Lithium battery bank question

[Buddy28TE]

Greetings and happy new year,

I am considering setting up a lithium battery bank aboard my 2002 28 Albin. The boat I purchased did not have a generator and my primary objective is to run the air conditioning while we are anchored out. I am wondering from others what might be the minimum amount of watts needed to power the air? I know it seems to range from 2,000 to 4,000 watts. Has anyone else setup a lithium battery bank and inverter. If yes, do you have suggestions on particular battery brands and any other helpful hints? Obviously, I could purchase a portable honda generator but really don’t feel like further polluting the air and causing noise disturbances for anyone else anchored nearby. Thanks in advance for taking the time to read this post.

Have a happy, healthy and prosperous new year!

Shawn Gross
Buddy III
2002 28 Albin TE
Hartge Yacht Harbor
Galesville, Maryland

[Nancy]

The air conditioner manual should list power requirements, but my gut feeling is that you're going to be hard pressed to install enough batteries, even lithium, and a big enough inverter to power the AC at all and certainly for any length of time. Not to mention finding space for that equipment will be tricky. Also, for safety reasons, an inverter can't go in the engine compartment.

I recommend that you try using the boat for a while before making any big decision about whether you need AC at anchor. Most people find they don't, even in the Chesapeake. Open hatches and 12V fans may very well do the trick for you.

[Jkraft]

That AC unit is fairly large for that boat, considering. It’s a 12,000 btu. I am pretty sure they inverter is setup to use lithium as an alternate source but a lot of time and money was invested in making the electrical system on that boat what it is. By time you price up the cost of switching to lithium and the cost of a larger inverter, and considering that I still don’t think you will have the battery capacity you need, your most cost efficient approach would be having a next gen 3.5 diesel generator installed. I did have that quoted a few years back and it was around $12k. One more thing you need to consider with adding battery banks is your charging system. That alternator on the Yanmar is only going to put out so much. If you have a two hour run, it will never charge those batteries back up fast enough to bring them back to usable capacity in my opinion. I agree with Nancy that you should use it for a season first and see how it works. That inverter will run those fans all night.

[furball]

Shawn,
I share your desire to run an A/C off of a lithium battery bank. I would love the quiet it would provide for us and any neighbors in an anchorage. Unfortunately, this is a good summery of what I’ve found.
From someone smarter than me on another forum

“12,000 BTU/hr equals 3517 watts. 3517 watts for 8 hours uses 28.14 kWh of power. Common size for a deep cycle 12V battery is 100 Ah, or 1.2 kWh. It takes 24 batteries of 1.2 kWh size to provide 28.14 kWh.
That’s if the unit is perfectly efficient and runs on 12V DC. Common overall inefficiencies of a compressor, fan and inverter can easily boost that requirement to 35 or more batteries.”

Feel good about not being able to do it that way.
The pollution created by manufacturing that many lithium batteries, not to mention transporting them to you is gonna be way more than anything you can produce from a small honda generator for years to come.
As for the noise, anchor next to us and we can share the scows from the hot sailboats nearby
Congrats on the boat and hope to see you on the water.

John