Outback Power Batteries

If you're building an off-grid solar system, adding backup power to a grid-tied setup, or replacing an aging battery bank, you've probably come across OutBack Power batteries. The name gets mentioned a lot in solar circles, but with five product series and multiple chemistry types on offer, it's not obvious which one you actually need.

This guide covers the full EnergyCell lineup: what each series is, what it's designed for, which specs matter most, and how to match the right solar energy storage battery to your system type and usage habits.

What are OutBack Power Batteries?

OutBack Power is a US-based manufacturer of renewable energy equipment, including inverter/chargers, MPPT charge controllers, and batteries. Their battery line is called EnergyCell, and it covers five distinct series: standard AGM, Nano-Carbon AGM, float-service AGM, flooded lead-acid, and lithium.

What separates EnergyCell from a generic deep cycle battery for solar is native system integration. They're engineered to work directly with OutBack's own power electronics, connecting to the OPTICS RE monitoring platform and the MATE3 system display for real-time performance data. OutBack also makes purpose-built IBR racking enclosures sized specifically for these batteries.

EnergyCell Battery Series Explained

EnergyCell RE: Standard AGM for Off-Grid Systems

The EnergyCell RE is OutBack's baseline sealed AGM battery for residential or light-commercial off-grid solar. As a VRLA battery (Valve Regulated Lead Acid), it uses Absorbent Glass Mat separators — sealed, no watering required, and no meaningful gas output under normal operation.

Good fit for: off-grid homes and cabins that need a dependable off-grid solar battery for daily charge/discharge cycling.

EnergyCell NC: Nano-Carbon AGM for Partial State of Charge Operation

The EnergyCell NC (Nano-Carbon) is built on the same VRLA-AGM platform as the RE, but with a proprietary nano-carbon formula on the negative plates. That change has a real impact on how the battery handles imperfect solar charging.

Solar systems often can't fully recharge a battery every day — cloudy stretches, oversized loads, and seasonal variation mean a battery may sit in a partial state of charge (PSoC) at 50–80% for extended periods. Standard AGM batteries sulfate faster under those conditions. The NC is built specifically for PSoC operation, maintaining cycle life where a regular AGM would wear out early.

Good fit for: off-grid systems with variable solar input, self-consumption setups, and any installation where the battery won't reach 100% charge every cycle.

EnergyCell GH: Float-Service AGM for Grid-Tied Backup

The EnergyCell GH uses Thin Plate Pure Lead (TPPL) AGM technology. It's not designed for frequent deep cycling — it's designed for grid-tied backup, where the battery spends most of its life at or near full charge (float) and only activates during outages or peak-rate hours.

Its cycle life at 50% DOD is just 650 cycles, much lower than the RE or NC. For a backup battery that rarely discharges deeply, that number is largely irrelevant. What the GH offers instead is an 18-month shelf life and a 4-year warranty, the longest of any OutBack lead-acid model.

Good fit for: grid-tied or AC-coupled backup systems where the battery mostly floats and discharges deeply only a few times per year.

EnergyCell FLA: Flooded Lead Acid for High-Capacity Off-Grid

The EnergyCell FLA uses traditional flooded lead-acid technology. The cells are not sealed — they require regular watering with distilled water and equalization charges every 30 days (or every 14 days when routinely cycled below 50%).

Why choose this over sealed AGM? Cost and capacity. The FLA series includes a 2V / 1,400Ah cell that can be strung into very large battery banks for solar panels at a lower cost per amp-hour than any sealed alternative. For large off-grid installations where a maintenance routine is workable, FLA is a practical choice.

The 525FLA includes a PROeye electrolyte level indicator — an optical signal that turns clear when a cell needs water, taking the guesswork out of routine checks.

Good fit for: large off-grid systems where cost per amp-hour is the priority and regular maintenance is manageable.

EnergyCell 5: LiFePO4 Lithium for Scalable, Zero-Maintenance Systems

The EnergyCell 5 is OutBack Power's LiFePO4 deep cycle battery: a 48V / 100Ah (5kWh) stackable module for residential backup, off-grid solar, and small commercial applications.

Each module includes an integrated BMS that continuously monitors voltage, current, and temperature, plus an internal fire-extinguishing module. LiFePO4 chemistry is the most thermally stable of the common lithium types, and the EnergyCell 5 is rated IP65 for outdoor installation. Unlike the lead-acid options, it needs zero maintenance and carries a 10-year warranty.

You can stack three to eight modules per stack and expand to 24 modules total. The system auto-identifies how many modules are connected, which simplifies installation and removes one configuration step.

Good fit for: new builds where long service life, zero maintenance, and room to expand later are the priorities.

Full Series Comparison

Key Specs to Check Before You Buy

Capacity (Ah)

Amp-hours measure how much energy the battery holds. A 100Ah battery at 12V stores 1.2 kilowatt-hours. Capacity is usually rated at the C/20 rate (a 20-hour discharge). At faster discharge rates, usable capacity drops — check the discharge curve in the spec sheet if your system draws heavily or intermittently.

Depth of Discharge (DOD)

Battery depth of discharge (DOD) is how far you drain the battery per cycle. At 50% DOD, a 200Ah battery delivers 100Ah before you stop discharging. Deeper cycles mean more energy per use, but fewer total cycles over the battery's life. Most off-grid solar battery banks are sized to stay at or below 50% DOD to balance daily capacity against long-term cycle count.

Cycle Life

Battery cycle life is the number of full charge/discharge cycles a battery delivers before capacity falls to 80% of its original rating. At 50% DOD: RE = 1,800 cycles, NC = 2,600 cycles, GH = 650 cycles. Cycle life directly determines cost per kilowatt-hour over the battery's service life — often a more useful comparison than upfront price alone.

Round-Trip Efficiency

The percentage of energy you put in that you actually get back out. The NC series reaches 95%; standard AGM runs around 90%. That 5-point gap adds up significantly over years of daily cycling, especially in systems with high daily energy throughput.

Operating Temperature

All OutBack AGM batteries discharge down to -40°F, covering most North American climates. Charging is more sensitive: none of the AGM models should be charged below -10°F. Note that the GH has a tighter upper discharge limit (122°F) than the RE and NC (160°F), which matters for installs in hot or unventilated spaces.

Warranty

The RE and NC carry two-year full replacement warranties. The GH and 1400FLA cell carry four years. The EnergyCell 5 carries 10 years — in line with the longer expected lifespan of LiFePO4 chemistry.

Which OutBack Battery is Right for You?

Pick the Right Chemistry, Then Size the Bank

OutBack's EnergyCell lineup covers most common solar battery applications, with each series built for a specific use case. The RE and NC handle daily off-grid cycling. The GH is for grid-tied backup. The FLA covers large-capacity needs where maintenance is acceptable. The EnergyCell 5 is the right call when long service life and minimal intervention outweigh the higher upfront cost.

Start by matching the series to your system type — off-grid cycling, grid-tied standby, or high-capacity storage. Then size the bank by daily energy use, autonomy days, and target depth of discharge.

A1 SolarStore carries the full OutBack Power EnergyCell range, including IBR racking systems and the OutBack inverter/charger equipment these batteries are built to work with.

Frequently Asked Questions