Last summer, starting my generator was problematic, until I removed, cleaned and re-installed the battery end of the connections. I greased them after cleaning and sanding. Problem solved.
Recently, within the last month, I have had several tough starts on my starboard engine. The starter would engage, turn the engine one rev or less, then disengage and spin just the starter. After several tries the engine would start.
I checked the connections. Those are the same connections I had cleaned, sanded and greased last summer. All were good. I checked at the starter (+) and the block (-). Those were clean and tight.
The Port engine starts within 1 revolution. Both + and - cables to the port engine come only from the starboard engine, so I was thinking the connections are not the problem.
Voltage on the start battery was the same as on the house batteries, 13.4v with the charger turned off.
I suspected that a weak start battery should have as much trouble with the port engine as with starboard.
After some head scratching and discussions with some more electrically charged than me, I decided I would replace the start battery. This battery is younger than any I have replaced before on this boat, at only 6 years. I log those sort of things, so know that age for sure.
The new battery, going in, was only reading 12.7v and needed some water in all 6 cells. I tried it right away, and it was able to start the starboard engine on the second try. On the first try the starter engaged and spun the engine maybe one revolution, then disengaged. That was just like before.
I filled the cells with distilled water and left it on the charger for 2 days. Today, I turned the key and it started on the first revolution, just like the port engine.
Conclusions:
Measuring voltage of a dying battery needs disconnection and leaving for a while, or it will be a total waste of time.
Some engines need more oomph than others, even identical engines.
Some batteries last longer than others.
Recently, within the last month, I have had several tough starts on my starboard engine. The starter would engage, turn the engine one rev or less, then disengage and spin just the starter. After several tries the engine would start.
I checked the connections. Those are the same connections I had cleaned, sanded and greased last summer. All were good. I checked at the starter (+) and the block (-). Those were clean and tight.
The Port engine starts within 1 revolution. Both + and - cables to the port engine come only from the starboard engine, so I was thinking the connections are not the problem.
Voltage on the start battery was the same as on the house batteries, 13.4v with the charger turned off.
I suspected that a weak start battery should have as much trouble with the port engine as with starboard.
After some head scratching and discussions with some more electrically charged than me, I decided I would replace the start battery. This battery is younger than any I have replaced before on this boat, at only 6 years. I log those sort of things, so know that age for sure.
The new battery, going in, was only reading 12.7v and needed some water in all 6 cells. I tried it right away, and it was able to start the starboard engine on the second try. On the first try the starter engaged and spun the engine maybe one revolution, then disengaged. That was just like before.
I filled the cells with distilled water and left it on the charger for 2 days. Today, I turned the key and it started on the first revolution, just like the port engine.
Conclusions:
Measuring voltage of a dying battery needs disconnection and leaving for a while, or it will be a total waste of time.
Some engines need more oomph than others, even identical engines.
Some batteries last longer than others.