12 volt AC unit

[Steve Hunt]

Originally Posted by posplayr

The model I selected (EAC002.18) was for a wide controllable cooling range (300-800 watts), small size (67x72x16 cm), and lightweight (20 kg). The cooling/heating combo was a plus but not a factor. Specifications vary somewhat with voltage input but cooling for 12V unit is supposed to be about (600-2000 watts) 6824 BTU .

For what it is worth it is a scroll-type compressor.

Does this unit use the standard 14"x14" cutout? I didn't see that info in the link.

[posplayr]

Originally Posted by Steve Hunt

Does this unit use the standard 14"x14" cutout? I didn't see that info in the link.

There are mounting details in the provided manual Page 3

https://www.dropbox.com/s/q4s9qulddd...eligo.pdf?dl=0

This is listed at Alibaba

Applicable minimum sunroof size 300*170mm

This looks like an install video of a similar model from Treeligo posted on Amazon. Mounting look simple and I assume the bars can be shortened to match the opening size. I don't have a hole yet but the roof is pre-formed for a 14"x14" mounting location.

I think I'm limited to 31" horizontally and 36" lengthwise which is 78 cm x 92 cm. There are larger units that are 90x90cm which I just ruled out. As I recall they generally weighed more as well.

https://www.amazon.com/gp/product/B0...N74JAG9Y&psc=1

[posplayr]

3 RV AC Mods to Improve Performance and Reduce Noise

Here is some useful information 1.) improve airflow from a rooftop AC unit as 2.) insulation for the roof top condenser. 3.) Soft start (not needed for a compressor with a Variable Frequency inverter e.g. the Treefoli 12V)

https://www.youtube.com/watch?v=OYMfS5ihDuI

[arctictraveller]

This has been a fascinating discussion, and while I am very happy to see that there are new options arriving on the market, some of the specifications give me a cause for concern. An 80 amp DC draw is very significant. In addition to the initial cost of the units, one may have to also add in the cost to upgrade to lithium batteries if not already done, A larger alternator, and or a DC to DC charger to charge those batteries, the large cabling required to sport that current draw, the weight of the unit on the roof, and the difficulties that may be involved in running large cabling to the roof that moves up and down, and likely several other considerations adding cost to the final unit. Additionally since it’s likely AC shore power will be required to support the 12 V battery system for overnight use, my solution seems to be much simpler. For under $200, and a few hours of fabrication I have 6000btu’s of A/C. Of course, it doesn’t run off of batteries, but for an additional $800 I have a Honda generator that supports the unit nicely. In addition that generator can also be used for other things, like an emergency battery charger should my start battery go dead, or running any other AC loads I see fit. Nevertheless, I am happy to see that more and more options are becoming available.

[posplayr]

Originally Posted by arctictraveller

This has been a fascinating discussion, and while I am very happy to see that there are new options arriving on the market, some of the specifications give me a cause for concern. An 80 amp DC draw is very significant. In addition to the initial cost of the units, one may have to also add in the cost to upgrade to lithium batteries if not already done, A larger alternator, and or a DC to DC charger to charge those batteries, the large cabling required to sport that current draw, the weight of the unit on the roof, and the difficulties that may be involved in running large cabling to the roof that moves up and down, and likely several other considerations adding cost to the final unit. Additionally since it’s likely AC shore power will be required to support the 12 V battery system for overnight use, my solution seems to be much simpler. For under $200, and a few hours of fabrication I have 6000btu’s of A/C. Of course, it doesn’t run off of batteries, but for an additional $800 I have a Honda generator that supports the unit nicely. In addition that generator can also be used for other things, like an emergency battery charger should my start battery go dead, or running any other AC loads I see fit. Nevertheless, I am happy to see that more and more options are becoming available.

I agree. In this comparison of 120VAC solutions to 12/24VDC, the main thing that might drive you to 12/24VDC A/C is off-grid even if partially supplemented by a generator operation. If you already have most of the elements of Lithium then that makes the decision even easier to go 12/24VDC.

However, there is no doubt if you are starting from scratch a Generator and Window 5K BTU air are the cheapest solutions. For a pop top, there are containerized versions and split units where the condenser goes underneath and the head goes somewhere inside but depending upon your existing configuration this may be more complicated than a self-contained window unit.



https://www.sportsmobileforum.com/fo...t-31471-4.html

Originally Posted by posplayr

The current discussion seems to be running far afield and losing track of the original purpose/question. In order to bring the discussion back on track I put together a single figure that focuses on the overall typical RV electrical system and includes most of the relevant options for powering either a 120VAC AirCon or a 12/24VDC AirCon.

I realize I did leave out a solar option, but that just amounts to yet another battery charger and does not change the downstream powering of either AirCon unit.

SUMMARY:
This analysis has been motivated by finding solutions to the market needs and wants for off-grid, NO generator efficient air conditioning solutions for lithium battery operation. On the face of it, using the stated specifications from these two representative AirCon units, the 12/24VDC AirCon seems close to satisfying this market demand. The prices are certainly dropping to the $1000 range and with easy availability from Amazon with extended warranties the risk of purchasing such a unit seems largely mitigated.

In this picture, I tried to layout most of the options.

https://www.sportsmobileforum.com/fo...tml#post320845

[Steve Hunt]

Originally Posted by posplayr

I ordered a Treeligo EAC002.18 from Alibaba. They come pre-charged. Apparently, they are selling out 2000 units per month.

It seems to be the same one as this.

https://www.amazon.com/gp/product/B0...N74JAG9Y&psc=1

Originally Posted by Steve Hunt

I had a bit of a setback. My house batteries (2-100ah Battle Borns) are not being charged by the engine alternator while rolling down the road. After a discussion with Renogy on the phone it seems that the connections between my DC to DC charger, the house batteries and the shunt are not correct. This gets more difficult because the batteries are mounted underneath. So today I'm in the process of dropping the batteries and and putting eyes on what's really happening and what needs correcting. In the meantime, yes can't wait to hear about your unit when it arrives.

-What is the lead-time on your Treeligo?

-I got my wiring issues resolved and am now seeing the engine alternator sending a charge to the house batteries. I have seen anywhere from 6-15 amps charge going to the (2) 100ah Battle Borns. Since getting that sorted I have been testing things everway I can think of to understand how it's suppose to work and how it really works (Renogy 2000w inverter/charger and Renogy 50a DC-DC charger MPPT)... I now have a whole new concern relative to the decision of AC or DC powered roof top Air Conditioner. To recap, my primary reason for looking at DC Air Conditioner was so we could easily run it at a lunch/dinner or any other 1 hour ish type break stop without idling the V10 van engine. However, the most Air Conditioner run hours would be while sleeping (I'm in the Southeast US). Since 200ah of batteries is not going to last all night, I would have to be plugged into shore power/generator so the inverter charger would come on when the batteries got low, top them off and the Air Con continues uninterrupted. In one test after i pulled the batteries down and the inverter/charger kicked in it was cranking out 45 amps to the batteries for 2 hours. The heat the inverter/charger fan was putting off was crazy, 90-95 degree hot air for 2hrs 10mins till the batteries were topped off and the inverter charger shut off. To add that much heat load into the space while the Air Con is working to cool the same space makes me wonder if a DC Air Con is the way to go. The whole van space was 85 degrees and i had the 60/40 doors open. I don't see me adding enough battery capacity to make it thru the night. So now I'm back to considering a AC Air Conditioner. I hate to give up on my original reason for wanting the DC Air Con but i can't think of a reasonable way to get the heat out of the van interior. The good news is that i discovered this before plunking down on a DC Air Con. Any ideas out there???

-The other thing i noticed during the above while the inverter/charger was cranking out 45 amps was the crimp on connector of the output cable from the inverter/charger to the 150 amp breaker was 140 degrees at the breaker lug connection. Its a 4AWG cable and only 20" long. The lug connection at the house battery was 100ish degrees which is maybe 10 ft away. Both lug connections were tight.

[posplayr]

Originally Posted by Steve Hunt

-What is the lead-time on your Treeligo?

-I got my wiring issues resolved and am now seeing the engine alternator sending a charge to the house batteries. I have seen anywhere from 6-15 amps charge going to the (2) 100ah Battle Borns. Since getting that sorted I have been testing things everway I can think of to understand how it's suppose to work and how it really works (Renogy 2000w inverter/charger and Renogy 50a DC-DC charger MPPT)... I now have a whole new concern relative to the decision of AC or DC powered roof top Air Conditioner. To recap, my primary reason for looking at DC Air Conditioner was so we could easily run it at a lunch/dinner or any other 1 hour ish type break stop without idling the V10 van engine. However, the most Air Conditioner run hours would be while sleeping (I'm in the Southeast US). Since 200ah of batteries is not going to last all night, I would have to be plugged into shore power/generator so the inverter charger would come on when the batteries got low, top them off and the Air Con continues uninterrupted. In one test after i pulled the batteries down and the inverter/charger kicked in it was cranking out 45 amps to the batteries for 2 hours. The heat the inverter/charger fan was putting off was crazy, 90-95 degree hot air for 2hrs 10mins till the batteries were topped off and the inverter charger shut off. To add that much heat load into the space while the Air Con is working to cool the same space makes me wonder if a DC Air Con is the way to go. The whole van space was 85 degrees and i had the 60/40 doors open. I don't see me adding enough battery capacity to make it thru the night. So now I'm back to considering a AC Air Conditioner. I hate to give up on my original reason for wanting the DC Air Con but i can't think of a reasonable way to get the heat out of the van interior. The good news is that i discovered this before plunking down on a DC Air Con. Any ideas out there???

-The other thing i noticed during the above while the inverter/charger was cranking out 45 amps was the crimp on connector of the output cable from the inverter/charger to the 150 amp breaker was 140 degrees at the breaker lug connection. Its a 4AWG cable and only 20" long. The lug connection at the house battery was 100ish degrees which is maybe 10 ft away. Both lug connections were tight.

12V lithium it is especially important to maintain your connections. The smallest about of invisible corrosion can cause contact heating at 75+ amps or only 1000 watts.

You should clean (the abrasive pad, spray on DeOcit which has a chemical treatment and then contact paste.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I don't remember what was recommended over at DIY Solar website but there are various products including something like this. This is not what i bought but it is a high grade product that is better than base metal even with the Deoxit prep.

https://www.amazon.com/MG-Chemicals-...00HDF9EXE?th=1


As far as amp hour requirements, this is what I have calculated:

13.2 V 300 Amp-hr
Watts Amps Hours
300 22.72727273 Amps 13.2 Hours
800 60.60606061 Amps 4.95 Hours

300 watts would be ECO and the 800 is full cooling mode. I have not seen any video (for 8K BTU 12V A/C ) yet where the running current load got over 45 amps. The 60 may be a peak start??

The shipping by-sea lead time is a month and we are probably about 1 week into that. There will also be UPS from LA harbor. It seems to have taken 2 weeks to ship. This is B2B at minimum cost so I'm not complaining.

To state the obvious, the feasibility of your use case will be dependent on the AC unit's current draw and how much reserve capacity you have. I have 200 Amp-hr of Lithium and will add 160 amp-hr of Lead Acid to augment that with 40 amp Renogy DC-DC charger. In the worst case, we can run the engine and recharge the battery bank. If running on Eco mode, you get two hours of sleep for each idling hour. Falling back to a small 1000W Generator is also advisable. I will need to upgrade to a 40 amp 120VAC to 12VDC charger.

I'm in Arizona so I'm probably going to build some type of swamp cooler for non-monsoonal (low humidity) cooling. Also with the degradation in the life of lithium at 40 deg C, I'm looking at designing a dual mode (heat/cool) thermal control system using Peliter for a lithium cold plate. Just sitting in the Arizona sun for a month or two is going to accelerate the life and containing the temp range to +30 to 10 degC is going to be a big improvement. See the figure for a concept.

If you can mount the chargers (or even remotely ) to some type of a heat sink and get the heat into the body or frame you have a way to reduce the interior heat gain.

The main intent of these 12VDC A/C units is for parking A/C without idling. So the lunchtime/afternoon rest area parking without having to run the engine is going to be a primary use-case. Unless you have solar you will need to run a generator even if you can make it through the nite. A small generator can run 4 -5 times as long as say my V-10 idling on a single gallon of gas.

I mentioned adding Lead Acid for reserve. Lithium is not something that you want to mount under the vehicle and I will have limited space whereas I can make quite a bit of room for up to 4 LA batteries in the spare tire area.

Connecting these in parallel with the Lithium provides a complementary current supply (at 13.0V Lithium you are not going to deplete the Lead-acid and at 11.5-12.0V on the Lead-acid you are protecting the Lithium from disconnecting. Also, the benefit is that you are protecting the electrical system from load lump in the event the Lithium BMS disconnects.

[posplayr]

I thought I would provide a quick update for anybody still interested.

It has been a while but I did receive this 12V Roof Top Scroll Type Inverter Airconditioned with PTC heating from Treeligo about 11 months ago.

When I received the unit, I opened it up and took the cover off to inspect but honestly thought it would be a hassle to do anything without doing the full install. Time passed...... With the 1 year warranty about to expire I decided to do some testing to ensure it would work.

I have worked out a test setup that allows for the conditioned air to be recycled and get some measurements that I can later be extended to a van install.

I have the AC unit running from a couple of 120 amp-hr AGM's (240 amp-Hr) and backed up by a 10 amp automotive charger (120VAC to 12VDC). The setup is in the driveway under an event canopy (not in direct sunlight).

The AC unit uses only recirculated (i.e. conditioned) air so you need a contained enclosure to get any reasonable temperature readings. In the picture you will see I have a set of storage shelves, split in half with a 20" (on the side) cardboard box (thin material) between the shelf halves containing the conditioned air. I taped off and blocked the box off.

For instrumentation, I have a 3-temperature wireless temp sensor. One of the remote units is in the bottom of the box, the unit also measures ambient, and the third is not used.

The AC has a control display that shows the units thermistor temperature sensor at the top of the condenser just before the blower motor pushes conditioned air into the enclosed space below.

I have a Fluke volt meter on the battery and the unit also measures the voltage at its terminals but suffers some voltage loss after the provided cables.

A clamp on amp meter reads the total 12VDC current to the Airconditioner unit.

There are two openings at the bottom of the unit, one is a return air ports, and the other is the exit for the conditioned air that passes through the vents in the faceplate cover showing in the storage bin (not installed for these tests).

[posplayr]

Originally Posted by posplayr

as far as amp hour requirements, this is what i have calculated:

13.2 v 300 amp-hr
watts amps hours
300 22.72727273 amps 13.2 hours
800 60.60606061 amps 4.95 hours

300 watts would be eco and the 800 is full cooling mode. I have not seen any video (for 8k btu 12v a/c ) yet where the running current load got over 45 amps. The 60 may be a peak start??

I have provided an updated chart to show nominal power consumption at 12.5 VDC.

When in MAX COOL (not at a setpoint just maximum cooling and FAN) the cardboard box got down to 38-39 degrees F with a 77-80 degreeF ambient temperature with teh temperature-controlled backing off from freezing the cooling evaporative core.

When in Heating mode the unit would reach a set point of 31 degC (89 degF) with 10 amps on average for the 20" box (ambient about 55 degree F). Analytically extrapolating this to a 70" on side volume that would be nominally 20 amps average current.

[arctictraveller]

Posplayer, this is a timely update. As I sit here with outside temps below freezing, I’ve been considering my options for this summers travel since my window unit mounted in the rear door has partly failed after three years and no longer responds to the remote. If I’m reading your chart correctly, it looks like there is a maximum current draw of 30 amps when cooling on 12 Vdc. That’s not as bad as I originally thought, and my 200 Ah of lead acid batteries could conceivably run it for three hours or so before reaching a 50% discharge level while a 200ah lithium setup should go double that. I look forward to hearing about your results once it’s installed and operating in the summer heat.