The 12-volt electrical demands of the modern RV require increased battery capacity to power devices such as digital televisions, lighting, ventilation fans, water pumps, slideouts and power inverters. One way to increase 12-volt battery capacity is to install more batteries in parallel. The parallel battery configuration ties additional batteries together, providing increased current delivery capability since each battery contributes to the current demands equally.
Things You'll Need
- Deep cycle RV battery
- RV plastic battery box
- 24-inch, 4-gauge black automotive battery cable with lugs
- 24-inch, 4-gauge red automotive battery cable with lugs
- 1/2-inch open end wrench
Choose a battery comparable to the one you're using in your RV. Match the age, capacity and brand as closely as possible. If you can't find a match, replace the battery with two identical 12-volt deep cycle batteries specifically designed for RV usage.
Disconnect the RV's AC power cord, turn off all AC breakers and turn off or unplug any 12-volt appliances and devices. If the RV has a battery disconnect switch, switch it to the OFF position.
Find a suitable location near the RV battery and mount the new battery box by securing it using the same method as the current battery. Place the new battery in the battery box. Additional mounting framing may be required to support the weight of the additional battery.
Connect one end the red battery cable to the positive (+) post on the new battery using a 1/2-inch nut and the 1/2-inch box wrench. Some batteries use a wing nut to secure the cable. You can use either the 1/2-inch nut or the wing nut. Connect the other end of the red battery cable to the positive (+) post of the original RV battery. Secure the cable to the post using the original battery cable connection hardware.
Connect one end the black battery cable to the negative (-) post on the new battery in the same manner as Step 5. Connect the other end of the black battery cable to the negative (-) post of the original RV battery. Secure the cable to the post using the original battery cable connection hardware.
Secure the cover of the new battery box using the supplied strap. If the RV has a battery disconnect switch, switch it to the ON position. Try a few 12-volt devices and appliances to ensure the 12-volt system is functioning properly.
Tips & Warnings
- Replace your original battery if it is older than one year. Batteries wired in parallel should be as close in age as possible to ensure the best long-term performance of both batteries.
- Performing any electrical work on your RV can be dangerous. If you are unsure about working with electrical systems, consult a qualified RV technician for assistance.
- Photo Credit Creative Crop/Digital Vision/Getty Images
How to Hook Up RV Batteries
Connecting the battery or batteries to your RV is simple and can be done two ways: parallel and series. Parallel is needed...
How to Charge RV Batteries in Parallel
RV batteries are 12-volt deep-cycle automotive or marine batteries. They are generally made with a lead-acid core, but there are different hybrids,...
How to Connect Two RV Auxiliary Batteries
Recreational vehicle auxiliary batteries are useful as they ensure that, despite using battery energy to power your RV electrical items while you...
How to Wire an Onan Generator to My RV
Any enclosed camper with wheels, used for fun or getting away from regular lifestyle, could be called a recreational vehicle, or RV....
How to Install Motorhome Batteries
Motorhome batteries must serve two distinct purposes. The engine battery, properly called the chassis battery, must function like any battery on an...
How to Wire Two 12-Volt Marine Batteries in Parallel
If your boat batteries discharge too quickly, adding a second battery can help. By having 12-volt batteries connected in parallel, they both...