RecPro 12V RV Air Conditioner

[Judge]

Just got an e-mail from RecPro about their new 12V A/C unit. This looks intertesting and could be a game changer.

https://www.recpro.com/recpro-12v-rv...eid=cc56f21150


Looks like it is capable of 20,000BTU and it draws about 950 - 1100 watts all for the low, low price of $2600!

It does have a 2-year warranty and surprisingly its made in the USA... but the biggest challenge adding it to a coach that is already built will be running the 2AWG wiring to the batteries.

Also does not have a built-in Thermostat. It says you have to wire it into an existing temperature control system in the RV. I would probably add a separate T-stat for it if I was going to install one.

I do have a vent in the front of the coach with no fan in it. Looks like it fits a standard vent opening. It would be easy to installed from that perspective, but it would take some work to run the 2AWG.

[DavidEM]

The reported electrical efficiency sounds like twice that of conventional 120V roof top A/Cs.

But why would you want to install one. 1100 watts would mean almost 100 amp draw on your battery bank. It would take $$$ of lithium batteries to run this A/C for any length of time.

And then comes the real question: How do you recharge those lithium batteries?

David

[Judge]

When you're on shore power, the batteries are out of the equation for the most part so this is really geared for those who boondock more. They are the ones usually setup with the batteries and solar to make use of it.

LiFePO4 prices will keep dropping as the technology matures..... just as solar prices have dropped over the past couple years.

I ran the 5000 BTU A/C unit off my Inverter and stock flooded batteries in my Outlaw 29H and on a good day the solar could keep it going for awhile.

For those who dry camp and want some A/C, this would be a good way to go if they are running lithium batteries and solar.

[DavidEM]

OK, lets run some numbers.

Let's assume the 20,000 btu/hr A/C runs at a 50% load factor in a hot, sunny climate. So at approximately 1,000 watts at 100% that is 12,000 watt hours per day.

A solar panel array on a clear sky, summer day can produce 40 amp hours per hundred watts daily or about 500 watt hours. So it will take 12,000/500= 24 panels or 2,400 watts of panels will be required..

Even a big DP Class A will not have enough roof area for those panels. The battery capacity will be big, particularly if you want them to cover an occasional cloudy day. But the real problem will be enough roof area for the solar panels.

David

[powerboatr]

up to 100 amps of 12volts is a TON of power


its a cool unit, pricey and can take the place of a 120 volt unit


but you need a big battery and strong charging system .




i want a 120 volt compressor up front on my pusher to run the dash a/c. get rid of the 60 feet of hose and compressor out back.

[sportcoupe]

When you are on shore power, this is still a 12v unit and will be running off your batteries and whatever little your charger can output. The batteries are NOT out of the equation.

[DavidEM]

I would install at least a 100 amp charger, preferably more to use this beast with shore power.

Wonder why they didn't design it for 48V DC. You pretty well have to have a dedicated DC system to power it in any case and 48V would sure cut down on wiring size.

David

[Chance]

Originally Posted by Judge

Just got an e-mail from RecPro about their new 12V A/C unit. This looks intertesting and could be a game changer.

https://www.recpro.com/recpro-12v-rv...eid=cc56f21150


Looks like it is capable of 20,000BTU and it draws about 950 - 1100 watts all for the low, low price of $2600!

.....cut....

I see where Ad states that it has a 20,000 BTU/hr compressor, but they don’t actually come out and state what the cooling capacity is.

Other numbers suggest 20,000 BTU/hr is not likely. Perhaps not even close. I would want to see a data sheet before spending that much on this A/C.

Also, the listed outside noise level rating is higher than many generators. I’d want to know how that was measured to compare.

Sorry to sound a little skeptical, but the Devil is in the details, and marketing claims don’t seem to mean as much as in the past.

[Rybie]

Yes, I would like to see details too.

Also keep in mind that it doesn't have to run 100% of the time. So if it ran 50% of the time, 12 hours x 1100 watts x 50 % cycle = 6600 watt-hours. My 400 watts of panels could probably keep it going for an hour a day given a few other drains.

Actually my panels don't keep up with the Whirlpool 120 V frig and the inverter.

[Judge]

Originally Posted by Rybie

Actually my panels don't keep up with the Whirlpool 120 V frig and the inverter.

I have two 160W flexibe panels that are over two years old. I also have (4) 6V batteries at about 200Ah. I have no issue keeping my Whirlpool runnung on the Inverter.... plus the small outdoor kitchen fridge.

What type of batteries do you have and how old arre they?

I'm in the middle of replacing my flooded batteeries with three 170Ah LiFePO4 batteries. I should be able to do much more with the new setup.

[Rybie]

I have two AGM 200ah batteries about a year old and checked out fine, about to add two more.

RV Dealer checked things out and says all is good. In February dry camping on my own i needed to run the generator a little while i used the microwave. I used very little lights or anything else. Last month the wife and I were drycamping and the batteries would die in about 4 hours. I would turn the generator off by 9 pm. During the night i had to turn the inverter and frig off. In the morning the batteries would be back up from the solar and i would start it all over. The fridge pulls 1 amp at home on 110 per my surge protector. That would equal 10 amps at 12v. 200 ah batteries should be good for 200/10 = 20 hours. I use 200 ah because the batteries are each 200 but should only go to 50 % power level.

I checked current on each line and could not find any other draw.

Does the fridge take more power? Am i missing something?

Any help would be appreciated
Rybie

[Rybie]

Another question, why would three batteries with 170 ah capacity be better than 4 with 200 ah?

[Judge]

Originally Posted by Rybie

Another question, why would three batteries with 170 ah capacity be better than 4 with 200 ah?

So Flooded and AGM batteries only let you use about half their actual capacity. If you have a 200Ah battery, only about 100Ah can be used before the battery reaches a discharged state that begins to damage the battery. If you discharge too much and too foten, it will shorten the life of the battery. You also only get ~300 charge cycles before the battery performance starts to drop off. The voltage also drops quite a bit as the battery is used. You typically are at 12V when you are at 50% depth of discharge.

A LiFePO4 battery lets you discharge the battery almost completely and as you dicharge the battery the voltage tends to drop off more slowly. You can discharge down to 80% or use about 136Ah. The voltage will also be about 12.9V at 80% DoD.

With three 170Ah LiFePO4 batteries in parallel I will have 510Ah and be able to use over 400Ah safely. The best part is that if I don't go down below 80% depth of discharge, I will get 5000 - 7000 cycles. That means the batteries could last 5 - 10 years. If I use more than 80% then the cycles drop to about 3000 cycle life but I am using almost the full capacity of the battery.

[Rybie]

I spoke to another service technician and he suggested that maybe i am not fully charging the batteries like i am thinking.

I will make sure they are fully charged and test things again.

Thanks
Rybie

[Rybie]

Yes, I concur with your Li battery , i had not done the math

[LarryD]

are you certain your batteries are 12v? Mine are 6v. 2x 6v @200ah ea = only 200ah @12v. Then @50% usable your left with 100ah of real capacity. That would be in line with what you are experiencing.