Deep Cycle Battery Maintenance: How to Get the Most Out of Your Battery

An electric DC battery at an electrical station.

Deep cycle battery maintenance is crucial if you want to get the most out of your batteries. For those of you not in the know, deep-cycle batteries are one of the most cost-effective methods of energy storage. Flooded lead-acid deep-cycle batteries are designed to use most of their charge regularly: they do need to be properly maintained however, for your safety and for the battery’s longevity.

A common example of a deep-cycle battery is lead-acid car batteries, which can be traced back to 1859. This isn’t the only type, though! If you’ve recently bought a deep cycle battery, lifespan is of the utmost importance.

We know that understanding all this jargon can be tricky. We’ve compiled expert advice on how to maintain a deep cycle battery, to help you get the most out of your investment. 

Are you ready to learn these important tips? Then read on!

Charge Your Batteries Correctly

One of the most important deep cycle battery maintenance tips can be put into effect from the first charge. When you get your system up and running, you need to program your chargers. 

The chargers will work in three different stages: 

  • Bulk, to bring the battery up to around 80 per cent
  • Absorb, for the final 20 per cent
  • Float, for keeping a trickle charge when at 100 per cent

If you don’t program these charging points correctly, your battery life will suffer! When you’re programming these points, the charger needs to be set at a specific voltage. 

Voltage isn’t the only consideration you need to make when you’re setting up your charger. You should set rules on how long the battery spends in the absorb phase, input amps, and how it accounts for temperature. If you are using the battery in a hot climate, this last one will be crucial. 

When to Charge Your Batteries

Try and limit discharge to above 50 per cent if possible. Charge whenever you can. You will also need to allow the charger to go through a whole charge cycle.

Maintain Electrolyte Balance

You should keep a close eye on your batteries’ electrolyte levels and adjust as necessary. Add distilled water as necessary. You should add distilled water every 2-4 weeks.

Keeping your batteries’ electrolytic balance in check is key for getting the best performance and lifespan out of your batteries. 

Measure Charge with a Refractometer

If you’ve no clue what a refractometer is, don’t worry! Understanding how they work and how to use one is easy, and a key part of battery maintenance. 

They measure a battery’s specific gravity. When you know their specific gravity, you can calculate how charged they are to a very accurate degree. Every battery has different specific gravity at different charges, so consult your manufacturer for more details.

When a full charge cycle has been completed, your battery should be fully charged. If it isn’t holding a charge after a complete cycle, there is something wrong with your battery. A refractometer can help you diagnose these issues and save you time and trouble later on.

Equalizing Charges

Your battery is made up of cells. It is common for these cells to become unaligned, meaning that they do not hold an equal amount of charge. This can cause problems for your battery’s life. 

The key to removing this threat to your deep cycle battery lifespan is by carrying out equalizing charges. These bring the cells back into alignment, keeping everything in order.

To equalize, check your battery’s water. You should then consult your battery manual and find out what voltage to set the charger at to equalize the battery. Charge it and allow the electrolyte to bubble and gas. 

When the charge is complete, start taking readings with a refractometer every hour. When the specific gravity isn’t going up anymore, the process is complete.

Keep Battery Temperature in Mind

One important part of deep cycle battery care is keeping it at a stable temperature. The ambient temperature around your battery can severely impede its performance. 

In cold climates, battery capacities fall, in hot climates, their lifespan falls. When you are charging your battery, the charger should be able to take temperature data into account. Your battery will need more voltage per cell when it is cold, compared to when it is hot.

If your battery charger doesn’t take temperature data into account, consider investing in a new one.

Sealed Deep Cycle Battery Maintenance

These tips are all well and good but what if you are working with a sealed deep cycle battery? Sealed deep cycle battery maintenance requires a whole other set of information. 

In general, these batteries are a lot easier to care for. You don’t need to add distilled water, for instance. There is one key task that you will need to become familiar with: checking charge with a multimeter.

Use a Multimeter to Check Charge

Unlike flooded lead-acid batteries, you will not use a refractometer to check charge. Instead, you should use a multimeter, which will take DC voltage readings which can then be translated into information about its state of charge.

To get the readings, you will need to attach the probes to your battery and then check the readout. Consult your owner’s manual for information about how DC voltage relates to charge.

Never do an equalization charge on a sealed battery. 

Aside from this one task, there is little maintenance required on a sealed deep cycle battery.

Battery Care Made Easy

We hope that we’ve answered all your questions about deep cycle battery maintenance. While it can seem confusing, once you get the hang of it, you’ll be using your batteries to their utmost capacity all-year-round.

Do you have any other questions about our company? Need to ask us questions about our battery products? Click here to find out more about us and use the button in the top-right corner to get in touch with us!

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