How Long to Charge a Deep Cycle Battery – Proper Guideline For 12V

Hey there, as you are here, I think you are looking for how long to charge a 12v deep cycle battery charging instructions. We who is familiar with a deep cycle battery, face problem in charging, specially how long to charge a deep cycle battery. This battery works as a unique power source for cars and boats.

You can use deep cycle battery until it has no charge at all, then you can use a deep cycle battery charger to charge it back. As the charging process works with science, you have to know how to properly charge a deep cycle battery. Stick with me till the end to get all the information you want. 

Though you have best solar charger for 12V deep cycle battery still you have to know the proper timing of the charging.

Let’s know all the details from our given information!

What Is A Deep Cycle Battery? 

Every battery stores power. There are types of batteries; among them, the deep cycle battery is the different one. This lead battery can provide constant power until it has used up to 80% charge; on the other hand, the regular battery can provide only short power. For the power consistency, the deep cycle battery is used in different vehicles, boats and golf carts, etc. 

Read More: Best Lithium ion Battery for Rv Solar

The most used deep cycle batteries are flooded and sealed deal cycle batteries. 

  • The flooded battery requires to refill when the electrolyte level is low and regular maintenance. 
  • The sealed battery doesn’t need frequent watering as it needs less maintenance. 

What Is The Deep Cycle Battery Charging? 

Do you know how to charge a deep cycle battery properly? Well, that’s not a very difficult task.

To charge the battery, you will need a deep cycle battery charger. To charge the battery, you will need to go to some specific tasks. Let’s look at the tasks: 

1. Preparing And Cleaning The Battery 

Before charging the battery, you have to check the battery as it is ready to be charged or not. You have to check the liquid level of the battery you use. Also, check for corrosion and cracks in the battery. If your battery has problems, test them, and you have to use safety measurements like latex gloves and safety glasses.  Then use the brush to wipe the corrosion from the battery, and you can use baking soda and water solution to clean the hard corrosion away. 

2. Pick The Right Charger

Selecting the right deep cycle battery charger is important.  You can use 5 amps, 10 amps, and 15 amps charger for the battery. Check the wires and connectors of the old battery charger. 

3. Charging Time 

To let the cycle to provide service for long years, you have to maintain the charging time. It is best to charge the battery when it is left with 50% power. 

Don’t overcharge the battery because it limits the batteries function level. You have to charge the battery per the amp specification and discharge value. For example, a 15 amps battery charger will take two hours to charge a battery; a 5 amps battery charger will take six hours to charge the battery. 

How will you find the charging time form a deep cycle battery charge time calculator? Well, the time depends on the storage number of the battery. Divide the batteries amp hour rating by the charger amp rating. The number you will find is the approximation time of the battery recharge.  If you have a 100 amp battery, then the battery will take 5 hours to reach the 50% battery capacity. 

Deep Cycle Battery Charging Instructions To Follow: 

While charging the battery, you need to maintain some rules to make the charging proper. 


At first, you have to check the performance of the battery at different temperatures. Because we have to use the stored power in the temperature limit. For example, in the cold wintertime, the battery capacity gets low, and they don’t work properly, and again in hot summertime, the battery also fails to work. 

The deep cycle battery charging voltage also works as a factor in temperature because it needs a high voltage charge when the battery is cold. So a good battery needs to have the feature of automatic temperature compensation to charge the battery smoothly at any temperature. 

Understanding The Charging Cycle 

The next one is to understand the charging cycle. The maximum deep cycle battery needs recharge when it comes to a significant level after usage. Usually, the battery capacity depends on usage consumption. A regular deep cycle battery comes with 100% capacity, and after power consumption when the charge comes between 20-50%, then you have to recharge the battery. 

Don’t push the battery discharge to a greater depth because it will make the battery’s lifespan shorten. If you charge the battery when it reaches 50% discharge depth, then it will give you service for long more years. 

Recharging With A Float Charger 

Recharging the battery with a float charger is an interesting one. This charger charges the battery in three stages. The first stage is the battery will get charged in the bulk charging phase; in this phase, the battery will get the highest voltage. When the battery gets charged to 80%, then the battery goes to the second stage. 

In the second stage, the battery will switch to the absorption charge phase. This time the batter will consume constant voltage until it reaches 90-95%. 

Then comes the last stage, the float phase. In this phase, the voltage flow gets less until the battery reaches 100% capacity. You can see the charger changes the voltage flow in every stage until the battery gets fully charged. 

Using Solar Power 

Lastly, charging a deep cycle battery with solar energy. Yes, you can charge the battery using solar power. This charging option works well when you are on the water for fishing or water-related work. You have to invest in solar panels to enjoy this clean power source. When you are charging your batteries, the charge controller will control the unstable power that the 12V solar panel will produce. So you will have safe voltage power to charge the battery when you need to. 

Read More: How Do I Use My Cpap Without Electricity

What is the Solar Charger for 12V Deep Cycle Battery?

Among all the charging systems, a solar charger is the best solution if you want to charge deep cycle batteries without harming your budget and time. In any place, you can charge deep cycle batteries if you have the solar charger solution.

#1 Mighty Max Battery 10 Watt (Check this on Amazon)
#2 SOLPERK 12V Solar Charger (Check this on Amazon)
#3 SUNER POWER 12V Waterproof Charger (Check this on Amazon)
#4 POWOXI 7.5W Waterproof Solar Panel Trickle Charging Kit (Check this on Amazon)
#5 Paladin 2PK 12V Solar Car Battery Charger (Check this on Amazon)

Q1. How long will it take in charging a deep cycle battery 2 amp or 10 amp? 

Ans:  Charging the deep cycle battery in a 2-amp charge will take a long time, and the discharge time is more than the amp charge. But with a 10-amp charge, you can charge the battery in 15 hours. 

Q2. Can you overcharge a deep cycle battery? 

Ans: No, because the overcharging will cause rust in the grid and reduces the battery life severely. 

Q3. Can I charge a deep cycle battery with a regular charger? 

Ans: Yes, you can charge the deep cycle battery with the regular charger. Because there is no big difference between the deep cycle battery charger and the regular charger, the deep cycle battery charger can charge it in a small amount for a long time. In contrast, the regular battery charges the battery in a short time with a large amount of electricity. 

Q4. How fast can I charge a deep cycle battery? 

Ans:  the charge time depends on the battery size, charger, and temperature. If you charge a 100 amp battery with a 15 amp charger at room temperature, then it will take 5.33 hours. 

Q5. How long does it take to charge a marine battery? 

Ans: Depending on the battery’s condition, it may take 12 hours or more hours to recharge. 


The deep cycle battery is designed to use a low depth of power release. This battery can discharge power up to 70-80%.

You can use the battery for more use. You will need a proper charger to charge the battery. To pick the right battery charger, you have to calculate how long to charge a deep cycle battery. By this calculation, you can use the battery until it reaches the discharge value.