Solar power, heating & lighting for terrarium

[donkey]

ok this is a simple question but i like pictures so if you can draw a schematic for me it'd be great.
need to find and run a heating element and uv light and a fluoro light in a tarrarium(thats probably not spelt right).
i want it solar powered with battery back up.
the questions are as follows using this setup the uv light and fluoro get turned of at night but the heating element doesn't. what size battery and solar panel should i use? i am hoping to find most of this pre built so if you know of a link to a 12volt heating element with adjustable temp that would be awesome. the uv light is another one that i hope can be powered throughout the day and turned off at night but does anyone know what current draw it has? and as for the fluro this is so we can see in... a few leds might suffice for this to save ampage and prolong the power stored in the battery. if anyone can help me out figuring out the battery and solar panels that would be awesome. i am googling the rest for now and when i find the right items i will post links to get an exact amperage rating

 

[(*steve*)]

It all depends on the power required for the loads (heater and light) and the number of available hours of sunlight, and how far you want to deplete you batteries routinely and/or how many days of reserve power you require (in case of multiple cloudy days)

You might, for instance, calculate your average load as 20W -- which means 480 Watt hours per day. If you want to allow for 3 days of cloudy conditions, that means probably 3 kWhr of capacity in lead acid batteries (since you don't want them to be more than 50% discharged).

Given the inefficiency of charging lead acid batteries, you probably need to have a panel capacity of giving you 1kWhr per day just to run the load, plus whatever you require to provide additional charge to the batteries. Lets say 2kWhr per day.

The size of the panels depends on the number of hours of sunlight, the angle of the sun, etc but let's say it averages out at the equivalent of 5 hours per day. In that case 400W of panels should be sufficient.

This is all back of the envelope calculations. Maybe someone else can provide better answers -- these are very conservative.

 

[donkey]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290360127571&ssPageName=ADME:X:AAQ:US:1123
this is the uv light i am looking at leds.
led wight light also so we can see them properly. the fun comes with a heating pad. i have seen jaycar and they have resistance wire and temperature switches and a heap of stuff.. i just gotta figure out how to put it together.
also they have peltier devices... i might try one of them as they are easier to use, less likely to burn the wood base starting a fire and from memory less power hungry

 

[donkey]

http://www.ebay.com.au/itm/Pack-5-9...Electrical_Test_Equipment&hash=item5d2ddfb18a
ok with these they are 91.2w i was thinking of using all 5. i will run a temperature switch to keep them at a decent temperature so they might use 91.2w for only 12hours... having said that if i get an 18ah battery for example how long will i run this for without recharging and what size panel should i use to charge the battery?

 

[(*steve*)]

12V 18Ah = 216 Wh

Five 90 watt heaters would run for approximately 15 minutes if you wanted to only discharge the battery to 50%

 

[donkey]

wow....that blows huge

 

[donkey]

i thought that thermo electric was a better use of watts than resistive wiring?

 

[(*steve*)]

It doesn't matter how you count your watts, 1 watt is always 1 watt.

I think it's doubtful that you need 450 watts of heating, but that's what you suggested.

How did you come to that estimate of required heating? And how big is this thing?

 

[donkey]

only small.. and the peltier devices are what gave me the watt... it says at the top of the ebay thingy 90 wahtever watts

 

[(*steve*)]

You need to go back to my first reply.

Figure out the amount of heating you require. It may only be a couple of watts.

Then continue from there.

 

[donkey]

ok the small terrarium is going to be heated how to do i figure out the watts needed? i know the size and temperature. and ty to whoever changed the thread title

 

[(*steve*)]

It's very hard to know how much heating is required. It depends largely on the temperature differential and how fast the terrarium loses heat.

It's a question best asked of terrarium experts. Once you know how much power will be required, you probably want a heater rated at about twice that power so that you will have some power in reserve if needed (your thermostat will presumably cycle the heater as required).

And I thought the thread title needed a bit of a tweak

 

[donkey]

well i thought about it and i am now of the opinion that a heating pad/rock would be easiest. the lizards can soak up heat from the pad and move of it when they are warm. still i am assuming that a premade item will be cheaper so will look at finding one. i reference ebay alot but i might find another site to look at soon.