Help, Inverter

[Zuts]

Hi Guys,

I have to wait 2 months for my SBIG field unit so I got a 300 watt sine wave inverter and a 26 amp hour battery. However I am only expecting it to last 1 hour on the SBIG coz the peltier cooler will suck a lot of power.

If I run out I could connect the inverter directly to my car battery and leave the engine running.

Is this a really bad idea, i mean will I damage my camera or my inverter.

Hopefully I will get a reply before 8.30pm as then I am off to try :scared:.

Thanks.

[Omaroo]

How much power will the whole affair suck - do you know? If it's any where near 300 watts then you'll be pulling around 22 amps. That's a lot. Considering that you don't want to go below 50%-odd charge, then you're looking at supplying about 40 minutes before saving the battery from harm. You CANNOT let it run flat - you'll kill it.

I take it that you'll be running heaters too.

Running off the running vehicle is probably not a great idea as the alternator will supply the rig about 14.5 volts while the engine is running. Can the inverter take this? Probably. Drawing 20 continuous amps off the alternator is like running a couple of heavy-duty driving lights and a bit of other gear. If your car only has a 50 amp alternator then it's going to be a bit strained I think - but I could be wrong. If it's a larger car then you're probably running a larger alternator anyway.

In short - not a great idea - especially with the car merely idling.

I run a 100AH deep cycle battery. 29AH is a piddler.

[Kokatha man]

Hi Zuts, basically omaroo's on the money 'cept I'd say there'd be little chance of overloading your car's alternator - although you're actually going to be drawing considerably more than 22 amps if your load is around the 300 watts your inverter is rated at. (inefficiencies etc)

What is the load you're pulling with your gear? Notwithstanding, 30 amps or thereabouts shouldn't trouble most modern vehicles if the engine's running - not sure I'm approving of having a car engine running for extended periods though.....still, happy imaging!

[Zuts]

Thanks for the replies, I'll tell you later how it went. Mind you I havnt looked outside for an hour so maybe it's cloudy...

The Inverter cuts out at just under 12 volts I think, fully charged the battery gives 13.8 so the battery should be safe.

Paul

[asterisk]

Its not the voltage, but the amperage you have to consider. Amps are what are needed to start the car. The longer you drain the car battery, the less amps available, even though 12v may still be present