Inverter question

Jthulson · 08-27-2018, 07:09 PM

We have a 2017 Miramar 34.4. Does anyone know what runs off the batteries with the inverter when not hooked up to shore power. Specifically are any of the wall outlets live.

TurnerFam · 08-27-2018, 10:38 PM

turn on the inverter, and plug in a small fan or something in each outlet and find out...

otherwise, your breaker panel may also give you a clue

factories rarely wire 'all' outlets in many gas coaches, except for the higher-end models, maybe, but diesels usually have all on the inverter, at least for the last 5 years or so.... it will really depend on the size of your inverter... less than 2000w and you'll probably only have the residential fridge and maybe one outlet circuit run thru the inverter....the rest will only have power when you are plugged in or on the generator.

Diemaster · 08-27-2018, 10:45 PM

i want to know how do they make it so the AC will run off generator or shore power but not the inverter. i realize thats ~150A drain on the batteries (inverter is 2000W) but i mainly use the inverter to power stuff in between the delay between shore and generator.

TurnerFam · 08-27-2018, 10:49 PM

The air conditioners won't run thru or off your Inverter...

A) they are not connected to the Inverter
B) they draw WAY TOO MUCH amperage for the Inverter to handle, OR the batteries to handle, unless you have 24 of them! i.e., the Inverter might handle 2000w, while an air conditioner is around 13,500watts!

though, if you had a 'window' air conditioner, or the type you can roll around on the floor, then they are 120v and will operate off of your outlets. While the inverter might be able to power it, the batteries would last about 5 minutes before you would be replacing them. That's an expensive proposition.

Beau388 · 08-27-2018, 10:57 PM

Quote:

Originally Posted by Jthulson

We have a 2017 Miramar 34.4. Does anyone know what runs off the batteries with the inverter when not hooked up to shore power. Specifically are any of the wall outlets live.

Usually the duplex receptacles at the TVs, the refrigerator, the video control center and the outside kitchen are powered by the inverter on the smaller (cheaper) Thor coaches. The reason is the inverter bypass is 15/20 amps. If you have a Magnum inverter (the larger Thor coaches have them), the bypasses are 30 or 60 amps depending on the inverter model so all duplex receptacles in the coach are powered.

Beau388 · 08-27-2018, 11:03 PM

Quote:

Originally Posted by TurnerFam

The air conditioners won't run thru or off your Inverter...

A) they are not connected to the Inverter
B) they draw WAY TOO MUCH amperage for the Inverter to handle, OR the batteries to handle, unless you have 24 of them! i.e., the Inverter might handle 2000w, while an air conditioner is around 13,500watts!

though, if you had a 'window' air conditioner, or the type you can roll around on the floor, then they are 120v and will operate off of your outlets. While the inverter might be able to power it, the batteries would last about 5 minutes before you would be replacing them. That's an expensive proposition.

My Coleman Mach 15 (15,000 btu) A/C draws 15 to 17 amps (according to the EMS); 17 amps x 120 volts = 2,040 watts. Of course the starting amperage required for an A/C is 3 to 5 times the running voltage but if it is already running 2,040 watts is a good number.

bigben · 08-27-2018, 11:09 PM

Beau388 is spot on but to finitely know - simply do the plug in thing. In our Challenger we also have a receptacle by the passenger seat that runs through the inverter. Works great for us.

PS: Thor does a nice job with making these receptacles available throughout the coach BUT if you intend to use these often suggest upgrading to 4 each, 6 volt batteries should be a priority. We upgraded to 4 Trojan 105s about 2 years ago and are very satisfied. Also because we often dry camp for upwards to 3 months each winter, I installed a Flow-Rite RV-2000 Pro-Fill RV Battery Watering System. Makes keeping the battery cells topped up very easy.

**16ACE27** · 08-27-2018, 11:45 PM

Quote:

Originally Posted by TurnerFam

The air conditioners won't run thru or off your Inverter...

A) they are not connected to the Inverter
B) they draw WAY TOO MUCH amperage for the Inverter to handle, OR the batteries to handle, unless you have 24 of them! i.e., the Inverter might handle 2000w, while an air conditioner is around 13,500watts!

though, if you had a 'window' air conditioner, or the type you can roll around on the floor, then they are 120v and will operate off of your outlets. While the inverter might be able to power it, the batteries would last about 5 minutes before you would be replacing them. That's an expensive proposition.

Don't confuse Watts with BTUs. Not the same thing.

TurnerFam · 08-28-2018, 06:39 PM

I was close though....

PERFORMANCE (Dometic Penquin II)

Cooling capacity....3953 W
Power consumption - Cooling mode .... 1731 W

https://www.dometic.com/en-us/us/pro...uin-ii-_-20669

maybe : )

Chance · 08-28-2018, 07:14 PM

13,500 BTU/hr = 3956 watts, both refering to cooling capacity

1731 watts is electrical power required to operate A/C under test conditions

Chance · 08-28-2018, 07:42 PM

By the way, air conditioners have recently been powered by inverters on many motorhomes from different manufacturers. As an example, the 11,000 BTU/hour Power Saver A/C only draws around 1200 watts or less, and has been powered with inverters as small as 2,000 watts (with 6,000-Watt surge).

The Class B motorhomes I’ve seen could run up to 3+ hours on 400 Amp-hours X 12-Volt lithium batteries. The newer units with greater battery bank capacity can run much longer.

Years ago a few Sportsmobile camper vans could run A/C off Inverter powered by AGM batteries, but were limited to under 2 hours. It was marketed as a way to leave a pet in van while owners left for lunch or quick hike or bike ride.

None of this addresses the OP question, but in my opinion we should not be too quick in dismissing all possibilities of powering air conditioners from batteries. It’s being done, so little doubt that it’s possible with enough money.

The Gritz Carlton · 08-28-2018, 07:52 PM

"It’s being done, so little doubt that it’s possible with enough money."

Those that say money can't buy happiness just don't know where to shop!!

Chance · 08-28-2018, 08:18 PM

Yeah, only takes money you can waste.

I’ve been comparing the Winnebago Travato with an Onan 2.8 kW generator versus the lithium-battery option, and the difference is about $20,000.

The model with lithium battery bank has a 30-Amp (3600 Watt) Inverter that powers the entire coach. At night with cooler temperatures, I’d guess the battery bank may run A/C all night without needing a quick charge. Based solely on specs, it’s an awesome system; if not too expensive. In time we’ll know if other technical issues like using system in cold weather have been perfected enough to mass produce.

Sorry to digress. Back to Thor-size inverters.

TurnerFam · 08-28-2018, 11:44 PM

Quote:

Originally Posted by Chance

By the way, air conditioners have recently been powered by inverters ...
None of this addresses the OP question, but in my opinion we should not be too quick in dismissing all possibilities of powering air conditioners from batteries. It’s being done, so little doubt that it’s possible with enough money.

while true, the OP doesn't have one of the 'units', and therefore the discussion should center around the realities of their onboard systems, not ones for the future... or, start another thread devoted to that specifically. We that have been around the block awhile tend to go a little overboard - I'm sure we've lost the OP several pages ago.

Chance · 08-29-2018, 04:27 AM

Quote:

Originally Posted by TurnerFam

while true, the OP doesn't have one of the 'units', and therefore the discussion should center around the realities of their onboard systems, not ones for the future... or, start another thread devoted to that specifically. We that have been around the block awhile tend to go a little overboard - I'm sure we've lost the OP several pages ago.

I didn't bring up the A/C topic, did I?

I simply corrected some of the misinformation expressed without making it personal; so that others don't read unrelated information and conclude it takes 24 batteries to make an A/C work, or that an A/C can only run on batteries for 5 minutes. I know this probably wasn't meant literally, but many can't tell the difference. If they don't know much about this subject, how can they know if you're serious?

I don't like correcting others at all, but I hate to see bad information go unchallenged even more.

Diemaster · 08-29-2018, 05:05 AM

no i brought up the AC topic because on my rig everything but the AC is powered with the inverter if its on.

i apologize to everyone and the OP for derailing his original question. it was just a "by the way" question.

JamieGeek · 08-29-2018, 11:19 AM

Show me a thread (at least on here) that hasn't deviated from the OP's original question/subject? LOL!

mickeyswartout · 09-05-2018, 09:37 PM

I purchased a used 2011 Thor Fourwinds Chateau 31 and have gone out
in it a couple of times. The first time the batteries showed fully charged
after traveling. But, while plugged in to 30A outlet, the batteries ran down and the Air Unit stopped working. I started the RV and the Air came on and the batteries showed charge. About two hours later, same thing happened.
I thought maybe the batteries were bad. They did look old and I had them
changed out by a RV repair center. Next time out the same issue happened. Why would the Air Conditioning drain the batters if the
RV is pugged in? Is there something wrong or are you suppose to
start the RV and charge the batteries even when pulled in?
I didn't use the lights thinking this may drain the batteries.
Thanks in advance for any advice, Mick

JamieGeek · 09-05-2018, 09:49 PM

The Air Conditioning is 120V AC and doesn't drain the batteries at all.

Did you have the use/store switch in store? When in store the batteries will not charge even when plugged in.

**16ACE27** · 09-05-2018, 10:42 PM

Quote:

Originally Posted by JamieGeek

The Air Conditioning is 120V AC and doesn't drain the batteries at all.

Did you have the use/store switch in store? When in store the batteries will not charge even when plugged in.

Apparently your converter is not charging the batteries. When they die (12 VDC goes away) so does the control power for your thermostat, which shuts down your Air Conditioning. Starting the RV energizes the 12 VDC buss from the alternator.

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