Deep-Cycle Batteries. What Are they,
and Why Would I Need One?
Though they use the same lead-acid type chemistry, deep-cycle batteries are of a different design and offer benefits that stand apart from a standard car-type battery.
A BIG DRAW
The configuration of the plates in the deep-cycle battery allows it to run a steady amount of current over a much greater period of time than a car battery. Thicker plates decrease the surface area of the chemical reaction. Where-as a car battery has thinner plates that increase the surface area, allowing for much larger surges of power.
The tradeoff for the deep-cycle battery is its ability to provide electricity in large surges is diminished. Other benefits for this configuration include being able to be discharged nearly completely over and over again. That type of pattern would ruin a car battery in short order.
HOW ARE DEEP-CYCLE BATTERIES RATED?
The reserve capacity (RC) of a battery is where all of this chemistry turns into something measurable and meaningful to the user. This is a rating of how long a battery is able to maintain a voltage of 10.5 volts at 25 amps. This gives an idea of how well the battery in question will keep your lights on and radio running during the length of the day.
The other main rating is Cold Cranking Amps (CCA), which is a rating of how many amps can be provided over 30 seconds at 32 degrees Fahrenheit. This is what is required to start your car engine and other high demand/short duration type situations.
Common uses for deep-cycle batteries:
- Marine craft and marine accessories
- RV’s, Fifth-Wheels, trailers
- Materials handling, including forklifts
- Golf carts
- Off-grid renewable energy
TYPES OF DEEP CYCLE BATTERIES
There are two common types of deep-cycle batteries, “maintenance free” or sealed, and flooded.
The “sealed”, “Maintenance-free” or “Valve Regulated Lead Acid” batteries don’t require regular maintenance of the battery. But just like any piece of equipment, it is suggested that they are still regularly inspected.
The flooded deep-cycle batteries need more attention with regular monitoring of the electrolyte levels. When these get low, performance suffers.
We hope this brings a bit of clarity between these two important battery types. If you have any questions at all, we look forward to your call or email.