Carlos,
If you're talking about the sailboat conversion kit from Thunderstruck Motors, then it may not meet your expectations. The page on the website is short on specific info, so it is difficult to say exactly what is in the kit, but the limited info that they do supply leads me to believe that one cannot expect it to deliver 8.5kW of power for as little as one hour.
The picture on the website shows what appears to be a Mars ME0907 single stator motor. The manufacturer rates this motor for 80A continuous for up to 72V. That works out to less than 6kW at 72V. For a 48V system, the rating drops to less than 4kW continuous input.
The picture shows a Sevcon Millipak controller which is also rated for a 48VDC max power output of 4kW (from the Sevcon webpage). However the Thunderstruck webpage lists a Sevcon Gen-4 275Amp, programmable, regen controller. The only Sevcon Gen-4 controller that mentions 275A in its ratings is the G4827 controller. This controller is rated for 110A continuous (60 minutes)with a maximum nominal voltage of 48VDC. That works out to be almost 5.3kW.
But a drive system can only be driven as hard as its weakest component. In this case, the ME0907 motor will only take 4kW continuous current at 48V. And these ratings are in ideal conditions. In a boat, you will probably find that one of the components will overheat at somewhat less than maximum ratings unless measures are taken to maximize the cooling for each of the key components.
I know that almost everyone here runs their systems at much less than full power to extend their range, but if one is considering putting one of these systems in a larger sailboat (i.e. 15,000 pounds or 7.5 tons of displacement) then this motor system will be regularly operating at higher loads than most systems discussed here.
Has anyone in this group run their Mars ME0907 at 80A at 48V for one hour in their boat? If so, did you notice if the motor was noticeably hot after that load?
What I'm trying to say is that this system appears to me that it should be rated at 4kW (5.3hp) as described. Even if the kit includes different, more powerful motor, the described controller becomes the system's limitation at 5.3kW (7hp). Installed in the bilge of a sailboat, either configuration might struggle to meet even those power levels for sustained periods.
I believe that an informed decision is a better decision.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "Carlos Silva" <pahuac@...> wrote:
>
> I am about to start my conversion with this kit and therefore would very much appreciate comments on actual experiences and tips.
>
> Thanks,
>
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