Words and pictures by Greg O’Donoghue (C-Dynamics).
How to choose the right battery
Flooded-cell thin-plate cold-cranking batteries (your typical automotive start battery).
Universal batteries, capable of providing good cold-cranking amps (CCA) and a fair cycling capability – a good all-round choice.
Deep-cycle or traction batteries, designed to provide numerous deep discharges with a long lifespan – thick plate, robust construction.
Lithiumion (Li-ion) batteries, which are light, with a small footprint, and excellent deep-cycle capability – they accept very high charge rates.
Most of these batteries are available in open vented cells or in a sealed maintenance-free configuration. Charging open vented cell batteries at 14 V and +20°C produces a mixture of hydrogen and oxygen, so it’s important to ensure that these batteries are installed in a well-ventilated area. As this is not always possible, we will focus on the sealed maintenance-free range of batteries as our preferred choice.
Conventional lead acid A typical automotive start battery is designed to provide a lot of amps for a short period of time, rather than repetitive deep cycles. The plates are flooded with the electrolyte, which is a mixture of sulphuric acid and water.
In AGM (absorbed glass mat) batteries, the electrolyte is largely absorbed in glass fibre. This type of battery is entirely maintenance-free and there’s no gas formation with normal use. As they don’t require any ventilation, they can be installed anywhere. Their construction allows for a fast discharge at high currents, thus making AGM batteries ideal for running a winch or starting an engine. An AGM battery will provide two to three times the cycle life of a conventional start battery, making it a good universal battery.
In gel batteries, the electrolyte is absorbed by gel. This type of battery is entirely maintenance-free and has no gas formation with normal use. Because no extra ventilation is required, gel batteries can be also installed anywhere. They are ideal as a service battery and for cyclical use, as they can be charged quickly
These robust 2 V gel batteries are designed for regular and deep discharging (more than 1 000 full cycles), and are ideal for large systems that require intensive use and a very long lifespan.
Lithium ion (Li-ion) batteries have a high-energy density and are perfect for cyclic applications. They offer savings of up to 70% in volume and weight, compared to traditional lead-acid batteries, with three times as many charging cycles (over 2 000 full cycles).