New Lithium setup for off grid cruising - and air conditioning

[Whomda]

What smaller AC unit are you considering?

[Networker]

Originally Posted by Whomda

What smaller AC unit are you considering?

Dometic ECD 6k BTU (I have the 16k version of this now). https://www.dometic.com/en-us/outdoo...5?v=9108732762

It says it's only 4.6A consumption, so I assume it's a 4.6AH draw? Seems a bit low, I have to be calculating it wrong.

[Whomda]

Originally Posted by Networker

Dometic ECD 6k BTU (I have the 16k version of this now). https://www.dometic.com/en-us/outdoo...5?v=9108732762

It says it's only 4.6A consumption, so I assume it's a 4.6AH draw? Seems a bit low, I have to be calculating it wrong.

Thanks. 4.6Amps seems very efficient (4.6A at 115V = 530W) -- but boy that 36A startup surge will need some serious soft start!

[kirklkjb]

A standard auto/boat style alternator is not designed to charge a LI system. The large frame Balmar with integral fan and temperature sensing or similar looks like a good suggestion.

[ikanode]

Take anything Will Prosse says with a big grain of salt and research his recommendations. He’s going for page views and not necessarily a balanced, nuanced, and complete presentation.

He has some good info —just don’t make him your only source!

[Networker]

Originally Posted by ikanode

Take anything Will Prosse says with a big grain of salt and research his recommendations. He’s going for page views and not necessarily a balanced, nuanced, and complete presentation.

He has some good info —just don’t make him your only source!

Good point

[Seafarer7]

Originally Posted by Networker

Dometic ECD 6k BTU (I have the 16k version of this now). https://www.dometic.com/en-us/outdoo...5?v=9108732762



It says it's only 4.6A consumption, so I assume it's a 4.6AH draw? Seems a bit low, I have to be calculating it wrong.

You may want to consider the Velair i16 - 16k BTU AC. Being a variable speed drive (VSD) AC you would have the option to run it at a reduced 4K btu, or anywhere up to the full 16k btu, using just 400 watts (up to 900+ watts). The other major VSD benefit is the absence of the startup surge power draw, making it a good fit for running off batteries+inverter and solar.

[mvweebles]

An electric water heater, A/C, electric resistance cooking, plus the normal boat stuff that can easily run 200 AH per day on a non-spartan boat. Asking a lot for a boat-based off-grid system and a small frame alternator.

What works on paper doesn't always work in reality. This is the perfect application for a diesel generator. In the end, a generator for this application would be cheaper, more compact, more reliable, and less maintenance (assuming a high quality generator such as northern lights). Remove need for A/C and resistive heating loads (water heating and cooking), and I love solar.

Best of luck. I hope I am proved wrong here as OP has sunk a lot of money into this.

Peter

[Adelie]

Originally Posted by Networker

Great suggestions. I haven’t made the purchase yet and have also looked at a induction stove top that I can add fiddles and gimballs to. And a breville smart convection oven.

America’s Test Kitchen did a video test counter top ovens. The Breville won by a huge margin on a bunch of cooking factors. I have the model number in my Amazon wish list if you want it. Big enough for a chicken, that’s big enough for me.

[Adelie]

Originally Posted by mvweebles

An electric water heater, A/C, electric resistance cooking, plus the normal boat stuff that can easily run 200 AH per day on a non-spartan boat. Asking a lot for a boat-based off-grid system and a small frame alternator.

What works on paper doesn't always work in reality. This is the perfect application for a diesel generator. In the end, a generator for this application would be cheaper, more compact, more reliable, and less maintenance (assuming a high quality generator such as northern lights). Remove need for A/C and resistive heating loads (water heating and cooking), and I love solar.

Best of luck. I hope I am proved wrong here as OP has sunk a lot of money into this.

Peter

With his indicated list of power demands I would anticipate usage of near 500Ahr/d.

124: AC (530W, 8hr, 35% duty cycle)
75-125: Induction & convection cooking.
0-4/gal: Water heating. solar preheating w/ on-demand could get power demand to zero in many cases.
50: Autopilot
50: Refrigeration
50: Freezer
2.5-5/gal: Water maker. My sense is that Pur is the most power efficient @2.7/gal
50: Nav lights, interior lights, instruments, fans, Laptops
35: Bread maker (I measured this amount for a loaf.)

[mvweebles]

Originally Posted by Adelie

With his indicated list of power demands I would anticipate usage of near 500Ahr/d.

124: AC (530W, 8hr, 35% duty cycle)
75-125: Induction & convection cooking.
0-4/gal: Water heating. solar preheating w/ on-demand could get power demand to zero in many cases.
50: Autopilot
50: Refrigeration
50: Freezer
2.5-5/gal: Water maker. My sense is that Pur is the most power efficient @2.7/gal
50: Nav lights, interior lights, instruments, fans, Laptops
35: Bread maker (I measured this amount for a loaf.)

Given the OP wants all the comforts of home, I think 500AH (6kwh) might be light - you're missing fans and PC/Handheld device charging amongst other things. I really want to differentiate between spartan-cruisers and those who seek a more comfortable power budget to fuel refrigeration/freezer. At-anchor, 150AH is a workable budget. Underway due to electronics and Autopilot, easily rises to 250AH. Add-in electric cooking, A/C, heating water, and a more home-like experience with lights, fan, recharging, etc, and 6kwh doesn't take you very far. Energy loss in the system of 5%-8% for solar, and another 8% for inverter while a constant percentage, becomes a significant factor.

While I admire the OP and certainly wish him well, in my experience both on the water and on land-based solar systems (grid-tie and off-grid), my hunch is his usage will be a fair amount higher than expected; and power generation lower than expected. And the nuisance factor of chasing electrons via monitoring stuff and avoiding shade will be a constant battle. And then there's the expense......

Peter

[Networker]

Originally Posted by Adelie

With his indicated list of power demands I would anticipate usage of near 500Ahr/d.

124: AC (530W, 8hr, 35% duty cycle)
75-125: Induction & convection cooking.
0-4/gal: Water heating. solar preheating w/ on-demand could get power demand to zero in many cases.
50: Autopilot
50: Refrigeration
50: Freezer
2.5-5/gal: Water maker. My sense is that Pur is the most power efficient @2.7/gal
50: Nav lights, interior lights, instruments, fans, Laptops
35: Bread maker (I measured this amount for a loaf.)

That’s about what I’m thinking. Given my solar is maxed at 1420W, I’m still short about 50ah on a good day.

[Networker]

Originally Posted by mvweebles

Given the OP wants all the comforts of home, I think 500AH (6kwh) might be light - you're missing fans and PC/Handheld device charging amongst other things. I really want to differentiate between spartan-cruisers and those who seek a more comfortable power budget to fuel refrigeration/freezer. At-anchor, 150AH is a workable budget. Underway due to electronics and Autopilot, easily rises to 250AH. Add-in electric cooking, A/C, heating water, and a more home-like experience with lights, fan, recharging, etc, and 6kwh doesn't take you very far. Energy loss in the system of 5%-8% for solar, and another 8% for inverter while a constant percentage, becomes a significant factor.

While I admire the OP and certainly wish him well, in my experience both on the water and on land-based solar systems (grid-tie and off-grid), my hunch is his usage will be a fair amount higher than expected; and power generation lower than expected. And the nuisance factor of chasing electrons via monitoring stuff and avoiding shade will be a constant battle. And then there's the expense......



Peter

Perhaps I do but the other 2 300AH batteries and go with 1800AH off the bat. And see how far I can get with a larger alternator or look at wind and hydro, or all 3. That would get me where I need to be it seems.

[Adelie]

Skip either the fridge or freezer.
Get a windvane for steering. It’s not as convenient as an autopilot but the are more robust, use no power and are marginally faster sailing.
Those 2 will save 100Ahr/d
Bread making for me would be every other or every third day so averages to about 15Ahr/d.
Put solar tube out to preheat water.
Insulate you sleeping cabin. I would get a doghouse AC unit which has a higher duty cycle but much lower draw which provides better efficiency.
Put in water storage and only make water when you have excess power or are motoring anyway.

If you try to have all the conveniences of living on land without having to plan ahead some you will be disappointed.

[mvweebles]

Originally Posted by Networker

Perhaps I do but the other 2 300AH batteries and go with 1800AH off the bat. And see how far I can get with a larger alternator or look at wind and hydro, or all 3. That would get me where I need to be it seems.

Because of your hi-current loads, I do not recall a more ambitious solar project on a boat. Usually, people either couple solar with a dose of conservation; or the punt the hi-current items to a generator due to the energy density of diesel fuel which is on board.

I sincerely wish you the best success. Please report back on how it goes - we could all learn a lot from you.

Peter