I just purchased an XB-600. I really like it. I have two questions.
1. I did the "shunt" mod and noticed only moderate improvement (and I wonder if that is only in my head). However, my "factory" performance seemed better than other's listed in various posts. When I did the mod, I noticed that there was a large blob of solder already between the two shunts (on one end of each) on top of the controller board. I did not see that in any of the pictures on this site. Is it possible they are shipping XB-600's with a partial "shunt" mod done with this blob of solder?
2. Experimenting with the bike, both with the back wheel off the ground and with riding the bike downhill, the controller seems to limit not only by amps, but by RPM of the rear wheel as well. If this is the case, how does going to 48v increase the speed of the bike? (not that I am doubting it does).
Thanks in advance.
I meant going to 60v for 48v
--things that are different are not the same. LM.
1. It is possible, even likely given your observation about the solder blobs that the factory is already boosting the current limit somewhat.
2. I had the same wonders about these motors, but it seems they are really DC motors that are driven by pulses, and their RPM is limited by the voltage being applied. They are rated with a RPM/Volt specification, so to go faster, you need more voltage. I have mine running at 60 volts, and it goes about 27 mph (real speed), up from about 20 mph before the 60 volt mod.
just my thoughts,
Tom
It increases your motor wattage. 48v times about 12a stock current(without shunt mod) would give you 576 watts (600 watt motor rating). Increasing voltage to 60 volts without shunt mod would give you 60 times 12a or 720 watts. Mod the shunt which results in current draws up to 50 amps and you get 60 times 50 or 3000 watts peak power. The average hill will make your scoot draw 25amps so 60 times 25 would mean 1500 watts. Now do you see the difference? :) Hope this helps
-Warren
Keep the rubber side down and the shiny side up.