Voltage Leak - 2006 Nautique 226 LE

[jpwhit]

This is the kind of thing I was suggesting, just because it's really easy to wire up and cheap. I forgot that it's really hard to find incandescent (non-led) light bulb anymore. This is a 25w so it should draw about 2 amps.

bulb

https://www.amazon.com/Satco-S5010-M...s%2C129&sr=8-6

base with switch. Wires attach with screw terminals

https://www.amazon.com/Leviton-8827-...50&sr=8-7&th=1

What TechBeer is suggesting of using power resistors is good too, and what I actually use. But it's a little more work to construct imo.

I also typically use a power meter for this kind of thing instead of a normal meter. It tracks volts, amps, cumulative AH, and watts and it also stores min and max values. It's also rated for very high currents. They are common for electric radio control stuff which is where I became familiar with them.

https://www.amazon.com/HTRC-Precisio...17&sr=8-6&th=1

[TechBeer]

I agree that jpwhit approach is more straightforward (and safer). I don't know that much about lead acid batteries though. The bulb will likely continue to illuminate well below 10V so it seems like it would be difficult to assess the actual AH rating. At what point is the battery discharged to the point that it won't start the boat anymore? That seems like the critical parameter. From a quick search it seems like 10.5V might be the universal "end point" for a AH test (?). Which I think is what jpwhit said in the first place: Fully charge the battery and run it down to 10.5VDC.

[windsurfnut]

I chased a similar issue a while back, on my 2002 SN196, which was configured just like yours, but without the rear electrical box.
My starting was intermittent. Some days no issue, some days it would be completely dead. I'd put my smart charger on the battery and it would come up charged right away or fairly quickly. I discovered a couple of things along the way, which I'll list below, and ultimately what the cause/solution was:
1. Connections on battery need to be TIGHT for consistent starting. Loose connections, or ones that become loose would become a problem.
2. The BILGE/ON/OFF switch - First, some previous owner (or factory) had messed with the wiring on the switch so that the bilge came on whenever the ON was selected, and therefore was OFF when on BILGE or OFF. I corrected that, but also noted that the tiny switch could be prone to corrosion, wire damage, or short circuiting.
3. BATTERY - Despite my absolute believe that the OPTIMA battery was good, and that the "smart" charger was smart enough to tell me it was a bad battery, this was the root cause of my intermittent start issues. New battery, tight terminals.. never again did I have any issues