Most batteries, after a while of leaving idle, go flat and become unable to provide the power needed by vehicles and its equipment. Because leaving deep cycle batteries idle for a long time produces sulfate-crystals. It is barely an ideal situation because the sulfate crystal makes the plates separated from the battery acid. It causes short discharge or fast charging that leads the battery to become useless and ineffective.

The easiest way of handling this problem for some RVer is to buy a completely new battery. Instead of going for this expensive option, you can try and resuscitate the dead battery as a process. However, before attempting to revive the dead batteries, you must first know the voltage of the battery.
How to Bringing Back a Deep Cycle Battery to Life
While going through the steps, there is a need for applying caution. Use gloves with safety goggles as a preventive material to avoid contacting toxic substances throughout the process.
Step 1: Battery cleaning
When the batteries start getting older, corrosion starts to develop. You can identify the corroding nature of a battery from the appearance of white powder on the battery exterior. They are highly toxic and waits for their removal before applying anything. So, prepare a cleansing mixture of proper substances of a pound of baking powder in a gallon of water – mix it well in a basin. Baking soda causes battery acid to become harmless. Also, add dish soap in the mixture if you have a greasy battery. With the help of two wrenches of the right sizes and remove the battery terminals. Now, take the prepared solution and a toothbrush to clean the clamps thoroughly along with the terminals.
When you are satisfied with the result, wipe them dry taking note of any damage or cracks. For a mechanically sound battery use petroleum jelly or commercial protection spray onto the terminals before reattaching the clamps.
Step 2: The battery cell lid removal
After the cleaning of the battery is done, the next phase includes the restoration process. In this step, use a screwdriver to withdraw all the battery cell lids. However, a needle-nose peril will also come in handy during this procedure. While maintaining the same safety procedure, detach the cell covers. No foreign object should be allowed to be dumped into the battery cells. Keep a rag at hand to easily wipe off any unwanted mess while working.
Step 3: Feeding the Cells Distilled Water
Any water that is not distilled water has minerals even though it looks clean. And the presence of minerals here is extremely unwanted because they develop corrosion. Pour the water through a funnel in the cells, there may oxygen and hydrogen remain and cause a spark or an explosion if the cells are not filled with distilled water. But avoid overfilling the cells because the overflowed water will contain acid. The battery size decides the amount of water needed in the cells alongside the acid levels in it. A 12-volts of battery genuinely require more water compared to a 6-volts of battery.
Step 4: The battery connection with a reviver
When the battery cells are done being fed with water, your battery should be expected to start working immediately. But prior to anything else, charge the battery with a regular battery charger and check if it is charging. Continue if it works, but failing to find any indication of charge, a battery rejuvenator will save it. It is a device that can pulsate power through the battery plates breaking the accumulated sulfate apart. When the sulfate removal is done, charging becomes possible once again.
Step 5: The battery voltage testing
After the charging of your battery is successfully covered, you will need a voltmeter for the next step. You must check how much of the battery charge is holding with the voltmeter. After allowing the charged battery to sit idle for the next few days check the battery voltage again. It is good as new if it can bear the same voltage for that period successfully. But check the voltage periodically when you have reinstalled your revived battery on your vehicle to make sure it is still holding its charge.
Step 6: Restoring deep cycle battery with an Epsom salt
Another effective method of bringing back a deep cycle battery to life with the help of Epsom salt. Do not forget to use protective means- safety goggles and rubber gloves while going through all the processes.
The foremost step includes testing if the battery will respond to its restitution process. To be eligible for the reviving process, the battery’s voltage range should be between 10-volts to 12-volts. If the voltmeter reading indicates a value lower than 10-volts, then continuing the process will be a waste of time.
Secondly, take about a half quarter of distilled water and heat to a temperature of 65.5 Celsius or 150 Fahrenheit. Put 7-8 ounces of Epsom salt to be dissolved in the heated water.
Next, while maintaining your safety process, detach the battery lids of the battery or drill if sealed through the cells’ shadow plugs located. Apply caution and drain out present acidic battery fluids. Now, the solution of Epsom salt has to make each of the battery cells full through a plastic funnel. Now, you need battery cap replacement or cover the drilled holes with plastic plugs into the battery. Carefully shake the battery to allow the solution to distribute evenly to all cell parts.
The final includes recharging the battery while following a slow charge. Let it sit for charging for about a minimum of 24-hours before reinstalling your battery into your vehicle. But for gaining full capacity, the battery needs to be charged for about three to four nights.