Charge rate for Nissan 25/30

[Wee Hooker]

Being that I do some remote boat camping (where Trolling Motor battery charging is the limiting factor), I contacted Tohatsu to find out what the output for the (16amp) alternator was at less than WOT RPM's. It took them a few days and a call to Japan to find out but they followed through and sent me a graph of output vs RPM. I can tell you that I was surprised by what I saw.
Bottom line is that the alternator output was beyond 50% capacity (9amp) at 1000 RPM and near 85% output (12.5 amps) at 2000RPM. The curve levels out at somewhere around 3000RPM/13-15 amps (depending on A or B model). Nice to know I can putt around and still get good charging benefits out of this motor! I can't say that this is typical of all Tohatsu/Nissan alternators/outboards but figured I'd share the data point since charge rate is a frequent topic around here.
hth

 

[pvanv]

Re: Charge rate for Nissan 25/30

Good point. This is typical of all the Tohatsu/Nissan 4-strokes. Even the [smaller] 6-amp system on the 8/9.8 comes up to a pretty good output at relatively low RPM, actually charging somewhat at just above the 800 RPM idle. Since these charging systems are also regulated, there's no fear of overcharging (and boiling a flooded battery), either.