No more beating around the bush, the time has come to start the big upgrade of the batteries on Nautilus. When the project is complete, we’ll have moved to 640 AmpHours of lithium batteries and a 3KW inverter that will allow us to run a bigger water maker and do our cooking on an electric hob.
As a reminder, there is a quite a bit to change over some of the wiring needs to be upgraded and there are additional safety devices that need to be installed when running lithium batteries. I expect the project to go in phases, with part one getting the batteries, charger / inverter and management system in place.
This is how it all looks before I started......
Time to start pulling things apart....
Happy as a pig in s***. One of the best bits of owning a boat is you can pull things apart and put them back together again. It’s like having a big box of toys. The only problem is that if you make a mistake, it can be very expensive. As you can see, we now have a bit hole where the batteries used to be.
Planning the layout
I’ve decided to put most of the house systems on the back wall of the compartment. That gives more space for the new components and I can leave the engine management systems on the other wall.
First thing todo was to mount the new Multiplus ii inverter to map out the space.
Next up, starting to bolt in the new components
And a few hours of measuring, cutting and screwing later…
I’m pretty happy with the results so far. I’ve managed to get everything in that needs to be mounted and there isn’t much room to spare. I’m going to move heating pipe you can see on the right of the picture as it’s in the way. Next step is a lot more wiring to get everything hooked up and tested. Once i’m happy with all of that it’ll be time to mount the batteries and start comissioning the base system. It’ll then be onto the engine side of the bay to get that all working properly again.
5 responses
You’ll be more than ready for any nautical engineering roles that come up on someone else’s boat
Looks complex but can see you’ve thought all this through.
So just a quick recap for the interested novice here….what was the old capacity you had when and what’s the pros of lithium batteries?
Morning Andy, yup was happy as larry putting all the electrics together.
The upgrade took us from 600amp hours of Lead (AGM) batteries to 640amp hours of lithium. This essentially doubled the usable amount of power we have on the boat and reduced the amount of space and weight the batteries took up. We also needed to match the batteries to our power consumption needs. We want to run “normal” electrical appliances on Nautilus and also cook on an electric hob. With AGM batteries, you are limited on how much current you can draw before you start getting a large drop in voltage.
summary maths:
old: 6 x 100A AGM @ 25KG each (150kg). new: 4 x 160A Lithium @ 33Kg (132Kg)
old: usable energy capacity – 50% (300Ah). new: usable energy capacity – 95% (608Ah)
old: max amps before voltage drops – 150A new: max amps before voltage drop: >300A
With all that in place, we have enough power available to us to be able to run 2 fridges, 1 freeze, make water, heat water and cook on.
We’re still early in the season, so we’re still a bit limited on how much solar energy we’re producing, but we’re getting there!
Dear, searching on the Internet I found your site quite by accident and I really liked it, both pictures from your travels and the blogs about maintenance and improvements on the boat. Otherwise, I am preparing to build a VARDO catamaran designed by Mr. Richard Woods, and as part of that, I am looking for the best solutions for electrical installation on the boat. I must admit that at the moment I have not found a better schematic on the Internet than yours. I think You have greatly improved your electrical system and made it extremely efficient. I have absolutely no intention or ability to build a system of that capacity and so complex but I would use some of your solutions if you don’t mind. I would ask you to send me the scheme you drew by email because the one you posted on your site is less visible, and no labels are visible on the devices and other smaller details, also if you have data on conductor sections, that would be a great help for me.
If you have no time for me and my request, I understand, and no hard feelings.
Sorry for my poor English…
Best regard.
Hi Goran, thanks for your kind message. I’ve uploaded a higher resolution version of the schematic: https://watermarksailing.com/wp-content/uploads/2022/09/Nautilus-Wiring-v.1.1-01.png Hope that helps with your designs.
Thank you very much, Mr. Caspar!
It will help me very much…
Best regard!