Finally! My Batteries and Inverter Now Run My AC!

[Ronbrink]

22 hours ago, Geronimo John said:

There is a post on our site from another owner that installed one with pictures.  Likely was John D., but I may be foggy on that.

GJ

Gj, thanks for the information provided, much appreciated!

[Ronbrink]

11 hours ago, mountainoliver said:

When I upgraded my batteries from flooded cell lead acid batteries to three Battle Born batteries a few years ago, I also made a few electrical upgrades as well. One upgrade was to clean up/simplify the DC wiring and the other was to add a new 20 amp transfer switch to allow me to run the air conditioner on the batteries by way of the inverter. In the photo the new 20 amp Kisae brand transfer switch needed is on the right and the various wires are labeled. The black wire has a 20 amp plug on it and just simply plugs into the inverter. The two yellow wires (12 gauge wires) are the ones that you’ll need to cut. The one on the right comes from the air conditioner breaker in the power distribution panel and the wire on the left goes up to the air conditioner. The correct diagram is printed on the transfer switch cover. I hope this helps.

 

Thank you, this is the pertinent information I’ve been seeking!

[Ronbrink]

11 hours ago, mountainoliver said:

Something that should be mentioned in running the air conditioner on the batteries is that the older inverter is 2,000 watt capacity and according to the manufacturer it will safely handle 2,000 watts continuously. FOLLOW THE MANUFACTURER SPECS! Something else that should be noted here and may have already been mentioned is that the air conditioner should have the easy start module installed and really no other DC loads or AC loads can be running. Especially no other AC loads as the 2,000 watt inverter will be very close to maximum capacity running the original Dometic unit. Additionally, all of the high amperage DC lugs and connections should be checked to make sure that they are tight. I found one factory crimped lug to very warm while running the air conditioner on the batteries so I needed to re-crimp it. My air conditioner draws on average over 100 amps DC and that is dependent on cabin temperature. As the trailer cools down the DC amp draw goes down a bit (less compressor head pressure).

All of your points are duly noted, thanks for sharing! There have been numerous recent comments on the Oliver FBs recommending diligent inspection of wiring connections, something I will definitely undergo prior to wiring in the second TS. I oftentimes use my smaller genny to run the a/c, which is probably comparable to the 2000w inverter, so I am accustomed to and conscientious of the limitations of my system. Again thanks!

[Ronbrink]

On 8/4/2023 at 10:44 PM, mountainoliver said:

My air conditioner draws on average over 100 amps DC and that is dependent on cabin temperature.

I was confused when reading that the ‘quieter’ a/c replacements draw 10 amps compared to the stock Dometic Penguin ll at 16 amps. I too have a 100+ amp DC draw on battery and understand now that the 10 and 16 values cited are AC amps, thus resolving the confusion. It’s also worth noting the aforementioned 100+ amp DC draw is with the compressor running, otherwise the draw is in the 30+ amp range.  Also, when the 20 amp DC/DC charger is activated my draw values drop accordingly. I recently completed my transfer switch install with the information you provided and all is good running the a/c on batteries now. Thanks for the assistance, much appreciated!

[Ronbrink]

On 9/22/2023 at 1:46 PM, Ronbrink said:

Also, when the 20 amp DC/DC charger is activated

I have since upgraded to a 40A DC-DC charger. 

[mountainoliver]

Concerning the issue of running the Dometic air conditioner on battery power through the 2,000 watt inverter. I realized that I stated that the inverter could handle 2,000 watts load. (I have gone back to my original post and corrected it) Actually the inverter is very similar to a 2,000 watt generator. The Zantrex inverter will run 1,800 watt loads continuously and 3,000 watts surge not 2,000 watts continuously. The Dometic air conditioner draws about 1,600-1,700 watts. The inverter will be at it’s limits so absolutely no other AC loads while running the air conditioner!

Edited June 25 by mountainoliver
Clarification/correction

[jd1923]

Yeah, while prior to an inverter upgrade, we should ALL work an A/C upgrade first! Why in the world do RV manufacturers buy anything from Dometic? I will NOT ever, even for a $10 part! Replace the whole unit first and save the $10. Dometic is like government, less is more! 🤣

[Ronbrink]

On 6/25/2024 at 10:03 AM, mountainoliver said:

Concerning the issue of running the Dometic air conditioner on battery power through the 2,000 watt inverter. I realized that I stated that the inverter could handle 2,000 watts load. (I have gone back to my original post and corrected it) Actually the inverter is very similar to a 2,000 watt generator. The Zantrex inverter will run 1,800 watt loads continuously and 3,000 watts surge not 2,000 watts continuously. The Dometic air conditioner draws about 1,600-1,700 watts. The inverter will be at it’s limits so absolutely no other AC loads while running the air conditioner!

When running the A/C on inverter, I’ve really learned to watch the battery voltage displayed on the Xantrex wall-mounted remote, much lower than the reading displayed via the VictronConnect app for the SmartShunt when under heavy load. Taken yesterday after running A/C for an hour. Looking forward to replacing the Dometic as @jd1923 advocates!

A/C running on inverter.

A/C turned Off.

Edited June 28 by Ronbrink

[mountainoliver]

I am also looking forward to replacing the original air conditioner with a quieter version. Still waiting to find one that works out of the box without me rigging home made fixes to make it operate as it should. A year or so ago I almost purchased a Houghton unit until I found out that they had changed the operating profile. I had wire that color matched the furnace wire, a manual thermostat, I had run a pull wire from furnace to the thermostat area, sealant, etc. all ready. I even had a hoist partially set up to lift the old unit off and set the new unit on. I’m still waiting and looking. The Freshjet unit is one that now looks promising. 

[Mike and Carol]

2 hours ago, mountainoliver said:

The Freshjet unit is one that now looks promising. 

Same here.  This will probably be the last summer for our old Dometic noise maker.

[jd1923]

12 minutes ago, Mike and Carol said:

Same here.  This will probably be the last summer for our old Dometic noise maker.

This would be going from one Dometic to another! I need to do better, and if wiring a relay or something is required, then fine.

Here is an interesting spec of the Dometic FreshJet 3, "4 dB less noise than select rooftop air conditioners." Also, why did Dometic retire the FreshJet 2200? It didn't sell? And "4 dB less" than the Dometic Penguin II is still very noisy.

[jd1923]

On 6/25/2024 at 8:03 AM, mountainoliver said:

The Zantrex inverter will run 1,800 watt loads continuously...

During my test, our Penguin II was pulling just over 1800W after it got warmed up. Battery voltage was very close to 12V and I believe it momentarily hit under 12V which created an error code on the Xantrex. (Our unit only has the remote power switch, not the remote panel, so I could only read data from the SmartShunt).

[Ronbrink]

@jd1923 My power draw is <1400W, perhaps the difference being in the 11,000 vs 13,500 BTU units. I too had my Xantrex 2000 shut down once when the batteries, under load, dropped near 12V; a ‘red’ triangle was displayed on the remote panel, yikes! I never really paid attention to the display voltage reading until that happened, just relied on the SOC per the VictronConnect app; lesson learned! I’m still thinking the Atmos 4.4 will be a satisfactory replacement unit. I know of two owners that have planned installs, awaiting their initial impressions.

[jd1923]

6 hours ago, Ronbrink said:

My power draw is <1400W, perhaps the difference being in the 11,000 vs 13,500 BTU units. I too had my Xantrex 2000 shut down once when the batteries, under load, dropped near 12V...

It is very likely your model being less BTUs and a newer perhaps more efficient design. Our Oliver is a 2016 and the Penguin could be a 2015 model, nine years old. Mine started at about 1400W for a few minutes. It also had an easy-start install in 2018 at OTT. When it got to 1800W, 5 min and about 90 outside, I did see an error code a couple times at 12V, and our Xantrex is also older, and it only has the small LCD readout on the inverter, remote is the ON/OFF toggle only.

Looking forward reading re your Atmos install and @rideadeuce Mike has a mid-July date for installation at the dealer. We'll also read soon of @Geronimo John adding final touches on his Houghton install. I'm going to wait out the summer re an A/C decision, in fact it could be as late as next spring. Even after installation of an efficient A/C system, we need LiFePO4 to make running on inverter a reality. Wonder if an inverter pulls more amps with LA vs. LI batteries? Maybe that's some of the wattage difference too.

[Ronbrink]

On 6/28/2024 at 9:00 AM, Ronbrink said:

When running the A/C on inverter, I’ve really learned to watch the battery voltage displayed on the Xantrex wall-mounted remote, much lower than the reading displayed via the VictronConnect app for the SmartShunt when under heavy load. Taken yesterday after running A/C for an hour. Looking forward to replacing the Dometic as @jd1923 advocates!

A/C running on inverter.

A/C turned Off.

I’m beginning to think there is something wrong with this picture! Specifically, the divide between the Xantrex remote panel’s 12.3V reading and the VictronConnect SmartShunt reading of 12.86V; both taken within seconds of each other while under load running the A/C via inverter. I’ve recently had issue with system shutdown when the Xantrex threshold of 12.1V (recommended setting for Xantrex #02, LBCO Voltage, per Oliver for LFPs), even though my SOC was in the low 70s percentile. I have successfully been able to run the A/C up to two hours in duration without issue, but something seems to have changed. Upon searching the forum, I found where another owner reported a 0.5V differential and community consensus indicated that was NOT a good thing! As I recall, action taken was a hard reboot of the inverter involving total isolation by disconnecting the 12V cables for 3 days, which was reported to rectify said discrepancy. As of yesterday, a total reboot was instigated in hope of resolve. Your thoughts regarding this matter would be greatly appreciated, thanks!

[jd1923]

@Ronbrink it would be interesting to see if the reboot changes the voltage readings. I still do not believe that such a reboot requires days waiting.

When you test after the reboot, connect a quality multimeter at your batteries as a third measurement. I'm guessing the Victron shunt is over-estimating voltage, that the 12.3 may be the better number because the 1400W A/C load (12A) should cause a voltage drop.

Less likely, it could be the other way around, the 12.3 being a bad reading. Yes, these numbers SHOULD be the same within 0.01V, given the heavy gauge and short distance of the battery cables to the inverter.

[Geronimo John]

On 6/29/2024 at 7:39 AM, jd1923 said:

We'll also read soon of @Geronimo John adding final touches on his Houghton install.

Thanks for the segway JD!

I completed the Houghton Humidity Mod (Install Relay) yesterday.  Phase II is to do the thermistor relocation mod,  Should have it done in the next day or so.  Both are required as GSMBear stated in his July 2023 posting.

I'll be posting on what I learnd and thoughts on the Houghton Thread.

GJ