|
|
01-29-2021, 12:04 PM
|
#81
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
Ducky,
Does Ford offer alternators that offer more capacity?
Or are you looking in the aftermarket realm?
__________________
|
|
|
01-29-2021, 03:11 PM
|
#82
|
Site Team
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 14,045
THOR #7035
|
Quote:
Originally Posted by dkoldman
Three 200ah batteries in parallel? $2,700 plus tax and no built in heat system
But will it run 15k AC unit for 16.6 hours assuming nothing else is running and unit is efficient
|
You better get a new calculator:
3 x 200 AH = 600 AH
600 AH at 12 VDC = 7200 WattHours: https://convert-formula.com/ah-wh
A 15K BTU AC uses 1500 watts: https://www.ramsond.com/wattage-chart/
7200 WattHours/1500 Watts = 4.8 Hours
You're going to need more batteries and a bigger wallet.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad - Selling
2020 Chevy Colorado Z71 Trail Runner Toad
2024 Chevrolet Trax 2RS - Soon 2B TOAD
|
|
|
01-29-2021, 03:49 PM
|
#83
|
Senior Member
Brand: Thor Motor Coach
Model: 2018 24.1 AXISSIXxSIX
State: Arizona
Posts: 6,735
THOR #13932
|
Under 5 hours is what kills the whole idea if you dont need to buy a replacement generator.
5 hours on the generator or v10 is under three gallons of fuel.
I think I'd rather spend the 9 bucks, 3 times a year, than deal with the $2,700 in batteries and $1,600 in dual alternators.
It's just an alternate alternator thought generated by generator potential failure.
'There are many paths, grasshopper'.
|
|
|
01-30-2021, 12:23 AM
|
#84
|
Senior Member
Brand: Still Looking
Model: Sunstar 29VE Winnebago
State: Texas
Posts: 5,564
THOR #13058
|
Quote:
Originally Posted by 16ACE27
|
I think I may have had 4.6 on my 1st pass, but it did not look right; so I went to my Hewlett Bob Calculator Not sure what I did wrong, but I will tell what I did, and maybe you can point out my miscue
I started with 15,000 Btu
went to website below to convert to Watts.....
https://www.rapidtables.com/convert/...U_to_Watt.html
So I had 4,396 Watts
So 4396 Watt at 120 volts I got 36.6 amps
Assumed 600 ah for the 3 lithium batteries
So 600/36.6 = 16.4 hours
The only thing that I can think of is that I assumed a constant load of 4396 watts and you dropped your power consumption based on normal 15k AC power consumption curve? If true, then I will plea that the Ducky never said he had a energy efficient 15,000 AC unit and because the air is always funny in Arizona it runs at full load and consumes max power 100% of the time
__________________
2019 Sunstar 29ve; Toad Lincoln Navigator; RVi Brake 3 & Command Center; Roadmaster Nighthawk Tow bar & Baseplate; Sumo Springs; Safe T Plus; Onan EC-30 AGS; Vmax 250ah AGM; T-Mobile Internet; H/W Heater / Chassis Disconnect Switches; Southwire Surge Guard 44270 & 34951 w/Monitor 40301; Jet Flo Macerator; Alpine SPE500 Speakers; Visio M21D-H8R
|
|
|
01-30-2021, 02:26 AM
|
#85
|
Senior Member
Brand: Thor Motor Coach
Model: Four Winds 26B
State: Ohio
Posts: 489
THOR #20900
|
Quote:
Originally Posted by dkoldman
So 4396 Watt at 120 volts I got 36.6 amps
Assumed 600 ah for the 3 lithium batteries
So 600/36.6 = 16.4 hours
|
The batteries are being drawn at 12V, not 120V, so you have to multiply the 120V amps by 10 to get the amps at 12V.
I don't know how many amps a 15K AC draws so asked Google and got answers ranging from 11-13 amps after startup. Using a value of 12 amps, that's about 120 amps of load on the batteries (at 12V).
A maximum of 90% of that 600 Ah capacity is usable. If you want good cycle life, it's better to keep it to 80%. That's 480 Ah - 540 Ah usable capacity depending on one's desired cycle life.
480/120 = 4 hours
540/120 = 4.5 hours
If the AC runs for 30 minutes of every hour, that's 8-9 hours. (The actual duty cycle depends on what ambient conditions are, obviously.)
That's assuming there are no other loads, which isn't really realistic.
__________________
2021 Thor Four Winds 26B on Chevy 4500
|
|
|
01-30-2021, 01:18 PM
|
#86
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
All this Math is making my head hurt...
__________________
|
|
|
01-30-2021, 02:07 PM
|
#87
|
Senior Member
Brand: Thor Motor Coach
Model: Axis 24.1
State: Connecticut
Posts: 1,769
THOR #20289
|
I just ordered a pair of WindyNation 100 Ah, Group 31 AGMs for $358 or $179 each including jumper cables from Amazon- https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
That price is close enough to what a golf cart FLA will cost to make it worthwhile, and I can't fit a golf cart battery into the available space anyway. AGM pricing has come down significantly over the last few years.
David
__________________
|
|
|
01-30-2021, 06:11 PM
|
#88
|
Senior Member
Brand: Still Looking
Model: Sunstar 29VE Winnebago
State: Texas
Posts: 5,564
THOR #13058
|
Quote:
Originally Posted by Bob Denman
All this Math is making my head hurt...
|
Well we should probably get away from the numbers and stick with the abc's.
I don't think they factored in the potential gains from efficiency, power factor effects. The ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in + the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA). This should yield apparent power, the amount of power used to run machinery and equipment during a certain period.
But seriously lets view it this way, if my ACs could run off the batteries overnight from dusk to dawn; it would get my attention. If Ducky wishes to install that system in my RV as a prototype, I am willing to make the sacrifice
__________________
2019 Sunstar 29ve; Toad Lincoln Navigator; RVi Brake 3 & Command Center; Roadmaster Nighthawk Tow bar & Baseplate; Sumo Springs; Safe T Plus; Onan EC-30 AGS; Vmax 250ah AGM; T-Mobile Internet; H/W Heater / Chassis Disconnect Switches; Southwire Surge Guard 44270 & 34951 w/Monitor 40301; Jet Flo Macerator; Alpine SPE500 Speakers; Visio M21D-H8R
|
|
|
01-30-2021, 06:30 PM
|
#89
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
Bob has swallowed his tongue in a bizarre suicide attempt...
__________________
|
|
|
01-30-2021, 06:46 PM
|
#90
|
Senior Member
Model: 25.2 Axis
State: Arizona
Posts: 839
THOR #3471
|
Quote:
Originally Posted by dkoldman
Well we should probably get away from the numbers and stick with the abc's.
I don't think they factored in the potential gains from efficiency, power factor effects. The ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in + the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA). This should yield apparent power, the amount of power used to run machinery and equipment during a certain period.
But seriously lets view it this way, if my ACs could run off the batteries overnight from dusk to dawn; it would get my attention. If Ducky wishes to install that system in my RV as a prototype, I am willing to make the sacrifice
|
Put a hamster on your roof
__________________
|
|
|
01-30-2021, 08:37 PM
|
#91
|
Senior Member
Brand: Still Looking
Model: Sunstar 29VE Winnebago
State: Texas
Posts: 5,564
THOR #13058
|
Quote:
Originally Posted by Hugh.vines@att.net
Put a hamster on your roof
|
So far it is working, no special batteries or installation required. And it runs all night long... Only problem is I have to keep checking for water; no it is not maintenance free; and about as much trouble as a FLA battery.
https://media.giphy.com/media/kEKs1J...huBj/giphy.gif
__________________
2019 Sunstar 29ve; Toad Lincoln Navigator; RVi Brake 3 & Command Center; Roadmaster Nighthawk Tow bar & Baseplate; Sumo Springs; Safe T Plus; Onan EC-30 AGS; Vmax 250ah AGM; T-Mobile Internet; H/W Heater / Chassis Disconnect Switches; Southwire Surge Guard 44270 & 34951 w/Monitor 40301; Jet Flo Macerator; Alpine SPE500 Speakers; Visio M21D-H8R
|
|
|
01-30-2021, 08:41 PM
|
#92
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
Are you using a European hamster... or the Polynesian variety?
__________________
|
|
|
01-30-2021, 08:43 PM
|
#93
|
Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
|
Quote:
Originally Posted by dkoldman
.....cut....
But seriously lets view it this way, if my ACs could run off the batteries overnight from dusk to dawn; it would get my attention. If Ducky wishes to install that system in my RV as a prototype, I am willing to make the sacrifice
|
It’s not only possible, it’s being done already.
600 Ah of lithium is quite common on many compact or van-size motorhomes. The main “goal” is exactly what you mention, which is to operate air conditioner 100% off batteries at night without having to run a generator or fast-idle the engine to power alternator(s).
This approach could work with 600 Ah on a larger motorhome if cooling was limited to a segregated bedroom area with one efficient A/C.
The key is to start out with the most efficient air conditioner available and that it be properly sized. For small bedroom areas at night, even an 11,000 BTU/hour A/C is larger than needed at night. A Power Saver at night pulls under 1,000 Watts, and if it operates around 50% duty cycle, it should run all night on 600 Ah.
Having stated the above, some vans like Winnebago Travato are available with over 10,000 Watt-hours useable. And Xantrex is marketing 600 Ah lithium batteries (probably sourced from others), and one with over 1,200 Ah at 12 Volts nominal.
Electrification of motorhome “house” is changing fast; mostly to eliminate generators or reduce their run time.
__________________
|
|
|
01-30-2021, 08:54 PM
|
#94
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
How about a small 5000 BTU unit for a bedroom?
__________________
|
|
|
01-30-2021, 08:56 PM
|
#95
|
Senior Member
Brand: Still Looking
Model: Sunstar 29VE Winnebago
State: Texas
Posts: 5,564
THOR #13058
|
Quote:
Originally Posted by Chance
It’s not only possible, it’s being done already.
600 Ah of lithium is quite common on many compact or van-size motorhomes. The main “goal” is exactly what you mention, which is to operate air conditioner 100% off batteries at night without having to run a generator or fast-idle the engine to power alternator(s).
This approach could work with 600 Ah on a larger motorhome if cooling was limited to a segregated bedroom area with one efficient A/C.
The key is to start out with the most efficient air conditioner available and that it be properly sized. For small bedroom areas at night, even an 11,000 BTU/hour A/C is larger than needed at night. A Power Saver at night pulls under 1,000 Watts, and if it operates around 50% duty cycle, it should run all night on 600 Ah.
Having stated the above, some vans like Winnebago Travato are available with over 10,000 Watt-hours useable. And Xantrex is marketing 600 Ah lithium batteries (probably sourced from others), and one with over 1,200 Ah at 12 Volts nominal.
Electrification of motorhome “house” is changing fast; mostly to eliminate generators or reduce their run time.
|
I was part of a Winnebago Owners new product survey and they were getting feedback on RVs like mine that were made camp ready. Lithium batteries to run everything high on the list. Sumo Springs also caught my attention. It was enough to push me off the fence to invest on my Sumo Springs.
I will probably back track my tough talk and keep checking my water levels on my floods so they do last as long as possible. Maybe by then I can get all I need in Lithium for under $600. If not between the Duracell Ultra AGM and the recently posted Windy Nation AGM; both for $179/ea is likely my next step for 12v Battery supply.
__________________
2019 Sunstar 29ve; Toad Lincoln Navigator; RVi Brake 3 & Command Center; Roadmaster Nighthawk Tow bar & Baseplate; Sumo Springs; Safe T Plus; Onan EC-30 AGS; Vmax 250ah AGM; T-Mobile Internet; H/W Heater / Chassis Disconnect Switches; Southwire Surge Guard 44270 & 34951 w/Monitor 40301; Jet Flo Macerator; Alpine SPE500 Speakers; Visio M21D-H8R
|
|
|
01-30-2021, 09:32 PM
|
#96
|
Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
|
Quote:
Originally Posted by Bob Denman
How about a small 5000 BTU unit for a bedroom?
|
Efficient ones with EER of 12.2 require just around 410 Watts at rated weather conditions. At night conditions it should be even lower.
A small bedroom like on an Axis 24.1 could be cooled at night with less than 5,000 BTU/hr, particularly if motorhome had dual-pane windows, greater insulation, etc.
Design has to be integrated so it makes sense and minimizes costs. It’s not just about throwing more money at batteries (although that may be best option when retrofitting an existing motorhome).
There are now window A/C units with inverter technology that have EER of 15. That’s what we need in an RV rooftop air conditioner. The other promising technology is Direct Current air conditioners which avoid inverter inefficiency. Unfortunately some are not very efficient, and most are very expensive. Just give it a little time like 12V DC refrigerators and competition will force prices down.
__________________
|
|
|
01-30-2021, 09:36 PM
|
#97
|
I Think We're Lost!
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 22,195
THOR #8860
|
Doing more with less: Priceless!
__________________
|
|
|
01-30-2021, 09:43 PM
|
#98
|
Axis/Vegas Enthusiast
Brand: Thor Motor Coach
Model: Axis 24.4
State: Michigan
Posts: 9,837
THOR #1150
|
Quote:
Originally Posted by Chance
Efficient ones with EER of 12.2 require just around 410 Watts at rated weather conditions. At night conditions it should be even lower.
A small bedroom like on an Axis 24.1 could be cooled at night with less than 5,000 BTU/hr, particularly if motorhome had dual-pane windows, greater insulation, etc.
Design has to be integrated so it makes sense and minimizes costs. It’s not just about throwing more money at batteries (although that may be best option when retrofitting an existing motorhome).
There are now window A/C units with inverter technology that have EER of 15. That’s what we need in an RV rooftop air conditioner. The other promising technology is Direct Current air conditioners which avoid inverter inefficiency. Unfortunately some are not very efficient, and most are very expensive. Just give it a little time like 12V DC refrigerators and competition will force prices down.
|
Seems to me it wouldn't be that hard to retrofit the 12V compressor from an EV (unless it runs off of the HVB but I doubt it since many are also used on ICE vehicles).
|
|
|
01-30-2021, 10:12 PM
|
#99
|
Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
|
Quote:
Originally Posted by JamieGeek
Seems to me it wouldn't be that hard to retrofit the 12V compressor from an EV (unless it runs off of the HVB but I doubt it since many are also used on ICE vehicles).
|
There is already the 20,000 BTU/hr unit with claimed very high EER rating, but it’s large and expensive. There are lots of Euro small units, but they are not all very efficient and are expensive.
If I was going to tinker, I’d try to add the inner guts of an inverter window unit or mini-split into a rooftop RV A/C.
I’m looking forward to see what Everchill comes up with for a smaller 12V air conditioner. Variable speed/capacity is needed in any case.
https://rvbusiness.com/way-debuts-ev...ng-open-house/
__________________
|
|
|
01-30-2021, 10:45 PM
|
#100
|
Senior Member
Brand: Thor Motor Coach
Model: 2018 24.1 AXISSIXxSIX
State: Arizona
Posts: 6,735
THOR #13932
|
It would take very little work to put a window unit into the rear basement of a 24.1.
Intake through the bottom of the coach, cooled air into the coach from under the beds or where that bottom drawer is between the beds.
Or
It would sure fit nicely in that space between the frame UNDER the rear basement.
Or
If you can do away with the generator it would fit in that space.
I'll say three hours install time.
Mini split?
Maybe just as easy.
22 seer is what some zwear to....
There's a guy on youtube who says he can run his minisplit 24 hours a day during a quartzite summer on battery and solar.
|
|
|
|
|
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
|