RV Batteries – Care and Maintenance
RV batteries and their care and maintenance are a subject as a new RV owner you must acquaint yourself with. Batteries used in recreational vehicles have unique specifications and there is a need to know their requirements and the limitations of the application they are used for.
For recreational vehicle use the special applications will require the ‘the true deep cycle’ battery. Similar to the marine deep-cycle battery but much different, they are in fact a combination of automotive starting batteries and deep- cycle batteries. The marine type of battery does not meet the rigorous requirement of the RVs.
The true deep cycle battery for an RV will store more usable electricity and be able to be discharged almost completely and recharged many times. The common type is the lead acid battery with thick plates covered with acid electrolyte. They are available in many sizes and they have a long lifespan and are low cost.
The disadvantages are when they are being recharged, they produce toxic gases. Battery compartments must be well ventilated. This type of battery needs electrolyte level checked which is very acidic and extremely corrosive. From time to time they will need to be topped off with electrolytes and spills happen from time to time. Cleaning solution of baking soda and water can be used to clean the spill.
The next battery type is the lead antimony with caps and will need to be refilled periodically. The type that is “maintenance free” is the lead calcium and are sealed and are susceptible to failure when discharged below 40 to 50%. On the down side of lead antimony batteries self-discharge faster but more suited for use in RVs. Their tolerance for deep discharge and recharge is much greater.
The gravity meter is really the best way to check the state of a battery. This maintenance step RV owners pass on and the high quality meters used to check the overall charge of a battery can cost a few hundred dollars. What you get with the RVs today is the idiot lights (red, amber & green) which mean nothing. The best choice is to have a digital display voltmeter that provides the voltage readout. This is far better than the analog meter with a needle.
The digital voltmeter provides the RV operator with the most information available at the lowest cost. The best time to check output voltage is in the morning before the heat of the sun changes the numbers. The full charge reading is 12.65 volts. A charge of 50% reading is 12.6 volts and dead or zero charge the voltage reading would be 11.89 volts.
Premature battery failure is caused by primarily from overcharging. Some of the better battery chargers on the market today will auto-shutoff when charging is complete. This is best! The charging voltage from the charger should be 14.1V to 14.4V at room temp. The chargers that put out more charge voltage than that cause the acid boil and when this occurs gassing takes place. This is what causes overcharging plate corrosion and electrolyte loss.
Charging your deep-cycle RV batteries can be a challenge at times because gassing can occur while recharging on a hot day. So a much lower recharge voltage is needed. When it is cold the 14.1V to 14.4 charge voltage will not be enough to reach the edge of gassing thresh hold to stir the electrolyte so a higher charge voltage will be needed. Be prepared to add distilled water on very hot days when recharging your batteries even at the lower voltages.
We are starting to see high quality RV battery charges that compensate for ambient temperatures that do a great job of handling this problem. But you are going to find they are more costly.
Most issues related to deep-cycle batteries are the result of a lack of understanding of RV batteries care and maintenance. The proof of this is that 85% of all the batteries manufactured in the USA fail before they should. To learn more grab a copy the Deep Cycle Battery Care & Maintenance DVD offered below. You will learn to truly extend the life of you batteries with simple routine preventive maintenance.