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We've come to the understanding that we are heavy consumers of electrical when onboard. Being able to work from the boat allows us to enjoy our time out on the water more, especially when the weather is gorgeous. We go through about 1,200 watts a day (100amps), every day, as a minimum. The days I work on the boat will have the LTE/WIFI router running, inverter running all day to charge my laptop. We run the hot water heater and shower onboard, which substantially increases our electrical usage. We choose to not run a generator onboard.
I installed/upgraded the following setup:
(I also kept the 20amp battery charger the boat came with).
* Victron Smart Battery Sense (Voltage and temperature sensor) 1 each for House, Thruster and Engine bank.
(The house bank Battery Sense is paired via bluetooth with the MPPT controller for accurate charging from solar).
* A single Lithionics LiFePo4 for my house bank. (320Ah total, of which 270amp-hours are usable).
(The house bank was relocated from port to the center lazarette), and bus bars were installed for equal charge/discharge of the battery bank.)
* Victron CerboGX
I ran a Victron VE.Direct cable from the BMV712 to the CerboGX.
I ran a Victron VE.Direct cable from the MPPT to the CerboGX
I then configured the CerboGX to connect via WIFI to the Internet router for the boat.
The CerboGX will also show me solar and house loads in a single dashboard, watts going in, watts going out.
We are seeing over 2,000 watts a day from our 400 watt solar array on sunny days. I've seen as high as 2.68kwh. Generally speaking, during boating season we don't need shorepower in the Pacific Northwest.
With LiFePo4, they say "all the volts, all the amps, all the time". We run the hot water heater for 45 minutes (about 50amp-hours) and generate enough hot water to take 3 showers onboard. We can run 120volt AC loads (hot water, coffee maker, espresso machine, microwave) down to 20% state of charge.
When the boat is in dry dock at Dagmars marina I leave most things on. We have two refrigerators running and the normal DC loads that run 24x7. I rarely connect to shore power. The boat consumes about 80 amp-hours a day and solar is providing more than that daily. The batteries were back to 100% every day. (It's been full sunny days also).
Solar provides what we need when we're out and about on the boat. For those rainy days, we would conserve electrical as necessary to buy time. I sized the Lithionics LiFePo4 battery to support us for at least 2 days in the dark. Back on the dock, being able to run the 20amp + 60amp battery charger puts 80amps back in quickly while ensuring the batteries are fully re-energized back to 100% capacity, ready for our next adventure.
Incidentally, a full day of clouds and rain in September at Roche Harbor and I still saw 590watt-hours (49amp-hours) of power from a 400 watt solar array.
For anyone looking at their boats electrical, before you upgrade anything, before you buy that portable generator, or that lithium upgrade, start by identifying your requirements first. Everybody’s boat usage is different.
It took us 3 months to sulfate and destroy our house bank on a brand new boat! We used our house battery bank too much for too long. We also put 300 hours on our Yamaha F300 and another 17 hours on the kicker in 12 months. We’ve spent a lot of time on our boat. We upgraded to Lithium because we wanted hot water to take showers while away from a dock.
A battery monitor is essential and would be step 1. It’ll quantify what your usage is. It’ll let you know when you’re approaching empty on your house bank, like a fuel gauge for your battery. From this you’ll be able to easily learn what your requirements are. This is how I know we need at least 100 amps a day, minimum.
Once you know your requirements in how many amps a day you need, then you can evaluate if a solar upgrade will satisfy your needs. If you upgrade your battery bank you will also need to upgrade that battery charger. How big of a battery bank might you need, as that will determine how big of a charger you’ll also need.
Everything on a boat is more expensive. We all joke about that, but electrical work is especially expensive. The wire must be tinned copper to prevent corrosion. All components must be marine grade, no exceptions. Everything must be tied down and connections protected. The marine environment is harsh. Salt in the air will corrode everything. The constant vibration of the boat is like an earthquake that doesn’t stop.
It only makes sense to upgrade to meet your specific boating needs. It’s also quite possible that you don’t need to upgrade anything. It all depends on how you use your boat.
If you've got a RT27-OB NW edition and would like it converted to the Channel Surfing Edition with LFP (LiFePo4), send Martin an email.
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