gt40 jump start after easy start at first of the year. volts 15 when running.

[brettmcox]

I took my boat out this evening in the voltage meter read 15. that was after I had to jump start it on an auxiliary battery that was in the boat however that battery is not hooked up to anything at this time. I drove the boat around for an hour water skiing with kids and restarted maybe 5 or 6 times. I am wondering if my alternator is going bad or if the starter battery should be replaced.

[brettmcox]

I just got off the phone with nautique parts and they told me that it most likely a bad battery since I do not know the current age. They told me that running no Accessories and the Dash reading 15 volts is fine. When I would turn items on, the volts would drop some (blower (or 1 item) down to 14.5ish, radio (or 2 item) 13.9ish).
I will be taking my jump box and if I have an issue I will just replace the battery with a new one after this weekend.

I will also Hard Wire a switch from the “Just Start” Battery so that i do not have use a jumper cable.

Any have different input?

[DW SD]

do you have a digital volt meter? Harbor freight has a cheapie for less than $10. Amazon has decent ones for cheap or you could spring for a few hundred for a good Fluke.

Anyhow, my dash gauge reads a few (+2) volts too high. I verified with my Fluke. It reads 16V. The proper charging voltage should range between 13.8V and 14.5V, perhaps 14.8V depending upon the batteries' charge state.

You can use the same tool to measure your battery. Measure at least 4 hours after shut-off. You can pull down charts from the internet that will translate state of charge. 12.65 to 12.7V is 100% at about 70F and after sitting for 1/2 a day.

[brettmcox]

I did not have one with me. I will check that on my next trip. Before buying anything. ****, my amp has one on it now that I read this post....

[brettmcox]

**** was he ll .... not any other 4 letter words..