Upgrading the AC/DC System in My Cal31
I retired and moved aboard my 1979 Cal31 in July 2010. I have quite enjoyed the freedom to leave the dock and sail anytime I want and have spent many happy days in local anchorages this last year. However, as the 5 year warranty on my two batteries approached I found myself calling for Vessel Assist to get a jump start more than once.
I have to say, I was not good about checking the water levels on the two group 27 batteries. I had upgraded these from group 24s when I bought the boat and replaced the "clip-on" automotive style charger with a nice 8 amp Redicharger. However, the charger was in the cockpit locker and I seldom checked the gauge. I had a sneaky suspicion all was not well. Also, I had recently rebuilt my windlass upgrading the motor from 700 watts to 1000 watts so I knew I needed more amp hours. Also, I wanted to run my vacuum cleaner while at anchor to clean up all the dirt and sand I was bringing back from my hikes ashore. Finally, a test showed my alternator had given up the ghost and was not charging my batteries.
I had spoken with my boat mechanic and he agreed to work with me on upgrading my systems. His solution was a Xantrex Freedom 1800 charger/inverter. This would charge the batteries at 40 amps using a "smart" three stage charger which varied the amps and volts to give the fastest and safest charge and to maintain the batteries at the correct "float" level. The charger would provide all the necessary DC for lights, etc. while connected to shore power (or my ancient Honda generator) and automatically switch to provide AC, up to 1800 watts, while off the grid.
To power the inverter I upgraded to group 31 AGM batteries. Yeah, no more unstrapping the batteries to check the water levels. The combined batteries give me 204 amp hours or a little over 100 while never going below 50%. I also added a group 24 starter battery connected to the house bank with an isolator so I would never have to worry about starting if I ran the house bank down.
To charge these batteries we installed a Balmar 100 amp charger. This has the added advantage of putting a good load on my little 14 hp Universal diesel so it doesn't run cold - and heats up my water faster! Last, I added a Xantrex LinkLite battery monitor - like a super fancy gas gauge for my batteries. It will tell me the voltages for both the house bank and the starter battery, the input/out amperage, the number of amp hours used and a bar graph showing the percent of charge left.
After three weeks cruising in Channel Islands National Park I feel I have made a good investment (of about three B.O.A.T. units). One thing I know I need to do is replace my 1.5 amp anchor light with a low draw LED unit. I have purchased a small 700 watt microwave which, although I have yet to find a good place to stow it while underway, is a handy device for heating leftovers. I love being able to clean up spills with the vacuum cleaner. I have even used my electrice tea kettle but the draw on this (1500 watts), even for a short time, really draws down the batteries.
The new alternator will, for example, take me from 56% to 92% charge in about a hours running which gives me enough hot water to wash dishes and shave and "french" bathe. The Xantrex charger takes a little longer to bring the batteries up to full but the three stage charge (bulk/adsorption/float) is completely automatic. I love not having to worry about whether I need to check the water level in the AGMs. And knowing the engine will always have power to start is priceless.