12 volt and solar

To run a solar shower you only need a very small battery and to carry a heavy and inefficient old car battery would be a waste of space. You could even rig up an extension lead and run it off the cigarette lighter in the car.

If you really want to carry an extra battery you'd be better off getting a small sealed lead acid battery say 7 or 8 AH, or a Jump Starter unit, which would potentially be useful for other things. A 20 or 30 watt solar panel would be plenty for that sort of thing.

For the Waeco you'd need to decide if it's going to be a fridge or freezer and what size it will be as it'll use lots more power as a freezer and the bigger the fridge the more power as well.

If you are considering running a compressor fridge, you will need a battery in the order of 75-100Ah and preferably of AGM construction. An AGM battery is safe to use anywhere within a vehicle and can be tipped over or even operated on it's side without compromising safety or efficiency.

Although most of us set up the battery to enable charging from the vehicle alternator with an in-car charging kit which includes an isolator to protect the starting battery, a solar panel is a great addition to supply a charge to the battery when stationary at camp.

I found I could get a suitable charge back into the battery with a 40 watt panel (about 5 anps) in the few hours of daylight available, however a minimum of 80 watts is a better solution for greater flexibility, at a reasonable cost. I have since added another 40 watt panel to give me an 80 watt bi-fold panel which I have found to be adequate, however I don't use my fridge as a freezer.

Hi Michelle,

Welcome aboard!

As already suggested, the shower doesn't need much power, so could be plugged into the car cigarette lighter through a reasonably long lead. (Or the fridge battery.) Certainly a tired car battery would be fine, though, again I'd agree with other posters, it's inconveniently heavy and not really needed if you can plug into the car. The other very big downside of vehicle batteries is that they contain lots of sulphuric acid which is dangerous corrosive stuff. If you do need a battery for the shower, suggest a small sealed type.

The fridge - power requirements depend on size and usage patterns. Fridges fall roughly into two groups - the small ones (less than about 60 litres) draw about half the power required by the larger ones. Obviously if you want them to run freezing cold they'll need much more power than if they just need to keep the milk cool. Opening the fridge frequently, especially in hot weather will also have a big impact on power requirements.

How much solar to power the battery that powers the fridge? Very roughly, for a small (say 40 litre) fridge you'll need a 100 amphour deep cycle battery (preferably an AGM type where the acid problem isn't an issue) and this will have the capacity to run the fridge for 2 or 3 days. To replace all the power used by the fridge in 24 hours you will need at least an 80 watt solar panel and a sunny day.

For a far more thorough treatment of this please see the blog Electricity for Camping where you'll find a lot of stuff that should be helpful in setting up your rig.

Cheers

John

Lets start at the beginning, its a very nice place to start.

Unless you are going away for more than 2 or 3 days, solar is pretty pointless.

If you chill your fridge down properly first, keep it in a cool place and maintain good fridge discipline, you should be able to run a small 30-40 liter fridge AS a fridge for 2 or 3 days off a decent N70 battery that is in good condition, without recharge.

If the fridge is in the vehicle and you are driving that vehicle for at least 2 hours a day, you should be able to run such a fridge indefinitely off a properly rigged second battery.

As for the electric shower......work out the consumption...you will probaly un it off just about anything

As for running the fridge off solar for longer periods, a minimum of an 80 watt pannel to be of any advantage at all and at least 160 watts for reliable continuous operation.

search this and other forums there is plenty to read on this subject.

cheers

Thank you for your assistance.

We are in the process of setting up a semi permanent camp for campers so transport of battery will not be a problem. Just keeping it charged without a vehicle on site would be more of an advantage.

So camp shower and toilet would be available on site and available for campers.

NOW, if theis is a semi permanent site...that is a different game altogether.

Even more important to have adequate pannels to keep the batteries charged, and less of an issue about the size and weight of the batteries.

two 180 watt pannels and a 200AH deep cycle battery would be a good place to start...of course you will need a regulator for the solar pannels.

A basic 40 amp reguator would be a minimum, a maximum power point tracking regulator, would be better if you have the $$$

I'd steer away from using an old battery unless it was just for the shower and that was set up as a completly seperate system.

cheers