Comments on: Power Made Easy – Airship’s Electrical Upgrades

By: Margaret Pommert

Margaret Pommert — Sat, 15 Oct 2016 06:27:00 +0000

Hi Kevin and Laura!
Another great post, thanks so much! As a sailor, I confess a little envy (you have a hair dryer?! and hot water from your 12 volt system?!) But everything you talk about here could be applicable to a cruising sailboat, though obviously the numbers would be different. I really appreciate that you shared what you found as a result of “field testing” so the rest of us have a sense of what is possible. Thanks for sharing!

By: Kevin McLaughlin

Kevin McLaughlin — Wed, 05 Oct 2016 03:53:00 +0000

I installed a battery bank comprised of four Fullriver 250ahr agm’s, six volt, total cost $750. The performance is very satisfactory, price is affordable, but, dang! They are heavy! How I survived cruising on two group 27’s for four summers as a house bank is one of life’s little mysteries. Wait, was it that external alternator regulator the first owner installed?

By: Kevin Morris

Kevin Morris — Wed, 05 Oct 2016 00:32:00 +0000

In reply to Casey Adams.

Hi Casey,

Thanks for the comment/questions!

We got our lithium batteries (and battery management system) from AM Solar in Springfield, OR. Since we bought ours, they have changed suppliers to Victron, I believe. I haven’t had personal experience with Victron, but I’ve heard very good things. Prepare for some sticker shock, though. The price of lithiums is coming down, but they are still VERY expensive compared with AGMs. Our 600Ah 12V array was in the $6K neighborhood. The good news is they are supposed to last much longer (the claims are up to 10x, but I’m skeptical).

Regarding settings for chargers – you definitely need different settings, and most chargers and inverter/chargers do not have a preset for lithium. AM Solar gave us a “cheat sheet” with recommended settings for our Magnum. Basically, you’re bypassing the “3-stage” charging required by AGM/lead-acid batteries, and using the correct voltages for lithium (which are different).

Regarding the refrigeration, agreed! Our refrigerator and deck top freezer are definitely our #2 consumers (after hot water). One correction, though, there is not a 90% loss converting DC to AC. Inverters are typically in the 90+% efficiency range, so there is less than a 10% loss. Our freezer unit is a Frigibar – running on 12V. It’s very efficient for a chest freezer.

– Kevin

By: Laura Domela

Laura Domela — Wed, 05 Oct 2016 00:22:00 +0000

In reply to Tim O'Brien. Oh my gosh Tim, thank YOU so much for your kind comments. I am so glad you enjoy the blog and are following along with us!! It's way more fun to have people to share it with, and hearing that it's educational or entertaining or inspiring is always the best feedback ever. We're so happy to have you along for the ride!

By: Tim O'Brien

Tim O'Brien — Tue, 04 Oct 2016 22:41:00 +0000

Thank you for the greatest blog I have come across! You made my summer lunches at my desk in my office feel like I am on the boat with you!! Such a great read with fantastic details and pictures. In fact, I now also follow Sam after reading about shared adventures! So fun!! Someday my future Nordic Tug will hopefully bring me on these same adventures. Thank you for sharing!!!!

By: Casey Adams

Casey Adams — Sun, 02 Oct 2016 17:58:00 +0000

Great article. May I ask what make/model of lithium batteries you used? Im getting ready to replace my batteries and would like to price them. Are there any other changes I need to make to switch to lithium batteries? Presumably there is a setting on my charger for this battery type.

If you decide to slow die and start spending more consecutive nights at anchor you could improve your energy consumption by having custom refrigeration made by Seafreeze in Bellingham. Refrigeration is probably the second largest consumer after
Your water heater. They make them with 3″ of insulation and very efficient compressor. They made a fridge for me for $3k and it uses 35amps in 24 hrs versus the 95amps of my off the shelf Noca Kool. I was so happy that I had them build a freezer for me for the next year. Even more dramatic than the fridge as I ga since they can build it to run off D.C. Rather than AC like most off the shelf units. That provides a drastic savings in and if itself since there’s a 90% loss just to invert DV to AC.

Anyway, great article. You should consider submitting it to Pacific Yachting. I think many readers would benefit from it and if they publish they’lol pay you $500!

By: Laura Domela

Laura Domela — Sat, 01 Oct 2016 18:27:00 +0000

In reply to Kevin McLaughlin. We've got a 6 gallon hot water tank.

By: Laura Domela

Laura Domela — Sat, 01 Oct 2016 18:26:00 +0000

In reply to GMertl. Thanks Gary. The lowest they ever got was once in Juneau when the dock power went out and we didn't know it...they got down to 17%. Normally for our regular use I don't they they ever dipped below about 40%.

By: GMertl

GMertl — Sat, 01 Oct 2016 18:14:00 +0000

Excellent review and tutorial. I enjoyed reading it and learned some things in the process. I’m very interested in the lithium batteries for my next electrical upgrade. They seem to solve several problems related to lead-acid batteries. I didn’t know 100% of their rating was usable power. In practice, I’m sure you didn’t let them discharge that far though. Did you have a point where you’d recharge (or at least think about it)? Thanks, and I’m sure I’ll refer to this review again many times.
Regards, Gary

By: Kevin McLaughlin

Kevin McLaughlin — Sat, 01 Oct 2016 08:30:00 +0000

Wow, hot water from the twelve volt system! How big is your tank? Somtimes I think an on demand propane hot water unit would be the ticket.