Hello<br>Will a power inverter draw current from the battery if the unit is turned off?<br><br>I am going to install some onboard 120VAC, I found a 700 watt inverter at Wal Mart, and I used it today, with a temporary hookup.<br><br>Next to make it a permanent installation.

 

Yes it will if it is connected directly to the battery. Without load, it should be a minimal draw but a draw on the batteries none the less.

 

It sure will, be sure to get a good switch to route the inverter power source through. Maybe even something that lights up so you don't leave it on by mistake and drain the battery's down to a no start condition on a cold morning.

 

On my old car I used a wrecked out smart UPS from APC ( you get them at every decent computer store)<br>I had a charge circuit for the internal battery wired to the engine run control relay. So while the engine was stopped I couldn't drain the vehicles batteries. <br>The charging circuit from the UPS was wired to the internal battery and to a relay allowing to charge the vehicle batteries when plugged in. <br>Since the old car was a Toyo Landcruiser diesel with 24V system, I used the Smart UPS 1000 with an internal voltage of 24. <br>I think I'll do about the same thing for the RAM, but will keep as low as 300 VA because AFAIK this is the biggest UPS with 12V internal. <br>The charging circuits of the smart UPS follow th IU line for lead acid batteries very well. In summer I used this to keep the car plugged in and to run the vents without draining my batteries. <br><br>HTH<br>AlpineRAM

 

All the inverters I've ever looked at give the no-load power draw as part of their specs. Usually those figures are rated in milliamps, depending on the inverter size. A 100 amp/hour battery can run a 300 milliamp device for a long time

 

Most good inverters also shut down internally before the battery voltage drops below 11 volts. <br><br>I use on for work in my 96 and leave it on all the time. With no load the draw is less than my bag phone..<br><br>J-eh<br><br>BTW I use StatPower.

 

Have been using a 300 watt inverter and a bag phone for 5 years now, they are always on (I just tend to forget about the inverter - it's strapped under the seat) and have never had a problem.