Choosing the Right Auxiliary Battery for Your Caravan, Camper, RV, or 4x4
Why do I Need a Second Battery?
There are several reasons why a second battery is an essential part of your camping setup.
It provides electrical power to run various appliances and devices, such as lights, refrigerator, water pump, entertainment systems, and other electrical equipment that you may use during your camping trips. This allows you to have a reliable source of power even when you are camping in remote locations where access to electricity may be limited or unavailable.
Many camping enthusiasts enjoy the freedom of camping in off-grid locations, away from established campgrounds or hook-up points. An auxiliary battery allows you to power your essential appliances and devices without relying on external power sources, such as campground hook-ups or generators. This provides you with the flexibility to camp in remote areas and enjoy the beauty of nature without sacrificing basic comforts.
What type of Battery do I need?
- You’ll often see Lithium batteries branded as either Lithium-ION or LiFEPO4 (Lithium Iron Phosphate), I’ve written a quick summary on the differences between the two here. Lithium batteries are known for their high energy density, which means they can store a large amount of energy in a relatively small and lightweight package. They are commonly used in portable electronics, electric vehicles, renewable energy systems, and camping equipment due to their long cycle life, lightweight design, and ability to provide reliable and efficient power. However, it’s important to handle and use lithium batteries safely, as they can be sensitive to overcharging, overheating, and physical damage.
Pros Cons Lightweight Expensive High capacity Extra considerations when installing More efficient Longer lifespan - AGM (Absorbent Glass Mat) battery is a type of lead acid battery. AGM batteries contain a fiberglass mat soaked in electrolyte, which is placed between the battery’s positive and negative plates.
AGM batteries are known for their maintenance-free operation, as they do not require regular watering or acid level checks like traditional flooded lead acid batteries. They are also highly resistant to vibration, making them suitable for rugged applications, including camping, boating, and off-grid power systems.
Pros Cons More budget friendly than Lithium Very Heavy Low maintenance Shorter Lifespan Readily available Only ~50% of the rated capacity is
What Size Battery do I Need?
First you need to determine what you will be running and the current draw of those devices or accessories. You can use the calculations I provided in our Inverter article to work out the current draw of your setup.
Once you’ve figured that out you will be able to work out the battery size you will need. Depending on your set-up you might find you will need more than one battery to supply everything.
Most people with a simple set-up (fridge, few lights, small inverter) will start with a 120ah and work from there.
You will also need to consider if you have the means to recharge your battery during a trip. Will a DC-DC Charger or Solar panel recharge it or will you need extra capacity until you can get home and recharge everything?
In my car I have a 120ah Lithium Battery, a DC-DC charger to recharge when i drive and a fixed 160W solar panel to recharge when I’m stationary. This easily runs my 75L fridge full time as well as a few camp lights.
Remember, for Lithium the rated capacity is considered the total amount of useable energy. If you have a 100ah Lithium battery, you can use 100ah or energy.
For AGM, you need to cut that in half. For a 100ah Battery you will have 50ah of useable energy.
Conclusion
In my opinion they are superior in all the right ways and if you buy a quality battery you won’t have to worry about buying another battery for quite some time!