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Mickey_Finn's avatar
Mickey_Finn
Explorer
Mar 12, 2018

Inverter to charge battery

Hi Very new to truck campers. I have a single 12 volt group 27 lead acid deep cycle in my camper. I have an 1100 watt inverter in my truck(6 cyl Tacoma). If I plug my shore power w/adapter into the inverter and run the truck engine am I charging the battery? How long will it take at idle to charge? Also can I run the fridge at 110? Thanks
  • Mickey, me boy. RVing and electricity are inseparable. Learn, lad, learn.
  • It is the same as utility power. How long does the charge take plugged in at home?

    Otherwise you need to post the model number of the converter in the camper. Generally a low battery takes 3 to 24 hours to get to 90% charged depending on the converter.

    I recommend about 200 watts solar for off-grid camping... assuming you have some sun.
  • Mickey Finn wrote:
    Thanks for the info.. Electricity is a black art to me so I'm a bit confused. I easily ran a 7 cu foot freezer full of fish off the inverter while underway from Alaska to Maine last fall. If the inverter is producing 110 volts/1100 watts, how is that different from shore power? Camper is wired with 3 flat plug for truck. Truck has 4 flat plug for my boat. I can't find any info. about what my truck alternator produces at any rpm's . I plan on mostly boon docking and don't have room for a generator.


    add a front receiver hitch and use a tray to carry the generator up front

    like one of these
    https://www.torklift.com/rv/lock-and-load-sidekick
  • Thanks for the info.. Electricity is a black art to me so I'm a bit confused. I easily ran a 7 cu foot freezer full of fish off the inverter while underway from Alaska to Maine last fall. If the inverter is producing 110 volts/1100 watts, how is that different from shore power? Camper is wired with 3 flat plug for truck. Truck has 4 flat plug for my boat. I can't find any info. about what my truck alternator produces at any rpm's . I plan on mostly boon docking and don't have room for a generator.
  • So you have a regular inverter in the truck and want to plug in the trailer to power it's onboard charger to charge your trailer battery, correct? This will work but is kind of complicated means of doing it.
    Your fridge will pull about 300 watts on 120v AC so that's about 30 amps at 12v coming out of your alternator. If you truck is just idling I don't know how much it will put out but likely not that much. Your camper should have an electric cord that plugs into the truck for 12v power as well as marker lights and maybe signal and brake lights. This cord should allow the truck alternator to charge the battery when running without using the inverter or the camper's charger. If it's not set up that way I would make it that way. You eliminate 2 pieces of equipment and lots of inefficiency and inconvenience.
    Running the fridge on 120v this way is probably less fuel efficient and cost effective than just running it on propane but I guess you could do it if you wanted to. Most people just run them on propane like they're designed to do. They typically cool better on propane than electric anyway.
    It's impossible to say how long this set up would take to charge your battery. Nobody here knows what charger you have in your camper or if your truck's alternator puts out enough power at idle to power it.
  • Unless the inverter ALSO has a charger then it is NOT doing any charging of battery

    With truck running your truck alternator will be supplying a minimal charge to battery......

    Fridge on 110 via inverter....and only one single 12V group 27 battery------NO
  • Ah, Mickey. Think solar, me boy, think solar. Small batteries scream for solar.