Need input on inverter

[lifecamper]

I have had many sleepless thoughts about this situation. The inverter puts out a pure sine 120V just like shore power would. If I plug the shore power into it there should be no difference than plugging into a pedestal at an RV Park. As the battery level begins to discharge the converter charger will come on and start to add charge to the batteries. I am sure the discharge rate will be greater than the charge rate. I have a remote for the inverter and can turn it off thereby ending all charging/discharging. Unless I'm missing something there shouldn't be a problem. As I go down the road I will make sure the inverter is turned off and the truck will charge the batteries. It wouldn't be hard to put a disconnect switch in the converter charger but why? In the future when I add a solar charger that might create a different situation as the solar would charge the batteries while the inverter ran the 120V to the trailer and if battery level got low enough the converter charger would kick in and also charge the batteries. I don't know if that would cause damage to the solar charger? I would appreciate any good info/explanations.

[JRTJH]

Originally Posted by lifecamper

I have had many sleepless thoughts about this situation. The inverter puts out a pure sine 120V just like shore power would. If I plug the shore power into it there should be no difference than plugging into a pedestal at an RV Park. As the battery level begins to discharge the converter charger will come on and start to add charge to the batteries. I am sure the discharge rate will be greater than the charge rate. I have a remote for the inverter and can turn it off thereby ending all charging/discharging. Unless I'm missing something there shouldn't be a problem. As I go down the road I will make sure the inverter is turned off and the truck will charge the batteries. It wouldn't be hard to put a disconnect switch in the converter charger but why? In the future when I add a solar charger that might create a different situation as the solar would charge the batteries while the inverter ran the 120V to the trailer and if battery level got low enough the converter charger would kick in and also charge the batteries. I don't know if that would cause damage to the solar charger? I would appreciate any good info/explanations.

What you describe is the "perpetual energy machine" and none exist in today's world.

Yes, you will be discharging your battery by using it to power the inverter to run the converter to charge the battery. Just how much battery power you deplete will depend (for the most part) on how efficient your inverter and converter are. But, the rate would probably put you with dead batteries in 3 or 4 hours if you last that long.

The biggest problem with using the inverter to plug in the shore power is that with the exception of powering what you intend to power, you're running a circuitous route from the battery to the battery and all you'll be producing is heat in the two transformers/power regulation circuits that sit between the battery supply and the battery return.

Have you ever heard the phrase, "You can't squeeze blood out of a turnip" ? What you're trying to do is squeeze watts out of empty space. I'd say back to the drawing board. You can't make more energy by using available energy as your only source.

[lifecamper]

OK thanks ....not wanting to make more from less. Just wondering if I should put a disconnect switch on the charger. I have noticed that some inverters have a charger built in. Mine doesn't. If the inverter runs the charger and the charger is putting juice back in the batteries won't that slow down the discharge rate? Kind of a 12-4-4+2= situation? If I put a disconnect switch on the charger then I would just have 12-4-4-4= situation.

[thewhitehat]

I'm not the expert, but I do think you need a couple more elements in your setup there to fully realize your plan, such as a charge controller, and something to generate the energy, i.e., solar panels or windmill on the roof. Click on this link: here which contains much information about batteries, inverters, chargers, and solar energy for boondocking.

[JRTJH]

Originally Posted by lifecamper

OK thanks ....not wanting to make more from less. Just wondering if I should put a disconnect switch on the charger. I have noticed that some inverters have a charger built in. Mine doesn't. If the inverter runs the charger and the charger is putting juice back in the batteries won't that slow down the discharge rate? Kind of a 12-4-4+2= situation? If I put a disconnect switch on the charger then I would just have 12-4-4-4= situation.

In theory you're looking at getting something for nothing. The truth of the matter is the "+2" you're trying to add back in comes from the original 12 you started with, but has to be inverted to 120AC, then converted to 12VDC and then sent back to where it started (in the battery). All of that inversion/conversion uses energy, it doesn't produce energy, so no, it won't help, not even a little bit..... Sorry......

[WaltBennett]

Originally Posted by lifecamper

OK thanks ....not wanting to make more from less. Just wondering if I should put a disconnect switch on the charger. I have noticed that some inverters have a charger built in. Mine doesn't. If the inverter runs the charger and the charger is putting juice back in the batteries won't that slow down the discharge rate? Kind of a 12-4-4+2= situation? If I put a disconnect switch on the charger then I would just have 12-4-4-4= situation.

The ones with a charger usually also have a transfer switch as does mine. I've routed one of the 30 amp legs of my 50 amp shore power circuit to the inverter input first, then the inverter AC output to one half of my AC breaker panel. When there's shore power, the inverter passes most of it through to the AC breaker panel, but uses some to charge my batteries at the same time. It does NOT draw from the batteries unless the shore power goes away. It then stops charging and starts inverting, providing AC to that same breaker panel leg.

I've also totally cut off the old converter. Just don't need it anymore.

[lifecamper]

Alright given that I'm not going to gain anything...will I create any problems by not putting a disconnect on the charger? My inverter does not have a charger. I will add solar in the near future.