Inverters 12v DC to 230v AC ?

Submitted: Tuesday, Nov 11, 2008 at 21:39

ThreadID: 63446 Views:3642 Replies:4 FollowUps:7

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Member - Jamie M (QLD)

hey guys,

just a quick question or 2. if i were camping and wanted to run a common garden variety household pedestal fan, would a 300 watt inverter hooked up to the hilux (fitted with dual battery system) do the job and if so, for how long before the batteries need charging?

thanks guys.
jamie

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Reply By: Geoff (Newcastle, NSW) - Tuesday, Nov 11, 2008 at 21:48

Tuesday, Nov 11, 2008 at 21:48

Hi Jamie,
Since we don't know the power requirements of the fan we'll base our calculation on the full 300 Watts.

300Watts / 12Volts = 25Amps

Therefore if we assume you have a 100Amp Hour battery that is considered discharged at 50% you'll get a theoretical 2 hours out of the fan before the battery is considered to be totally flat.

If I knew a little more about your setup I could give a more accurate answer.

Hope that helps,

Geoff

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Follow Up By: Member - Jamie M (QLD) - Tuesday, Nov 11, 2008 at 22:10

Tuesday, Nov 11, 2008 at 22:10

thanks geoff,

unfortunately i don't have any more details as i don't own a fan as yet and i really don't have a clue about my setup. i haven't bought an inverter yet but the hilux is set up with the dual system. unsure how much a fan draws but sounds to me like my mrs ain't going to get a fan on her all night tho hehehe.

jamie

FollowupID: 602540

Follow Up By: Geoff (Newcastle, NSW) - Tuesday, Nov 11, 2008 at 22:15

Tuesday, Nov 11, 2008 at 22:15

"sounds to me like my mrs ain't going to get a fan on her all night tho"

Not unless you're prepared to swing a bamboo one for her!

Or you fill the tub of HiLux with batteries!

Geoff

Geoff,

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Follow Up By: Member - Jamie M (QLD) - Tuesday, Nov 11, 2008 at 22:31

Tuesday, Nov 11, 2008 at 22:31

i'll take the bamboo, but i'm filling the tub of the hilux with ice and stubbies.

jamie

FollowupID: 602545

Follow Up By: handy - Wednesday, Nov 12, 2008 at 06:41

Wednesday, Nov 12, 2008 at 06:41

i run a 40 watt fan thru an inverter off a dual batt set up all night and it dosent hurt the batteries at all. cheers

FollowupID: 602580

Reply By: Road Runner - Tuesday, Nov 11, 2008 at 22:19

Tuesday, Nov 11, 2008 at 22:19

Jamie,

Don't think it will be a problem. Very unlikely that your fan will draw the full 300 watts capacity of the inverter - probably closer to 45 watts at 240 volts. The inverter would probably consume another ten or fifteen watts in its operation. Most inverters seem to have a cut-out capability that will disconnect from the 12v supply if supply voltage drops below a specific value (about 10 volts) - this may afford some protection to discharging your battery below the optimum value. A 'techo' would be in a better position to provide you with battery sustainability given your expected current draw.

AnswerID: 334763

Follow Up By: Member - Jamie M (QLD) - Tuesday, Nov 11, 2008 at 22:36

Tuesday, Nov 11, 2008 at 22:36

thanks road runner,

was just searching for the wattage of a regular fan. well that gives me hope i guess. now next question, if the battery/batteries do happen to completely discharge, will they both go or just one? as you can see i don't quite understand the basics of a dual battery system, i guess because i've never needed to till now.

jamie.

FollowupID: 602547

Follow Up By: Road Runner - Tuesday, Nov 11, 2008 at 23:05

Tuesday, Nov 11, 2008 at 23:05

Jamie,

You should probably let an auto electrician look at your dual battery installation. If it has an isolator then only the battery supplying the inverter will discharge. The other battery remains isolated to provide starting capability. If on the other hand an isolator is not fitted, both batteries will discharge.

If you are pessimistic you may care to back up with a solar panel and/or generator with smart charger. Better than extending your stay in the woods!

FollowupID: 602555

Reply By: kcandco - Tuesday, Nov 11, 2008 at 23:01

Tuesday, Nov 11, 2008 at 23:01

Hi Jamie

You may be better to go straight to a 12volt auto fan which although smaller and not able to push as much air will also use less power. I have an old one and it uses about 1 amp per hour. On that basis you could run it for 8 hrs with only a 8 amp total draw per night. other benefits are you are not messing with an unearthed inverter and losing power in the actual inverter itself. I think the 12volt fans go for about 20 - 30 dollars. they are also usually available with an oscillating function like a regular 240 v fan. Also in relation to the dual battery system, make sure the auxillary battery supplies power to the fan and then you dont have the worry of a flat starting battery. This is what dual battery systems are designed for. You can buy a cut out device for about $20 that will disconnect your supply at 10.5 volts or thereabouts but that is draining your battery pretty low so I wouldnt personally go that low.

regards Kc

AnswerID: 334776