The Mystery of the Three Amps

The picture of the alternator kind of gives it away.

The morning after we transited the Canal I woke up and checked the percentage on our batteries. It's just one of those habits on a boat that goes along with drinking coffee and wishing I could read the newspaper. But that particular morning I got a nasty surprise. Our battery levels were down to 75%, which made no sense. We had fully charged batteries the night before from staying in the marina and motoring for a full eight hours.

Now, Vlad had adjusted our Xantrex battery monitor, which reads how many amps are coming in and how many are going out, and had mentioned that it might look like we were using more energy. But 25% in one night?? I was flabbergasted.

Vlad told me not to worry, that the new way of measuring our power coming in and going out would look more dramatic. He also said that it seemed a little high to him too but that it was probably the fridge recovering from all that use during our transit.

However, the next day we were down to 50%, and instead of flabbergasted I was livid. This sucks, I thought. We're going to have to run the generator every night, which is loud and expensive. If it's just a different rate of measuring, why doesn't the battery monitor measure the rate of the power we have coming in from the solar panels at the same fast pace that it measures all the power draining from our battery bank?

Why would anyone have a fit about a battery bank, you might wonder? Because that's where all the power for our boat comes from. That's what runs our fridge, powers our lights and gives juice to the computer I'm typing on. Without it, we would need to drastically alter our way of life. Not impossible, for sure, but it would mean WAY less cheese.

Nothing Vlad said to me was making it any clearer. He tried drawing pictures. He tried detailed explanations. And then he tried turning off the power to the entire boat. That's when he noticed that even with everything turned off we were still drawing three amps, a constant three amps going to nowhere all the time. To solve the mystery, he began unhooking various suspect electrical connections like the inverter and the stereo. Nada. Then, he opened up the engine compartment, put his hand on the alternator and found the source of our energy problem.

Evidently, the alternator had a short in it and was sucking power all the time. We have taken it to get repaired, which means we're stuck in Panama City until that little job is completed, but on the bright side at least it happened in a place where we could actually get it fixed. And our cheese supply is safe for another day.