When to turn inverter on and off and why?

ThelmaAndLouise

2023 Tab 400 BD 
First attempt at camping without shore power was a failure this weekend. Lithium battery went dead in the first 24 hrs. 

Please explain how and when I need to turn the inverter switch on/off?  I had it on the whole time….

Grumpy_G

You only turn on the inverter for short term 120V needs, e.g. a microwave, a coffeemaker or to charge a laptop. Running the AC will drain the battery in short time. Even with no load the inverter will draw a little bit of energy. 

donmontalvo

Just a thought...if you need to run the AC or Microwave...

https://www.championpowerequipment.com/product/201490-2500w-inverter-with-co-shield/

and

https://www.softstartrv.com/

FTW

PS, I went into boondocking understanding that any notion of running AC and/or microwave off an inverter is woolly thinking.

AnOldUR

donmontalvo said:

I went into boondocking understanding that any notion of running AC and/or microwave off an inverter is woolly thinking.

Not sure when you went into boondocking, but price and availability are starting to make this notion a reality. There's still a lot of room for improvement, but getting 8 to 10 hours of AC run time from 12V is not the pipe dream it was a couple of years ago. A 2000W inverter will run the Air8 without the need for a softstart. Where this all goes in the coming years will be interesting.

donmontalvo

AnOldUR said:

donmontalvo said:

I went into boondocking understanding that any notion of running AC and/or microwave off an inverter is woolly thinking.

Not sure when you went into boondocking, but price and availability are starting to make this notion a reality. There's still a lot of room for improvement, but getting 8 to 10 hours of AC run time from 12V is not the pipe dream it was a couple of years ago. A 2000W inverter will run the Air8 without the need for a softstart. Where this all goes in the coming years will be interesting.

Let's say your 320S has a 12V air conditioner. What happens after the 8-10 hours of run time is over, assuming you don't have a generator, and that it is now dark?

Seems the next day or three (or longer for full time boondockers like me) will be miserable with a dead battery. I mean you no longer have lights, fridge, etc...

In this scenario, how would you keep your battery charged so you don't lose all functionality?

I totally agree about 12V air conditioners existing and getting better...but I stick to my "woolly thinking" comment.

ThelmaAndLouise

Did not use AC. Just isotherm fridge and occasional lighting. 

Marceline

ThelmaAndLouise said:

Did not use AC. Just isotherm fridge and occasional lighting. 

Unfortunately, just having the inverter on consumes power and if you leave it on 24/7 it's enough to make a difference, depending on the size of the battery in your T@B. Since you weren't using AC-powered devices (microwave, air conditioning) it would have been better to just leave the inverter off.

AnOldUR

@donmontalvo
I know you're only trying to make a point, but it would be foolish to run the AC long enough to completely drain the batteries. That's what a shunt is for.

For what it's worth , we just returned from a seven night, no hookup trip testing this newly installed battery setup. We have a 310W panel on the roof, but had poor sun for most of the time. We didn't bother bringing our 400W solar suitcase. Ran our 12V fridge, a small 12V freezer, television, 120V electric kettle for coffee every morning plus lights and misc charging. No need for AC this time of year, but got home with shunt reading 62%.

Like I said, there's still a lot of room for improvement, but even with our current setup, I wouldn't hesitate to run the AC for a few hours to cool the T@B down before sleeping. There'd still be more than enough power to keep everything else running. We mostly dry camp for extended lengths of time, but wouldn't hesitate hitting a campground for a full size shower and charging if it became necessary. 

donmontalvo

ThelmaAndLouise said:

Did not use AC. Just isotherm fridge and occasional lighting. 

Ah, yeah, I installed a 1,200W inverter, hardly ever use it, it is always turned off unless I need it.

donmontalvo

AnOldUR said:

...[snip]...

I know you're only trying to make a point, but it would be foolish to run the AC long enough to completely drain the batteries. That's what a shunt is for.

Agreed...I was responding to your "but getting 8 to 10 hours of AC run time from 12V is not the pipe dream it was a couple of years ago" comment. I guess I took it out of context. :-)

Now that my 320S has 200aH of LiFePO4 and 480W of solar, power is never a problem for me, as long as there is adequate sun. My JLUR has 200W (briefcase) panel to charge it's 100aH LiFePO4, so I can run my Starlink Mini (mounted under the fiberglass top, runs 24/7).

Sometimes I move the 200W briefcase to the camper, if needed. Like when Hurricane Priscilla and then Tropical Storm Raymond slammed me while I was in Utah and Arizona. I was ready with my gas generator (bought it the same day as I bought the camper).

OP, sorry for flying off on a tangent..

ThelmaAndLouise

I have no idea what could have drained the battery.  I did use propane for stove but i don’t think that drained it.   Any suggestions?

pthomas745

@ThelmaAndLouise what exact battery do you have?  (Assuming you have at least a single 100 amp hour lithium battery.

Do you have the Victron app for your solar setup?  Is the Victron solar controller properly set up to charge your lithium battery?

Monitoring and knowing your exact battery status is crucial to successfully boondocking.  Was your battery "fully charged" when you left home?  When you were at the campsite, was the solar setup on the trailer getting any sun on the panels?

The inverter in the trailers is the culprit in many of these types of scenarios.  It is a wonderful device, and gives you the advantage to use "small appliances".  This advantage comes at some cost, of course.  The inverter in your trailer needs power to "make power", and that cost is about 1.5 amps per hour...every hour...just sitting there waiting for a job to do.  If you leave it on, you are constantly losing that many amps, every hour.  Over 24 hours, the inverter can use up 36 of the 100 amp hours of your lithium battery.

The fridge itself, over 24 hours, can use "about" 25-35 amp hours from the battery.  So, those two devices can consume more than 3/4 of your 100 amp hours.  The fridge is pretty much a necessity, and a 100 amp hour battery and decent solar input can/should easily handle the fridge power use. But....that 24 hour inverter use (if that was what happened) put you way behind.

This is all part of the learning curve, and don't feel bad....this happens to many owners, with many different trailers and batteries, for all sorts of reasons. It takes practice.  You have simply had an interesting practice session.

So: do you have the Victron app?  If you are not the original owner, we can help you jump through the hoops needed to make it work for you.

https://www.victronenergy.com/victronconnectapp/victronconnect/downloads

LandVenture

Leaving an Inverter ON will use energy. This can range from 3 watts to double digit wattage. But here is a very important point. Depending on your inverter, the battery output voltage must not fall below a certain voltage to operate the inverter itself. Fall below that voltage and no more household type of appliances are working. BUT maybe just a maybe some 12v appliances 
might work because at 12v output a lithium battery may still have Power. 

I regret to have to tell you this, and I love my nuCamp but their inverter systems are only designed for very short term use. If you are making coffee, I would boil water on the cooktop and use a pour over method. In other words use propane instead of electricity. My home made electric power system is probably 2 to  4 times as potent as what is in most nuCamp and we use it very sparingly. Charge your phones with the 12v power sockets. It’s more efficient. 

Sorry that was long winded. PM me if you want more. 

ThelmaAndLouise

@pthomas745
i do have the Vitron app. In fact, here is a screenshot of whats been happening after getting home and connecting to shore power: 

ThelmaAndLouise

ThelmaAndLouise

ThelmaAndLouise

Binghi

One problem with an inverter is it gets hot when it is turned on and supplying AC power. So it has a fan that turns on to cool it off. And of course, that uses even more power.

pthomas745

@ThelmaAndLouise can you show us the Settings page for your controller?  It will be under the "Cogwheel" on the status page.  It looks like your battery settings are fine...but lets see what they say.

On the history page, each day has a set of "bands" that show the various charging "stages" the battery had entered, and gives a good idea of how much energy the panels delivered.  Going back to days 2/3/4, the darker blue bands show the battery was reaching a "float" stage, which means fully charged.

But, days 1 and 2 show little solar input, and the "max" voltage of the battery dropped quite a lot.  It is the combination of the draw of the inverter and the fridge, along with little solar charging, that "seems" to have caused your loss of battery power over those two days.

Where were you camped?  If you were parked in the shade, solar does not work well at all in those conditions.

Many owners supplement their "roof" solar with portable solar panels that can be out in the sun around the campsite if the trailer is shaded.

BandB

@Marceline this is an interesting thread to me. This is the first I've heard of the practice of turning off the inverter when not needed. Our 2022 320s BD has a WFCO black box on the driver's side bench with a 30, 50, and three 20 amp breaker switches. Is that how we turn off the inverter, by putting those five switches to Off? Or how is it done?

Marceline

BandB said:

@Marceline this is an interesting thread to me. This is the first I've heard of the practice of turning off the inverter when not needed. Our 2022 320s BD has a WFCO black box on the driver's side bench with a 30, 50, and three 20 amp breaker switches. Is that how we turn off the inverter, by putting those five switches to Off? Or how is it done?

Unless someone added an inverter to your trailer, I'm pretty sure that the 2022 320s BD does not have an inverter (DC > AC power). 

pthomas745

@BandB the "inverter" is a separate piece of equipment attached to the battery, and not all trailers have them.  The WFCO is the "converter" in the trailer, and all the Tabs have them.  There is no need to turn the "WFCO" off.

BandB

@Marceline and @pthomas745 thank you so much for the clarification. Now I know more than I did! I really appreciate how you and others help people like me understand our beloved T@bs better.

pthomas745

@BandB you are not the first, or the last, to get lost in the "jargon" of the electrical in the trailer.