I have a few things I want to do:

 

1. Connect my three 30AH SLA batteries in parallel so that the solar panel controller charges them all at the same time.
2. Move my 40W 12V (which actually puts out more like 20V) solar panel into my greenhouse (easy) or onto my greenhouse roof (more difficult), which will mean a longer cable run. I probably have enough proper solar cable with connectors attached do this, I think.
3. Have my solar panel and batteries run a 12V DC fan in my greenhouse that I got from ebay, using a timer I also got from ebay.

For these I'll need the following

 

1. Four 0.5m lengths of cable (not sure what type / thickness) and appropriate lugs to fit to the battery screw terminals.
2. I might need additional cable to go from the solar panel to the controller. I guess this has to be proper solar cable? How about if the cable isn't exposed to the outdoors, can I use a cheaper cable?
3. 5-10m of cable that can run a 20W fan for periods of up to a few hours. Cable can be subject to sunlight and temperatures up to 40 degrees, and maybe the weather, depending if I drill a hole or go via the eaves.
4. Small lengths of cable to connect things, like the timer to the fan.

I'm currently using 2.5mm, 2 core solar cable, at $4.50 per meter, from sustainable solutions. I wonder if I can get a suitable cable cheaper. I got the fan and timer from ebay cheap, buying in NZ it looks like the cable could be more expensive than the things they'll power!

Can anyone help refine the requirements to the type and size of cables / connectors I need, and where to buy them in NZ? I have found electrical direct, which has reasonable prices for cable, but no lugs as far as I can see. Particularly the lugs, something like this from Jaycar. This is a little side project so I don't want to spend a bunch of money. If it's too expensive I won't bother.