Whether you are on the road for a weekend or weeks on end, having enough power to get you through is vital. We answer some common questions about RV batteries, inverters and energy efficiency.
Which devices in my RV are likely to use the most energy?
Most RV lighting is LED these days, and modern RV entertainment appliances are extremely energy-efficient and won’t run your battery power low in a short timeframe. However, compressor fridges or 12-volt cooler boxes use a fair bit of energy, especially as you normally run them 24 hours a day while in use.
Inverters can also be hard on batteries because you lose energy in the process of converting from 12-volt to 230-volt, and many appliances used with inverters consume a lot of energy – for example electric kettles, toasters and hair dryers.
If you are using a lot of appliances all the time while freedom camping, or you are using a powerful inverter (1500-3000W), consider a battery and solar upgrade to avoid ruining your batteries in a very short period of time.
What is an inverter and how does it work?
An inverter transforms a direct current (DC) to an alternating current (AC). This allows you to use home appliances that run on 230-volt AC with your motorhome/caravan DC battery. It means you can take many of your home comforts on the road with you.
There are three types of inverters; pure sine wave, modified sine wave and square wave. Only the first two are really used in RV applications.
The advantage of the pure sine wave inverter is that the power output is much more stable, efficient and smoother. In particular, devices like laptops should only be operated with pure sine wave inverters. Pure sine wave inverters cost much less that they used to and are well worth the little extra they cost.
How often should I check my battery, and what do I need to check?
Before doing anything near your battery, it’s important to take a few safety precautions. Batteries produce explosive gases, so be sure to keep sparks, flames and cigarettes away at all times and ensure your eyes are protected.
First check whether you have a sealed battery (maintenance free) or a ‘wet’ flooded lead acid battery that requires maintenance. The easiest way to tell the difference is that batteries requiring maintenance will have plastic screw caps on the top that can be removed with a screwdriver. This gives you access to check the battery fluid level.
The maximum is usually shown by a plastic indicator protruding above the fluid level. Ensure that the plates are at least covered by fluid if you are unable to locate a level indicator. You should check the level once a month as some of the acid water mix will evaporate and a small amount will electrolyse into hydrogen and oxygen. Never top up with battery acid or tap water; use distilled water only.
If you have a sealed battery, you don’t need to worry about the steps above as this type cannot be opened.
Also check that terminals and all wires are secure, that the battery is not deformed, that wires don’t have any corrosion, and the battery is properly secured.
How should I store my battery over winter?
Batteries don’t like long periods in cold conditions or without charge. If you know you are not going to use your vehicle for an extended period, you should connect it to an intelligent multistage charger. This will ensure the health of your battery over the winter by running various cycles of charging and discharging, all without overcharging the battery.
Spending a little more on the charger will save you money in the long term as you won’t have to replace your batteries as often. If you remove the battery from the vehicle to charge it, be sure to leave it in a well-ventilated area such as your garage and avoid putting it directly on concrete flooring as this will reduce the battery’s temperature.
How long can I expect my battery to last?
Well maintained batteries can last anywhere from four to seven years. It is not recommended to run your batteries below 12 volts as every discharge will shorten their life.
How do I check the charging system?
Some RVs come with a display that will give you a reading for ampere hour charge and discharge or battery voltage as a minimum. You will see the voltage go up if on charge from 12-12.7 volts up to 15-16 volts, depending on the charger and the charge cycle it is running.
If the battery is connected to the charger but not charging, check the charger is still receiving power from the grid. A 230-volt RCD located in your vehicle or on the campsite supply line may have tripped out. It can be reset by flipping the fuse back up into the ‘on’ position. The RCDs look very similar to the ones in your house.
If you are unable to identify the issue, it’s best to talk to your trusted workshop.
What options do I have for powering my vehicle that won't drain the battery?
First, you can ensure all appliances and lighting are energy efficient and that you make use of thermostat settings in the fridge and heater.
Adding more battery capacity and solar power will give you more time to freedom camp. You can also add a diesel/petrol generator to your vehicle to recharge batteries and run appliances to extend your freedom camping capabilities. However, be aware that these will be noisy.
Lastly, making frequent use of powered campsites will also eliminate the problem and help you to stay on the road for longer.
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