How to charge your deep cycle batteries

Charging A Deep Cycle Battery

When you charge a deep cycle battery is really helps to know exactly what the best way to go about it is. In this piece we will take a look at how a deep cycle battery should be charged.

When we discuss a deep cycle battery we first need to be sure that we are all on the same page. So we need to tell you a little about what exactly a deep cycle battery is, and then we will make sure you know how to keep it charged.

Proper ways to charge your deep cycle batteries

A deep cycle battery most commonly is a 12 Volt, six cell battery. It is usually negative grounded and always works with lead-acid.There is some variety in the types of lead-acid deep cycle batteries, such as flooded, gelled or sealed (AGM or absorbed glass mat).

This means that a deep cycle battery is essentially a device that stores electricity through electro-chemical processes. If the battery is rechargeable this process can be repeated many times, but it is good to remember that batteries are not completely 100% efficient when it comes to energy usage. Some of the energy will be lost as heat, or as chemical reactions and some due to the internal resistance of the battery itself.

Deep cycle batteries are designed with thicker solid plates (the lead plates that are used to create the current within the battery) so they will typically be able to run down to 20% repeatedly. The solid plates also differ from the sponge plates that other types of batteries usually have.

The fact that a true deep cycle battery has solid plates, gives it less instant power, but longer consistent power.  There are also industrial deep cycle batteries, designed for forklifts and so on, that are larger and have larger lead plates as well.


The way you use, maintain and charge your deep cycle battery will influence how long it will last. So if you treat it well, it will last quite long and this will save you money in the long run. Who can afford buying thousands of batteries, when you don’t need to?


Temperature can really change how a battery performs and charges. When the temperature plummets in winter, your battery capacity also goes down. The opposite is also true, when it gets warmer the capacity also goes up. But with the heat, the battery life is affected.

Battery life is reduced at higher temperatures.  Charging voltage is also influenced by how hot or cold it is around the battery, so a nice even temperature will really help your battery last.

When you charge your battery in conditions where the temperature will vary often, you will need to keep it in mind. This means that you will need charge control or a temperature compensation function for your charger.

Some chargers have this feature built in, but you need to keep the battery and charger at around the same temperature for this to work. There will be no use in charging a battery that is outside in the cold, with a charger with compensating factors built in, if the charger is inside and warm.

Stages of charging a battery

When you charge a battery there are three main things that happen. The first is Bulk charge, then the second stage is the Absorption charge and then lastly the Float charge.  Most commercial chargers work with bulk charge.

Tips and tricks

A few things to remember to help keep your deep cycle battery working well, is good maintenance goes a long way. It is that it is a good idea to let the battery cool down after charging.

Like we said above, the heat lessens the battery life, so if you give it a moment to cool down, there will be less grid corrosion. Another thing to avoid is opportunity charging (or charging the battery quickly between every use), because you also miss the cooling time between cycles.

Don’t mix and match. With this we mean that you shouldn’t charge a battery with a charger that was designed for another type. A wet battery does not do well after a charge with a sealed cell battery charger and the reverse is also true. It reduces the capacity, and lifespan of the battery and also dries out the battery needlessly.

Don’t leave your deep cycle battery in the lonely recesses of your garage. They are designed to be used. So if you aren’t going to use it for a few months be sure to give it booster charges to keep it happy. It can be once a month in warmer areas and about once every two months in colder climates

Last Words

Hopefully you have a better idea about how deep cycle batteries can be used and charged so you get the best out of it.

Originally posted 2017-07-12 20:17:38.

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