What is the ideal type/size battery for a blacktop caravan?

Bit hard to answer exactly.
Think of it like this.

You've got a bucket, a hose, a thirst, a hole in the bucket and a limited intermittent supply of water.

You need to know how thirsty you are. ( how much power you will consume )
You need to know how quickly you want to drink the water. ( size of the hole )
You need to know how much water you can get from the supply. ( size of panels and hours of sunlight )
You need to know how much water to have in the bucket to last between it being topped up and drained out. ( size of the battery )

Add to that if you keep emptying the bucket it perishes in the sunlight ( ie flatten the battery to much and it doesn't live as long ).

Then take into account a large amount of conflicting advise available from the internet, usually argued in a painfully pedantic manner, and it's easy.

After everyone has finished adding 0.22c worth to the pot, it's all a guesstimate. As a clue, most batteries used seem to be around the 100Ah capacity and usually one or two of them are part of the kit. But you need to do some maths to work out what you need, what you think you need and what is realistic.
Good luck. Just remember it takes some thought, but not to much, as you'll work out from the quality of the advise from the hoard of budding Cape Canaveral candidates out there.

adRR,

What loads do you put on the battery? ie, what do you use the inverter for, and how long do you do that each day? Do you have a TV? Satellite dish? Radio, CD, DVD player?

If it's as simple and bare-bones as your post suggests, with minimal use of the inverter perhaps for charging phones, cameras, etc, then one 100 amp-hour battery would be ok. Deep cycle is best.

In general terms your 220 watts of solar would support about 200 amp hours of batteries, so if your power useage is up there with TV, DVD, satellite box and biggish stuff being powered on a regular basis either 12V direct or by the inverter, then I would double the battery capacity.

Cheers

Hi Dingo

You really need to look at the balance between your energy requirements and recharging options, and consider any inefficiencies in the system. You might find Electricity for Camping a useful read when considering these factors.

I'm a bit worried about "Anderson connection to car battery" which sounds a bit too simple! You do need a bit more than that! Dunno what you mean by "solar lights 'n stuff" either - could be some hidden worries in there. Your major consumer is almost certainly a fridge - type of fridge (3way or compressor type) is critically important. Maybe there's also a freezer to worry about? How long do you need the system to be self supporting away from mains power - 1 day, 3 days, a week, .......?

My best answer to your question is - Depending on your load, I'd be looking at 1 or probably 2 AGM batteries, each of about 100 Ah capacity. There are a lot if if's and maybe's in there though, and especially if it's a 3 way fridge - that would call for a whole new approach.

Cheers

John

Why did you purchase a 600 W inverter? Has this been tailored to an appliance you have in hand? If so what is it and what its power consumption. Alternately are you just one of those poor unfortunates that a salesman has told you you will need it? A lot of us try to use equipment that operates from 12 V and thus does not need an inverter. We often have a portable 60 - 150 W inverter in case we absolutely need to run small 240 V appliances. Using too large an inverter wastes power.

Quote "Would not have a lot of use as I have solar lights 'n stuff"

Solar lights do not need a external battery, possibly you mean LED lighting. We need to know what the expected current draw of the lights and what the " 'n stuff" is to know the size of the battery will need to be.

After saying all that, I have LED lights that draw 0.6 A each and an outside 2D tube that draws 1.1 A. We also have a small TV and a car radio, the radio runs all the daylight time we are in residence. A 115 Ah battery fed with a 80 W panel keeps us in power

A major point to consider is the weight of your chosen system. Batteries are very heavy, so don't forget the weight comes off your allowable payload.

Go the biggest in capacity and as for battery type...... I will not comment as it will lead to fighting among the battery brigade adding confusion.

Or as the method used to determine how sweet the orange is. Suck it and see.

Stick a 100 AH DC battery in and give it a go. My choice would be an AGM, but if the budget will stretch that far go Lithium Iron plus all the gadgetry needed to charge it properly. Less weight and apparently don't mind being dragged way down in charge.
If you go AGM or flooded lead acid don't drag any more than about 50% of the charge out regularly or you will shorten it's life. Time to add another 100 AH battery to the mix.

Cheers
Pop

There is no ideal type and size battery....its that simple or complicated depending on how you look at it.


It always comes down to hoe much you want to pay or carry.

The simple answer is " as big as is pracrtical and afforadable"


Now my pet hobby horse...AGM batteries.

In my opinion AGM batteries are very much oversold..in most situations they have absolutly no advantage over an equal quality sealed flodded wet cell battery.

people are being sold AGM for two very good reasons....the seller makes more money out of AGM and AGM can be freighted far more easily....this makes them more attractive for smaller volume sellers who rely on selling individual items and shipping them on normal carriers.

All the technological advances and all the technologcal advantages of AGM can be found in other batteries that cost often half the price....but lots of people don't want to hear this.


OH..BTW...ALL batteries including AGM need to be housed properly and properly ventilated.

cheers