Why Do I Need A Deep Cycle Battery?

Why Do I Need A Deep Cycle Battery

To fully enjoy the outdoors and all it has to offer, many turn to deep cycle batteries and so enjoy camping, caravanning, and boating.

For the uninitiated, a deep cycle battery is essential for providing power over a sustained period of time. It’s designed to withstand constant discharge and to then be recharged, ready to use again. You might be wondering why you’d choose a deep cycle battery over a regular automotive battery. It’s obvious for boats, but why not just use your car battery when camping?

A car requires a high burst of power for a short time – just enough to get started. Cars use SLI (Starting, Light, Ignition) batteries, or ISS (Intermittent Stop Start) batteries. Only a small amount of the power stored in the battery is used, and then as you drive the car the alternator restores what was used. The way an automotive battery is constructed suits these requirements.

The power needs for camping or marine are different to automotive. They need energy over a long period of time, so they discharge to a lower level, and then recharge to full capacity via solar panels or simply connecting to a charger that’s plugged into a power point.

Deep cycle batteries are different to SLI or ISS batteries used in cars as they have:

  • Thicker grids and corresponding plates, which gives them longer life.
  • High density active material to increase capacity.
  • High percentage antimony in the positive grid alloy which improves cycling ability.
  • Separators made of rubber with a glass mat designed to retain active material and control water loss.

If an automotive battery is used for a deep cycle application, it will suffer damage that will shorten its life. So while you think you’re saving money by multi-purposing your car battery, you’ll be replacing it sooner and it won’t be covered by warranty.

There are a variety of deep cycle battery types. The one you choose will depend on where and how you want to use it.

Yuasa N70TX MF

Flooded Lead Acid Batteries

These are the most basic type of deep cycle battery. Lead acid plates are suspended in liquid consisting of acid and water. They are tolerant of different charge rates but may need to be topped up as water vapourises.

Century C12-75DG

Gel Batteries

A gel electrolyte, rather than liquid, and a sealed case allow the gel battery to be installed in tighter spaces where ventilation might be an issue. While they can remain discharged for a longer period, their charge rate must be strictly monitored and often needs a specific charger.

Optima 34 Red

Spiral Batteries

The spiral shape of the spill-proof case helps increase vibration resistance and decrease self-discharge.

Remco RM12-100DC

Absorbed Glass Mat Batteries

The acid in an AGM battery is suspended in a glass mat separator. This makes them spill-proof and leak-proof, as well as more resistant to shock and vibration.

Century 27X MF

Dual Purpose AGM

This offers the best of both worlds. It’s built tough to survive under bonnet so will start your car or cycle like a regular AGM battery. This is perfect for 4x4, light commercial, marine, and RV applications.


If all this information makes you wonder “Which one should I use?”, you’re not alone. Battery World have been helping people determine the best battery for their needs since 1997, so drop in to your nearest Battery World store today and speak to one of our local battery experts.