Chemistry

Lithium Iron Phosphate (LFP) represents a lithium-ion battery chemistry that surpasses Nickel Manganese Cobalt Oxide (NMC) chemistry, commonly used in solar batteries, in several key areas. LFP offers benefits such as a longer projected lifespan, the ability to support deeper depth of discharge (up to 100%), and a broader range of operating temperatures. Additionally, LFP batteries avoid the use of nickel and cobalt, resources sometimes associated with ethical mining concerns, and they pose minimal risk of fires due to thermal runaway. These strengths position LFP as the leading lithium-ion chemistry for residential solar batteries, highlighting the Franklin aPower as a forefront technology in this field.

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Available Energy/Discharge Limits

Usable capacity quantifies the amount of energy a battery can safely release without compromising its longevity. Due to its LFP chemistry, the aPower can be fully discharged without affecting its lifespan, providing a usable capacity of 13.6 kWh.

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Energy Generation

The power output of a battery determines the amount of electricity it can supply over a given period and thus influences how many devices or systems it can support simultaneously. An individual aPower unit can deliver a peak output of 10 kW for up to 10 seconds, and it can sustain a continuous output of 5 kW.

For instance, starting a 4-ton air conditioning unit usually requires a 3.8 kW surge, while its operation typically consumes around 1.5 kW per hour.

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Two-Way Energy Efficiency

Roundtrip efficiency assesses the proportion of electricity that a battery system can return to your home from the total energy it initially stores. In AC-coupled battery setups like Franklin Home Power, efficiency reaches approximately 90% due to the need for current inversion both when charging and discharging the battery. Given this, the aPower’s round-trip efficiency of 89% aligns closely with other comparable battery systems.

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Approaches to Work

The FHP system offers three operational modes to suit different energy management needs:

• Backup mode: This mode provides power to your home systems and keeps your solar setup functional during grid outages.

• Self-consumption mode: In this mode, the system prioritizes storing and utilizing electricity from your solar panels, minimizing grid reliance by charging the battery solely with solar energy.

• Time-of-use mode: Similar to self-consumption mode, this mode also allows the battery to charge using grid electricity during off-peak hours, providing additional flexibility and savings.

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Warranty

Today's lithium-ion batteries generally come with warranties ensuring that they will retain at least 70% of their original capacity after a decade of use. Franklin's aPower battery offers a 12-year warranty or coverage up to 43 megawatt hours (MWh) of energy throughput, depending on which milestone is reached first.

Throughput measures the total amount of energy the battery can store and deliver over its lifespan. In the case of the aPower, it is designed to manage 43,000 kWh of energy storage and release while maintaining a capacity of at least 70% of its initial state.

This works out to roughly 3,161 complete charge and discharge cycles at full capacity, averaging around one cycle per day for over 8.5 years. As the battery ages, its capacity will gradually decrease, meaning each cycle will deliver less energy over time, extending the 43 MWh of guaranteed throughput across more cycles.