Adding Inverter for dry camping

[jcarlilesiu]

I would like to add an additional battery (have one group 27 now), possibly a solar charging system and an inverter.

I hate that the 120V outlets don't work on battery power. Seems crazy you can't charge a cell phone.

Anyway, I would like to an an inverter. My goal would be to wire it into the system with an automatic transfer switch for shore power/battery power.

Seems awfully involved.

Is the better option adding an inverter with a dedicated female 30 amp outlet on the side of the rv near the front where the batteries are, and simply plug the shore power cable into the inverter when needed?

Seems easy enough, but not "clean". I would really rather add an inverter and transfer switch. Has anybody one that that can explain the process? Does the converter need to stay? Can it go? If the converter is removed, how do the 12V outlets and lights and water pump run? Will they run off of battery power without the converter when on shore power?

Im confused about that one aspect.

[Weyrick57]

I am changing the charger at the rv control fuse center to a lithium charger. Then removing the heavy (75lb) rv battery at the tongue to a 43lb 200ah lithium battery.  Then we I need emergency ac power, I will clip on the inverter cables and plug in the rv power cord.  

Is there sny issue? 

[Grit_dog]

Not sure what you’re actually saying.  
Inverter runs off DC side. 
May want to find some schematic of an inverter install ?

[way2roll]

Given that this thread is almost 9 years old you may want to post this as a new topic. 

[Grit_dog]

I’d say the same except it actually seems the forum sorted old and new posts correctly. Twice now!  Lol

[time2roll]

Shoe2728 wrote:
I have an inverter in my fifthwheel and use it when Dry Camping. I have two batteries in parallel. My question is when plugged in to shore pwr the converter is charging both batteries, the converter is a three stage one and steps down as batteries are charged, now if one battery has a bad cell and cannot fully charge will the converter see this and continue to put out maximum charge and not step down, thus possibly boiling the good battery.

I was trying to find a battery isolater howerver the ones I find on the internet are for use with an alternator and not sure if you can hook the converter to that as a charging source

Converter will have a timer to step down voltage.
Still if you have a shorted battery the battery with a short will boil off the water, get hot and in some conditions explode. It is worth having them tested asap.

[Shoe2728]

I have an inverter in my fifthwheel and use it when Dry Camping. I have two batteries in parallel. My question is when plugged in to shore pwr the converter is charging both batteries, the converter is a three stage one and steps down as batteries are charged, now if one battery has a bad cell and cannot fully charge will the converter see this and continue to put out maximum charge and not step down, thus possibly boiling the good battery.

I was trying to find a battery isolater howerver the ones I find on the internet are for use with an alternator and not sure if you can hook the converter to that as a charging source

[deppeler]

Ron3rd wrote:

jcarlilesiu wrote:
I would like to add an additional battery (have one group 27 now), possibly a solar charging system and an inverter.

I hate that the 120V outlets don't work on battery power. Seems crazy you can't charge a cell phone.

Anyway, I would like to an an inverter. My goal would be to wire it into the system with an automatic transfer switch for shore power/battery power.

Seems awfully involved.

Is the better option adding an inverter with a dedicated female 30 amp outlet on the side of the rv near the front where the batteries are, and simply plug the shore power cable into the inverter when needed?

Seems easy enough, but not "clean". I would really rather add an inverter and transfer switch. Has anybody one that that can explain the process? Does the converter need to stay? Can it go? If the converter is removed, how do the 12V outlets and lights and water pump run? Will they run off of battery power without the converter when on shore power?

Im confused about that one aspect.

Wiring it to the outside with the 30a Receptacle is how I do it and several other members on this forum are doing the same. I power all my outlets with a 300w Samlex inverter, but only use it for the TV's. Works great.

Just remember to switch off your charger, etc as pianotuna noted above.

This is what I want to do...do you have a picture of what it looks like plugged in (to itself) from outside the TT?

[tatest]

Some large and expensive motorhomes use whole-house inverter-chargers that do what you want. 4-10 KW inverters to feed the whole 120v system, autoswitching to mains when connected, and converter-charger section to recharge the battery bank and supply the 12V side when hooked up. Many also provide for auto-start of the generator when battery bank is drawn down. Cummins-Onan has even produced a 'hybrid' sytem in which genset, inverter, high density storage are a single large package, and there are all-electric coaches that use the main engine and a beefed up alternator system for auto-start charging. It is also common to use solar power for charging.

What is common to most of these systems is adequate storage of energy in the battery banks for use through non-charging periods. This would be a lot more than two Group 27 lead acid batteries, smallest systems maybe eqiuivalent of four batteries this size, the more robust eight or more.

You need to understand your energy needs (how much power for how long) to size the storage and charging, and your power draws to size the inverters.

If all you need is to charge a cell phone, power for that can be readily drawn from one of the 12V outlets. Typical draw is 300-500 milliwatts, maybe 1200 for the most power hungry tablets, and they usually charge in less than two hours at that rate. All phone devices work with less than 12V, and the 12V to USB adapters limit voltage to what is needed. No need to invert to 120V AC, then reduce back down to 4.5-6V to charge a phone.

[2112]

mena661 wrote:

2112 wrote:


It would be 120V in parallel.

Yes, it would still be 120V but the 2 sources would be out of phase which would still smoke stuff. I find it simpler still to just plug the shore cord into the inverter.

I didn't! More effort to make the connection and then I have an outside cable (shore cable) hanging.

I can't possibly have both connected at the same time because the only time I use the inverter is when there is no other power and DW wants to watch TV for the evening or run a fan. When I do use it I want to get the inverter off of the battery as soon as I can so I'll have it disconnected before I'm in bed.

[BFL13]

Nothing bad happens right away if you forget to turn the converter off. When I do that, soon I hear the converter fan come on and that reminds me. Oops. The Trimetric shows it too.

[mena661]

2112 wrote:


It would be 120V in parallel.

Yes, it would still be 120V but the 2 sources would be out of phase which would still smoke stuff. I find it simpler still to just plug the shore cord into the inverter. Not possible to smoke stuff that way.

30A receptacle in shore cord compartment


Other end is a 20A plug into the inverter

[2112]

BFL13 wrote:
That seems like you could be on shore power and inverter at the same time making 240v but only if you went out of your way to do that of course.

Is there a reason I would want to make 240V?

It would be 120V in parallel.

Using the shore cord itself to plug into the inverter instead of the extra 120v wire would mean you can't ever get 240v because you can only plug the shore cord into one place at a time (inverter, portable gen, pedestal)

That is what I originally did but I didn't like the shore cord out while in a parking lot. I have clean access into the basement for the cord but I didn't like pulling the cord out of the mouse hole, attach the 20A adapter, having the cord exposed while WM camping, etc. I found it easier to open the hatch, plug in the inverter and done. I have been careful with turning the converter off but I have forgot to turn it back on once.

[BFL13]

That seems like you could be on shore power and inverter at the same time making 240v but only if you went out of your way to do that of course.

Using the shore cord itself to plug into the inverter instead of the extra 120v wire would mean you can't ever get 240v because you can only plug the shore cord into one place at a time (inverter, portable gen, pedestal)

The extra wire may be so the cargo bay door can be kept closed and locked while on inverter. I put a cable hatch in that door to pass the shore cord through to plug it into the inverter. So now the door can stay locked (although every Rver in the world has the key! 🙂 )

[2112]

I took a simple approach on installing my 200W MSW inverter.

The inverter lays in my basement next to my battery. I ran a 12 AWG extension cord from the inverter to the power panel 120VAC side. I cut off the female side of the extension cord and wired it directly to the 120V main. I plugged an unwired cable end receptacle into the male plug so not to have an exposed hot prong dangling in the basement when not in use. It was a simple, inexpensive install.

To activate the inverter I turn the converter breaker OFF, plug the cable into the inverter and connect the inverter to the battery via alligator clips. Now all outlets are energized by the inverter.

It's not automatic but it's simple and functional. Works for us. I never run the MW, AC, coffee pot etc. on it. It's for the satellite, TV, an AC fan and gizmo chargers.