So we had a dual battery switch installed on our last boat. It was an 18’ sailfish. We wanted to take the boat offshore about 30 miles and wanted the peace of mind that we would have an alternate source of power in case the battery died. We asked when we had it installed what the best way to run it was, and got mixed responses. We were told that some people liked to keep the switch on all so that the motor was always charging both batteries when it was running. Others said that they preferred to alternate between the two each time they ran the boat. We decided that the best thing for us was to keep it on all all of the time so that both batteries were always charged.
Then we decided to trailer the boat to Key West for a week of vacation during the lobster season. We rented a house that was behind sloppy Joes on Duvall street with two other couples. We kept the boat at city marine where it was the smallest boat on a slip. We did the usual tourist thing the first night and got up early the next day to go lobstering. We found a spot that looked good and anchored up to get after some lobster. For a while, 5 of us went lobstering while the sixth person stayed on the boat. After a while everyone but Ann and I got tired of lobstering, while her and I were just starting to figure out how best to work together to catch them. Ann and I became immersed in what we were doing until, at one point I came up for air and noticed everyone on the boat waving frantically at us and pointing toward the shoreline. At that point, I looked up and saw some military police on the shoreline with a loudspeaker telling us we were too close to government property and had to leave. After what seemed like an eternity, I got Ann’s attention and we got into the boat and left. The military police followed us all the way along the shoreline until the island was out of site. That was the last time our friends came on the boat. The rest of the trip, we would be getting up to go on the boat as they were getting in from the nightlife and we would be going to bed as they would be getting ready to go out.
On one of the mornings headed to woman key and began snorkeling for the lobster beneath the coral heads that dotted the area. We would see coral heads and anchor to try it out. If there wasn’t a lot there, we would pull anchor and move to the next patch. During this process, we would only run the engine for about 5 minutes at a time and we were having a blast loading up on lobster. Finally, we got on the boat to move on to the next place and it wouldn’t start. Due to the short running time and the frequent starting and stopping, we had managed to drain both batteries and were now drifting toward cuba. We set the anchor and tried to flag down every boat that came within sight of us and eventually caught the eye of a friendly couple that towed us back into a marina where we were able to get our hands on another battery and were able to salvage the rest of our vacation. From that point forward, there was never a debate….We alternate the batteries on each trip and if we run one too low, we switch to the other and then switch back when the engine is running to get it back to a full charge.
So there you go – If you run a dual battery switch, it is best to alternate between the two and not let both of them drain together.
It was during the time that we were sitting on the boat, dead in the water, that we first said it was “Always an Adventure.”