Quote:
Originally Posted by Danack
Hi guys,
I'm going to be going travelling in a campervan in a couple of days, and as I'm planning on using a laptop quite a bit I'm thinking of getting a solar panel and battery package like this one, ( http://www.australiandirect.com.au/b...age/PackSol120) which includes this battery ( http://www.australiandirect.com.au/b...ttery/OZOCB120).
I'm hoping you can help confirm a couple of things I'm unsure about.
1) The discharge timings for the battery are:
C1 66, C3 80, C5 88, C10 98, C20 107, C100 122
Am I reading that as the battery would provide 107Ah @12V when discharged in 20 hours - so that would be the case when drawing about 65watts (pre-inverter) from the battery? (107Ah * 12V / 20hours). btw I realise only drawing the battery down to 50% is recommended, but just wanted to check the maths on the provided figures.
2) Does the voltage produced by a deep cycle batteries vary much or are they pretty stable - i.e. is it safe to plug things that are expecting 12 volts into them, or do you need to run them through a regulator. I'm going to get a charger for my macbook that plugs into a cars cigarette lighter socket, to avoid having to use an inverter to charge it, but was wondering if that was going to be ok.
3) How much power would you expect a solar panel rated at 120watts to actually provide on days with reasonable sunlight, and how efficient is the charging process for a deep cycle battery?
4) Does anyone have any experience of buying from Australian Direct ?
tia
Dan |
Hi Dan.
We just got back from a trip around Australia.
I have a campervan, with 2x 80watt solar panels (roof fixed)
These were charging 2x 110 amp hour batteries.
These powered the fridge (on 24x7), lights, water pump and accessories in the van.
(These were additional to the battery to start the vehicle, but the alternator also provided recharge to all three).
We used a 150 amp Pure Sine inverter to recharge phones, wireless modem, camera, and 2 laptops. (not all together).
We had no power shortage issues.
I am told panels produce 80% at best (possibly 50% on average). So in your instance 120watt/12volts x80% = 8amps per hour of sunlight.
I additionally carried a 30amp hour battery a sa general backup, but never needed it for that. I bought that battery from Australian Direct, and Yes I can highly recommend them as a good company to buy from.
In my experience, 12 volt batteries are a stable source of power (more stable than using the cigarette plug in a running car). If your 12 volt adapter is purpose built for that computer, then it is definitely the way to go.
Fully charged the battery will be about 13 volts.
When it is down to 11.5 volts it should not be used.
This range is easily within the tolerance of any 12 volts DC device; or power adapter (where the PC is not itself 12 volts DC input).
In relation to your maths question.
drawing 65watts @ 12 volts = 5.5amps
So in theory yes that equates to about 20 hours.
But as you said, never budget to draw that much, or you will have a dead battery very quickly. Half that would be the maximum I would budget for.
Hope this helps.
