Solar Buying Checklist

Battery Capacity

A batteries capacity is the amount of electric charge it can deliver at the rated voltage and is  measured in amp-hours (Ah) or watt-hours (Wh). The higher volume a units battery is, the greater the number of days backup it will be able to provide in case of overcast weather.

Battery Voltage

The potential difference or electrical “pressure” contained within a battery. Battery voltage is determined by the batteries internal construction and chemistry and is useful for converting Ah into Wh or vice versa. The formula’s to do this are;

Wh = V*Ah

Ah = Wh/V

Battery Type

There are three types of battery commonly used in solar lighting, each with their own advantages and drawbacks.

Lithium-Ion – Lithium-Ion is the most commonly used battery type for solar lighting and is similar to the batteries you will find in your smartphone or laptop. A low maintenance, high density battery type, Li-Ion batteries have no memory or scheduled cycling.

Lithium-Phosphate (LiFePo4) – An advanced battery type found in high end solar units, Lithium-Phosphate batteries experience a slower rate of capacity loss compared with standard Li-Ion batteries.

Deep Cycle Gel AGM Batteries – Gel AGM batteries allow for a lower price point then LI-Ion or LiFePo4 batteries however their life cycle is not as long.

Battery Warranty

All batteries degrade over time. A units battery warranty will suggest how long the battery on your unit will last for before needing replacement.