After my solo voyage to seven continents and around the world, I wanted to upgrade my battery capacity and recharging speed to avoid using the generator so much. With the available space for batteries on Phywave, the only way to do that was to replace my existing AGM batteries with lithium batteries and associated monitoring and control equipment.

I was reluctant to make such a major change in the electrical system ahead of a demanding Arctic voyage. I gave the contractor a strict deadline of June 1 to complete the work which actually included replacing all the battery boxes. Even though the lithium batteries were advertised as the same Group 31 size as the AGM batteries they replaced, because of the lifting handles they actually aren’t. I had them install three 300 Ah Epoch heated batteries for a total new capacity of 900 Ah compared to the 440 Ah capacity I had before with the Victron AGM batteries. I also had them install two new dual use 125 Ah AGM batteries as start batteries but with a crossover switch that would allow me to use the start batteries for the house loads if the lithium battery bank failed for some reason.

In addition, they replaced my Victron invertor with a Victron Multiplus that serves as an invertor and a battery charger. Since this is now basically a Victron system, they installed a Cerbo GX communications hub and a GX Touch 70 display/control to monitor and configure it all. To their credit, they completed all the work the Friday before my June 1 deadline.

After I got underway I noticed some quirky things. The Epoch batteries have their own internal Bluetooth connection to an Epoch app. The state of charge shown on the app was much lower than on the Victron GX. Fortunately, the Victron system can also be remotely accessed, in my case, via Starlink. When I explained the problem to the contractor, they were able to remotely adjust the system so the state of charge shown on the Victron more closely matched (within a few percent) the charge shown on the Epoch app. That problem was resolved.

The second problem arose when I tried to charge rhe batteries with my generator through the Multiplus. My 6 kW Northern Lights AC generator essentially mimics shore power in my system. It was only charging at about the 100 Watt level, not nearly enough to recharge the batteries. It should be charging at the 2 kW level, essentially all the charge current the Multiplus is capable of sending to the batteries. When the generator wouldn’t charge the batteries I tried to turn the engine on to charge them. That’s when I discovered there was no seawater flow cooling the engine (as described in Part 1) so I had to shut down the engine. I was far offshore in the fog with no effective way to charge my batteries and keep the navigation system, radio and auotopilot running if the battery charge got too low. Not a good thing.

Thankfully, by remote control the contractor was once again able to step in, assess the generator charger problem, and come up with a fix a day later by having me go through a sequence to completely reset the Multiplus.

So as I write this the new lithium battery installation appears to be working OK, but given the problems I experienced, I’m wary of it. At least the installers are able to remotely help if new problems arise.