Satori came with a decent setup for keeping the batteries charged from both the alternator and battery charger. She has a Balmar 100 amp alternator plus regulator, and a 20 amp 110 volt charger. The problem I have is simply drawing too much from the small battery bank. Each light would consume over one amp of energy and the refrigerator draws a few amps while it is in it’s cooling cycle, but would run inefficiently from not sealing properly. For a modern tech guy the amount of available amps was not enough to satisfy the needs of the new captain and crew. At first I thought it would be a simple matter of adding a solar system to produce enough watts to fill up the batteries during the day and leave enough to use at night. I set out to find a way to install solar panels on the boat and first tried rigid panels on the stanchions. My frame idea ended up being a failed attempt but fortunately the panels turned out to be defective so I was able to swap them out for a set of flexible panels. Then it was just a matter of having enough canvas facing upwards or outwards to mount three hundred watts worth. This proved to be enough to keep the batteries charged to run the refrigerator and all other components full time during the summer months, when the sun is actually out. Once fall set in I was back to needing to plug in full time while at the marina to keep the system charged due to the lack of direct sunlight and also because I am flying a tarp which covers the solar panels to add more rain and wind protection over the companionway and cockpit. Being off grid is not really required during this time of year, while Satori is getting upgrades and not going anywhere. In order to be confident that she will venture into remote parts of the world without needing to consume gasoline to charge her batteries, she needs a better system. Not just a new charging system but also a new battery bank and wind generator.
There are two flooded six-volt golf cart batteries and have a rating of 235 amp hours. This number is a little bit misleading because it assumes a discharge rate that would never work in the real world. To ensure that the voltage never drops past half of the battery’s capacity I would divide it into half. In other words, you cannot discharge more than half of the flooded battery’s capacity without risking long term damage to the battery. So I knew at the very best that the battery bank could deliver 117 amp hours and assuming a minimum average of three amps per hour at twenty four hours per day would be 72 amps per day. The reserve in the battery would be less than the daily average of required energy and the off-grid charging system could never keep up with this demand without lots of sunlight. There is no room for emergencies, nothing left to ensure that the batteries would last when the sun is gone and there isn’t enough fuel for the generator. The peak demand for me is close to 100 amp hours per day so it’s time to upgrade the system.
Logically the best option for new batteries will be compact 12 volt AGM (absorbed glass mat) sealed batteries. I’ve decided that I will need a minimum of 300 actual (not rated) amp hours, plus a starting battery of at least 1000 cold cranking amps in case she ever has any issues starting and I need to crank long enough to get the engine started. To use AGM, I will need to replace all of the charging systems. That means the solar, engine and shore power chargers will need replacing. The automatic charging relay will need upgrading to handle AGM. I will also need to be able to program the chargers to handle exact voltages at each charging stage instead of depending on the factory settings of the chargers and regulators. Each of the chargers will need a remote battery temperature sensor to make sure that the battery bank temperature never reaches a critical point that may compromise the life of the battery. Each charging system will need to be programmable to set the voltage for each charging stage that meets the requirements of the battery, based on the manufacturer’s ratings. It’s very different than flooded batteries but the benefit will be a greater amount of available amp hours and a much faster charging rate, so batteries will be charged considerably quicker than flooded. Not to mention having newer and more dependable components.
A breakdown of the old and new systems..
START OF OWNERSHIP
- Balmar 100 amp alternator
- Balmar Max Charge MC-512 Voltage Regulator
- Xantrex StatPower Truecharge 20 amp AC charger
- Heart Interface Pathmaker 100 amp automatic charging relay
- Interstate Deep Cycle 12 volt flooded battery with 600 CCA
- Westsail labeled breaker panel with 17 – 15 amp breaker toggles and one 10 amp breaker switch
UPGRADE PHASE ONE
- Sunforce Pure Sine Wave DC-AC Inverter 1000 watts with remote switch
- Renogy MPPT Solar Charge Controller 40 amp with remote interface
- Grape Solar qty 3 – 100 watt flexible solar panels
There are two important factors when choosing an AGM 12 volt system; remote battery temperature sensing and programmable voltage for each charging stage. Each battery manufacturer has a required voltage for bulk, absorption, finishing and float stages. Without these two critical parts the battery bank risks degradation at a much quicker rate. The benefits of AGM are no more lead acid potentially spilling out or corroding the contacts and a depth of charge at 80 percent of it’s capacity. There are several other benefits but these are my favorite. The battery system is likely to stay fully charged more often and can provide enough energy to keep up with the demands of living comfortably in a range of temperatures and conditions. Currently the biggest consumer of electricity is the refrigerator and toilet. The fridge is a necessity for long distance cruising and cycles on and off at a higher rate when the cabin warm up. The toilet usually never peaks above 10 amps and only runs up to ten times at two to three second intervals so it really only consumes a lot of amperes in a short period over a few amperes for a longer period. Both are very important because the first scenario requires a battery than can sustain a long period of draw whereas the other needs enough voltage to sustain the high bursts of energy draw.
To obtain the system that meets the demands of myself and crew, I will be upgrading the charging system, the AC and DC circuits, batteries and much of the wiring. It’s a pretty large project but I am confident that I can complete it within a matter of weeks while taking my time doing everything right. I’ve spent the last couple of months doing an inventory, running calculations and building the upgrade path. Half of the path is circuit and the other is charging. I will be posting updates until the new system is in place and all components are wired, programmed and in service. There is much to learn about marine electrical systems and once I have everything installed I think I will be ready to keep it in premium condition.
Since last year I have managed to take the boat out. I flew the spinnaker on January 1st and then spent last weekend in Port Townsend. Although it’s middle of winter, the weather has been mild enough to enjoy some days out. Showering in a warm and cozy cabin with hot water heated from the stove while baking a chicken in the stove’s oven adds a pleasantry that people do not usually achieve while at sea. I spend a lot of time at the dock so this is a perfect time for interior projects. The winter solstice has passed so we now ascend into better weather, longer days and more time spent outside.