Deep cycle batteries are a form of lead-acid battery that is specially designed to provide a steady current over a long period of time. Unlike their automotive cousin, they do not suffer ill effects from repeated deep charge depletion. Due to the way they are constructed they should be treated differently than an automotive lead-acid, or starting battery. So what is the correct way to perform deep cycle battery charging?

These kinds of batteries are used in applications where current is drawn over an extended period of time, without significant recharging taking place. This makes them ideal for power storage in a solar, or wind energy systems, and also for powering electric vehicles like golf carts, or wheel chairs.

Automotive lead-acid batteries differ in that they are designed to produce a large short current burst, this is needed when starting a car engine. Both however produce power in the same way. That is by a chemical reaction which occurs when lead plates are immersed in sulfuric acid.

To understand the correct way to charge a deep cycle battery, we have to understand the three different ways they can take on charge.

1. Bulk Charge.

In this kind of charging, current is sent to the unit at the maximum that it can take. The voltage is not important, but is typically between 10 and 18 volts.

2. Absorption Charge.

During this kind of charging the unit will deliver a constant voltage, but the current will be reduced as the cells natural internal resistance increases. This increased resistance occurs naturally as its charge level builds up.

3. Float Charge.

Also known as a trickle charge, this is the kind of charge given to an almost full battery. At this stage the charger will reduce the voltage to a minimum, usually around 12 volts. This is the kind of charge that keeps the power topped up.

With an automotive battery it is sufficient to charge it using bulk charge only, and this is the only type that most domestic chargers develop. To get the most from a deep cycle battery it is important that it is charged using all three of the above methods.

Doing this will maximize the life and effectiveness of your system. If your deep cycle battery is in a home energy system, then power provided by the source, (solar panel or wind turbine,) will be passed through a power regulator that will make sure the voltage, and current, supplied to the storage bank is appropriate for the level of charge that is already there.

This is important because over charging can lead to the liquid in the battery evaporating, and too much gas being produced, an undercharging can lead to a build up of lead sulfide on the plates. Both of these situations can lead to damage.

With these expensive storage cells it is important that you follow the correct deep cycle battery charging procedure. This will ensure you get the most from your investment.


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