 Kilowatts.

Combine 4V batteries in a series to produce the necessary voltage for the load while enjoying a huge advantage in capacity. Or connect the Firefly Oasis batteries in parallel to create a massive bank of Amp-Hour capacity which far exceeds any competition in its price range.

Power Bank Series Wiring Example

Revolutionary Recharge

The Carbon Foam solution of the Firefly Oasis series offers exceptional recharge capabilities, able to charge to 100% of its rated Amp-hour capacity even after weeks of battery abuse. This battery is able to operate for long periods of time in Partial State of Charge (PSOC) while still enjoying the most of its long life and high capacity.

The 4V 450Ah is the perfect solution for off-grid, mobile, or marine homes which experience especially shady or rainy conditions. Fill up the batteries when you can for however long you can and they’ll supply the maximum amount of power possible thanks to its deep DOD and PSOC capabilities.

The Firefly Oasis batteries also have considerably shorter charging times than competing AGM batteries, able to drop the charging time down by 30%. Fast charging allows these batteries to get the most out of solar charging in unpredictable weather.

Firefly Oasis vs Brand X
Learn more at Coastal Climate Control

The Firefly Oasis is already the star lead-acid battery for mariners worldwide. In testing done by Rodd Collins of Compass Marine for Practical Sailor, the Firefly Oasis was the only AGM battery able to return to more than full capacity after a month of abuse in partial state of charge cycling.

Firefly Oasis PSOC Recharging
Learn more in the Practical Sailor

Another field test by Nigel Calder proved similar results after an even longer period of time.

“In preliminary testing I worked the Firefly batteries hard in a real-world (onboard, while cruising off the west coast of Scotland) partial state of charge operation. The goal was to minimize engine run times and optimize electrical system performance in an ‘off-the-grid’ situation with limited recharging opportunities. The kind of operating regime I followed spells death for most lead-acid batteries. In contrast, after two months of intensive cycling, the Firefly batteries tested out with 100% of the capacity with which they started. These are encouraging results which, if substantiated over longer periods of time, represent a ‘game changer’ in terms of lead-acid technology and boat electrical systems design. I look forward to collecting more data.”

–Nigel Calder

Learn More in Professional BoatBuilder

Firefly Oasis batteries are suitable for uses with RVs and trailers, marine applications, defense, mining, transportation and vehicles, and off-grid housing.

Additional Information

Battery Type

VRLA AGM Gel with Microcell Carbon Foam

Nominal Capacity

450 Ah (1.8 kWh) @ 20 Hour

Nominal Voltage


Max Charge Current


Max Charge Voltage


Internal Resistance

1.1 mΩ

Depth of Discharge

100% DOD

Partial State of Charge Cycling Efficiency

Ah: >97%; Wh: >90%

Operational Temperature

-20⁰C to 50⁰C (-4⁰F to 122⁰F)

Storage Temperature

-30⁰C to 60⁰C (-22⁰F to 140⁰F)

Shelf Life @25⁰C (77⁰F)

2 Years

Self Discharge

< 3% per Month

Life Cycle

4925 Cycles at 50% DOD; 1475 Cycles at 80% DOD


10.16 x 6.85 x 17.24" (25.8 x 17.4 x 43.8 cm)


97 lbs (44 kg)

Terminal Configuration

3/8 – 16 UNC




6 Years


Firefly International Energy Co.

Spec Sheet
Charging Recommendations
Battery Brochure