Wattage on SW900 Display?

jacobc

1 µW
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Jul 22, 2017
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What does the wattage on the SW900 display means? How accurate is it? I've looked through the existing manual on boatstogo (google's #1 link) and youtube videos, but they're both unhelpful.

I have a 48V 1000W kit from eBay hooked up to a 48v 20Ah battery. When using throttle-only mode with the throttle pinned the wattage on the display consistently reads between 200-300W, yet I'm moving at about 50 kph (31 mph). In my mind, there's no way a 200W motor is pushing me at 31 mph unless I'm pedaling like a fiend. Likewise, in PAS mode 5, I'm generally moving about 30 mph with near effortless pedaling, but the display shows 200-300W. Why? Moreover, at this wattage the battery should last 4+ hours - that clearly doesn't happen. I get about 25-30 miles of range - pretty consistent for a 1000W.

The only exception I've seen, and I haven't pinned it down exactly is sometimes in PAS mode 3 or 4, the meter displays 800-1000W. No idea why.

Thanks for any help in understanding this. Just trying to understand my bike better, but googling for over an hour hasn't turned up anything of use.
 
I think those kits/displays are marketed towards 48v and 20 amp controllers (ie, approx. 1000w) so the display only goes to 999 watts. If you're drawing more than 20 amps on a full battery, perhaps you've tripped the watt meter, so 999 + 200 will only show 200 watts. That may also be why while on a lower PAS setting (with lower current?), you're seeing the 800-1000w range.
 
rote said:
I think those kits/displays are marketed towards 48v and 20 amp controllers (ie, approx. 1000w) so the display only goes to 999 watts. If you're drawing more than 20 amps on a full battery, perhaps you've tripped the watt meter, so 999 + 200 will only show 200 watts. That may also be why while on a lower PAS setting (with lower current?), you're seeing the 800-1000w range.
Good explanation. You get a merit award for that.
 
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