This entire spring, I have been dealing with electrical power issues, of course, like usual, mostly self-imposed. My Kadey Krogen 42 is a really well designed, well-built boat, but for the nut behind the wheel, all would be perfect.
This is what’s been happening.
Batteries. My four Yuasa 8D Sealed Lead Acid batteries, bought in Ireland 4 years ago, are shot. Each battery is 225 amp-hours (AH) but are down to about 10 AH each! That means that once 40 AH are out of the entire bank, the voltage crashes to under 11 volts.
Last fall and again this winter, hoping it was just one battery gone bad, pulling the others down, I separated each battery, let them rest and then checked each voltage. Normally it’s a good sign that they were all within a couple of hundredths of a volt, but in this case, it just affirmed that the entire bank was shot.
My first solution was to get and install an Automatic Generator Start (AGS). I found a Magnum on Amazon. An AGS starts the generator automatically at a certain voltage, in this case 12.0 volts. Once this was up and running, at least I didn’t have to wake up every three hours, check the voltage, go back to sleep for an hour or two, then get up to turn off the generator.
Now, the gen would come on automatically, run for the time I had set, in this case one hour. That would put enough charge back in the batteries for the next few hours.
The installation was relatively complicated because of my Westerbeke gen. It required using two additional relays (the AGS itself is essentially three relays).
About his time, somewhat unrelated to the batteries, I managed to short out my Heart Interface b y doing something really stupid.
We were connected to one 30-amp shore supply. To make life easier, I installed a jumper breaker switch so that I could power both circuits of the boat from the one source. It does mean we must manage our use, so if making hot water in the electric kettle, we must turn ff the water heater which itself uses 10 amps of 120 power.
I managed to blow up two of the mosfets in the Heart inverter by forgetting to disconnect this jumper or disconnecting the shore power, when I went to start the generator.
So, I was also in the market for a replacement inverter. I wanted a pure sine wave inverter to be able to run by 120v heating pad on my bed.
I ended up deciding on MPP Solar Inverters, I got two 1,000-watt inverters that normally run in parallel and thus provide 2,000 watts as needed. I can also sun them singly, giving me back up if needed. Also integrated into each unit is an 80 A MPPT solar panel controller.
On the battery side, I decided to try ONE LiFePO4 chemistry battery, that I would put together myself using four 3.2-volt cells (each 200 AH) and a Battery Management System (BMS). Total cost for the four cells, shipping and BMS was $600, though it took two months by boat from China to Seattle, then barge to Wrangell, Alaska.
The battery was relatively easy to set up. I’d spent much of the winter watching Will Prouses’s videos on YouTube and reading his forum.
Update: the link to one of his videos and forum. Will Prouse’s channel
From the forum, in the marine section, I found the solution to the issue of an abrupt battery shutdown by the BMS, possibly blowing up the diodes in the Alternator or Generator.
The easiest solution seems to be to keep lead acid batteries in the system. So, in my case, I took out only one of the 8D’s and replaced it with the Lithium battery.
The new setup has been operational since June and has worked well and as anticipated.
I had to set a user custom charging program for my Balmar ARS-5 regulator. I also added a temperature sensor for the regulator to know the temperature of the alternator. I set the bulk charging to 60 amps and 120 minutes at 14.2 volts. Absorption I set to the minimum 6 minutes and Float to 13.3 volts.
Works like a charm. If we are on the hook, 12 hours overnight uses about 110 to 150 AH. Once we get underway, the alternator will put 60 amps into the batteries for the first two hours, then go to Float. LiFePO don’t like being kept fully charged, so the Float at 13.3 keeps them about 85 to 90% capacity while underway.
The MPP Inverter/charger works somewhat the same, but at least for now, though I did have to change the Bulk charging voltage from 14.2 to 14.6 volts to get it to go into Bulk charging if the batteries are at 50% since the voltage at 50% stays relatively high at around 13.00 v.
With this set up, now when out fishing for the day for days, we just run the generator for an hour or two in the morning and maybe one hour in early evening.
Next up, our summer fishing trip.
Dauntless at Sea 