Newbie trying to set up Megawatt for charging

Great. It sounds like you had the Megawatt output shorted. It's good to know how well it can take the abuse.

Enjoy your trip

SUCCESS! IT's working!! Thanks Tom M and 2112 and MEX, I had the megawatt connected to the wrong battery terminals. I switched those around and got 13.6 volts across the two batteries and my LCD amp/voltage meter that's connected to megawatt is now working.

Off to Mexico Tuesday morning.

I would hazard a guess power is not getting to the batteries. Disconnect leads both of them from the batteries. Batteries, not some obscure "I think these are connected to the batteries" junction. Then re-test.

And connect the Megawatt as such

It sounds like your batteries are connected properly, but your Megawatt is connected to the wrong battery terminals. Connect to the positive of one battery and to the negative of the other battery.

Need to check that battery wiring

if series they are 'end to end' backwards

or in parallel even backwards

but even if parallel properly for 6v, they make a low resistance short to megawatt
14v trying to charge 6v

I have thought about this, but the lights in the camper and everything else 12 volts works.

I have pos+ to Neg+ connected together of the two batteries and then pos+ from camper to pos+ battery terminal, same for Neg.

I also show 13 volts inside camper according to my Trimetric and solar charge controller.


I am going to check things over in the morning in the light of day. I was hoping to leave for Mexico on monday.

When I check the voltage of the batteries, across the positive terminal on one battery and negative terminal on the other battery I get 0.02 volts, but when I check the battery individually out of the camper they show 6.2 volts

Need to check that battery wiring

if series they are 'end to end' backwards

or in parallel even backwards

but even if parallel properly for 6v, they make a low resistance short to megawatt
14v trying to charge 6v

I am checking the battery voltage across the series link and getting the 0.02 volts. checking a single battery reveals what I would expect 6.2 volts.


Switch on the side is set to 110 volts.


Still confused why I get 2 volts checking the megawatt terminals with it hooked up to the batteries but when its ON but not hooked up it shows 14.8 volts like I would expect.

Also my little cheap LCD volt/amp meter I have hooked up to the megawatt works when the Megawatt is on and not connected to the batteries but doesn't come on when connected to the batteries.

I have been using standard hand held multi meter for all my tests.

On the starboard SIDE of the unit is a slide switch.

110/220