Pack up the caravan, hit the road and find that seaside view you’ve dreamed of. Sounds good until it gets dark and we realise we have no electricity. That’s where batteries and solar come into it. Virtually all caravans have them and rely on them, (well batteries at least).. Even those that connect to 240v in a caravan park can still be reliant on them so what’s the gossip on types of batteries to use and how much juice do i need. ?
Without getting too technical let’s take a look at our setup of batteries in the caravan.
We started off for the first 2 1/2 years with AGM batteries. These are most common in Caravans. AGM batteries are deep cycle batteries that come in a range of amperage values. They are not the same as the starter battery you have in your car.
The key to a battery is the ah reading. Ah is short for Amp hours. So for simplicity reasons, a 100ah battery means you can use 1 amp of electricity from that battery for 100 hours before the battery is totally flat. Connecting batteries in series doubles the voltage but keeps the amp hours the same.
Connecting batteries in parallel maintains the voltage and increases the amp hours. Refer to google if you want to know more but in general for caravans you’ll be connecting in parallel.
Having 3 x 120ah batteries connected in parallel gives us a total of 360ah of current we could use. however, a deep cycle battery does NOT like to go less than %50 charge or else the life expectancy of the battery drops dramatically. There’s a chemical reason for that which I won’t go into but feel free to read the battery university website if your curious. Therefore our 360ah battery system is effectively 180ah “useable” amps. Which means in one day if we used 180amps of electricity, our batteries would be %50 flat. That’s as low as we would want them to ever be, which equals 7.5amps per hour usage.
Everyones consumption is different so it’s hard for me to say to you that on average you’ll use x amount of amps per hour. You may be running three fridges 6 inverters and 20 laptops. That’s definately going to use more than someone who just turns the lights and tv on at night. So what i’m saying is it changes for everyone. However to get a guide on what you might need try this handy solar calculator
Even though it will vary for everyone, over the last three years we average 72amps usage a day. We run a 218 litre compressor fridge , inverters, phone chargers, laptop chargers, Tv and lights all on regular occasions during the day. Not to mention our smart home network is always running, so that’s an additional , Router, 16 Wifi switches, 2 x Raspberry pi’s (miniature computers for automation control) and a few other gadgets 🙂
In early 2019 we upgraded to Lithium batteries. Although still fairly expensive they have come down in price alot. There are the following advantages of Lithium batteries over AGM batteries that help ease the pain of handing over cash to purchase Lithiums.
For us as fulltime on the road who could be in the bush for weeks, Lithiums are definitely the way to go. Along with our 600w of Solar panels on the roof we don’t run out of electricity. I still watch the charge meter with a eagle eye but that’s just me 🙂 we can go 4 days with no solar before I break into a major meltdown and have to charge them by some other means. Been close …. but never got to that stage yet 🙂
The batteries we used were from iTech World. You can find their batteries here from memory each 120ah lithium was around $800. We also went from AGM batteries that were 32kg each to lithiums that were 11kg each, hence the photo above where i’m lifting it with one finger.
Enjoy a happy and fully lit up life 🙂