The Complete Guide to Troubleshooting Deep Cycle Battery Issues

Did you know that deep cycle batteries are the most common type of battery used in cars? They are pretty handy and serve many purposes, but they can also be tricky to work with.

Like any piece of equipment put under a lot of strain over time, they can develop issues. And if you don’t know what those issues might be or how to fix them, then your battery won’t last as long as it should – or worse yet – stop working altogether.

Continue reading and learn some tips on what you should be doing to make sure your deep cycle battery stays healthy and lasts a long time.

This guide will cover some common ways to troubleshoot a deep cycle battery to get it back up and running quickly.

Deep cycle batteries and their uses

Batteries are an integral part of most off-grid systems, and deep cycle batteries are designed to provide the power needed for long periods.

Deep cycle batteries serve many different functions, but their primary use is in electric vehicles where heavy loads are needed for extended periods of time. They can also be used for powering RVs or boats and other devices that require a lot of energy – such as a refrigerator or electric oven.

The good thing about deep cycle batteries is that they’re very versatile and can be used in many different applications. But the downside to this versatility is that because there are so many ways for them to fail, it’s crucial not only to know what those malfunctions could be but also how best to troubleshoot them.

How to troubleshoot deep cycle battery problems?

1.Check your deep cycle battery

Not all batteries are created equal. But if you’re going to invest in a battery, it’s best not just any old thing off the street corner. Batteries contain sulphuric acid and lead, which can cause corrosion or damage that will shorten their lifespan considerably.

So this means before buying your deep cycle battery for use with an RV or solar power system (or anything else), check out what kind of battery is right for you by looking at its outside first. But how to check deep cycle battery?

  • Does the top look clean? Is there rust on the connections? Does water accumulate near them when they get wet during storms and rainstorms?

You can predict early signs of failure by simply checking the outside surface of a deep-cycle battery. It is in good shape if the top of it is dry and clean. One of the more overlooked causes of battery failure is grime. Dirt and dust can accumulate on a battery, causing it to discharge all at once across the dirt when in use.

Deep cycle battery seems to have suffered from overcharging or overheating at some point before they are inspected. When looking them up close, make sure that all of their cases appear intact.

  • Check the battery for broken or loose terminals. It is best if you also inspected whether it has any leaking. If a leak needs to be fixed, take precautions like wearing gloves and goggles to avoid getting contaminated with acid.

One good example is the AGM deep cycle battery which has a design that prevents leakage even when damaged, which saves you the headache of dealing with messy and expensive cleanups.

The Advanced Glass Mat (AGM) technology on these batteries is what makes them so unique; not only does this prevent damage to your equipment from leaking acid, but it also charges faster than any other type of battery.

Cracks and holes can be unsafe for deep cycle batteries, which is why it is important to discard any that have reasonably damaged the battery cases.

2.Voltage test

You can use either a multimeter, wattmeter, or a voltmeter to test the deep cycle battery’s charge level.

Should you decide to use a voltmeter, it is recommended to use a digital one. Using a digital meter can save you a lot of time because it will show the voltage level instantly and accurately.

3.Analyze the data

After testing the deep cycle battery’s charge level then it is time to analyze the data. The information on your device should tell you how long it can power equipment before requiring a recharge.

It will also show if there is an issue with overcharging or overheating, so once this has been checked, then all that needs doing is checking and replacing any parts of the deep cycle battery necessary – which is a job for the professionals.

Analyzing data should give you a better idea of what’s going wrong with the deep cycle battery, as well as if there are any indicators of imminent failure. Just remember that a voltage of over 12.8V-13V signifies that the deep cycle battery is fully charged.

If your batteries show an acceptable voltage on full charges but quickly drop down under 11V once they’re depleted, chances are some problem exists in either their design. This could be due to inadequate protection against vibrations while driving across bumps or simply factory errors that make repairing these difficult.

A dead or flat battery should show 10.5 volts. If you have kept it in the storage for too long without charging, the test will show the voltage below 10V.

When the battery test results to below 10V, this means that most chargers will not be able to detect it as they are designed for batteries with higher voltages, making them difficult or impossible to bring back when needed.

Frequently Asked Questions

How long does a deep cycle battery can last?

A deep cycle battery can last anywhere from two to ten years, depending on how well it’s taken care of.

They can withstand many more charging cycles than traditional car batteries, but they will wear out and must be replaced in the end.

How do I know if my deep cycle battery needs to be replaced?

A deep cycle battery will need to be replaced when it’s no longer able to charge fully and its ability to recharge starts decreasing. If your voltage is below 10V, then you’ll know that the replacement is necessary.

What are early signs of impending failure for a deep cycle battery?

If there are any cracks or holes in the battery case, if there is a leak or loose or broken terminals, and if with voltage reading of below 10V, then chances are your deep cycle battery is failing anytime soon.

What is the most common cause of a deep cycle battery failure?

Several things can cause a deep cycle battery to fail. Overcharging is the most common among them. If you continue using your equipment with this issue, it will damage other components in the machine.


Deep cycle batteries are not as fragile as they seem. It is possible to take care of them and prevent any problems that may arise.

You must know the differences between when your battery needs replacing or if there’s something else going on with it and some handy repairs can still be done.

But of course, if you are unsure of what to do, it is always best to seek professional help.

We hope that this article was helpful to you in understanding how your deep cycle battery works and learn some troubleshooting techniques when needed.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.