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Modifying razor e300

So I decided to modify my razor e300. I purchased a variable speed kit with controller, 2 12 volt 10amp batteries and. 350w motor. Was looking for thoughts, will all of these work. They are all listed as parts for the e300. I was thinking this was the safest way to upgrade. I welcome all expert opinions Thanks

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The 12 Volt 10Ah batteries can be installed in the upright position by raising the original footplate off of the frame with spacers and longer bolts, or by making a custom footplate with a hole cut in it for the batteries to stick out of.

The 350 Watt motor should fit, however, its sprocket is a little further out from the mounting plate than the 250 Watt motors is so the mounting holes may need to be elongated to get the sprockets properly aligned.

Will this mod also work on the E300S, the model withOUT the chain tensioner?  Instead of elongating the holes where the motor mounts, would it instead be a good idea to just space out the rear sprocket a similar amount as the 350 front is (vs. the 250 watt front)?  Also, I wonder if on a very low "geared" E300S (9-89 sprockets), if this 40% boost in power would even be noticeable.  On flat paved ground, even with the 250 watt motor, it seems to "zing" up to speed rather quickly and then just "sit" there at about 10 MPH or slightly under.  I can actually run alongside the scooter when it under motor power as the sprockets greatly limit the top speed (on flat ground).  Perhaps the stronger motor would be fun for extra power across grass and also to allow me to use my booster battery pack which is basically 2 more 12V 7Ah batteries in my backpack, with a multiconductor wire to interface to a quick disconnect on the main battery bank.  That is mainly only used for long trips (more than about 6 or 7 miles).  It will also help with the stronger motor since situations such as going across grass and/or going up hills with the 350W motor will drain the batteries quicker I suspect.  Sounds like a fun project.

Also, I wish they would use different model numbers for the 250W and 350W motors for easier identification.  Sometimes the stickers get scraped off from bottoming out the scooter like over speed bumps and if all you can see if MY1016, that wont tell me what motor it actually is (the 250W or 350W).  Also, I was wondering what might happen if I overvolt an E300S to 30V (by adding a 6V battery in series).  Will the controller take it or shut down due to overvoltage?  I have a way to charge that setup by charging the 24V and 6V subbanks separately.  I wonder if that overvolt of 25% would make the 250W motor perform more like a 350W motor, thus saving the expense of having to swap motors.  It seems reasonable that they should be close.  Anyone ever try this or just overvolting an E300S 250W motor in general?

We don't see why not. We have not tried spacing the sprocket from the freewheel before but it sounds like a likely candidate. With the same gearing, we would not expect extra speed and only extra torque with a more powerful motor that has around the same shaft speed. Overvolting will increase speed and power. The controller or motor should not shut down from overvolting, however, there is a chance of them burning out from it. 6 Volts is a pretty mild overvolting though. We are not sure what the performance increase with a 6 Volt overvolting would be. 

One "easy" way to space the rear sprocket to match the front sprocket sticking out more on the 350W motor, would be to take a small sprocket and put that directly on the freewheel and then piggyback a larger sprocket on that, and use longer that stock bolts if needed to secure them.  My friend and I will test the 30V E300S as soon as tonight and report back our findings.  I have a special laboratory power supply unit (lab PSU for short) that can charge the 6V battery separately, at any rate I choose from 1mA to 3A in 1mA increments (3000 possible different constant current charge rates).  My idea is to mount the 6V battery external to the battery bay and wire it in such a way that the extra 6 volts can be added easily at will, but if not needed, the 2 wires where the 6V battery gets inserted can easily be coupled to go back to 24V (that feature will be needed anyway to charge the 24V pair).  My E300S is "geared" down very low, so if this 25% overvolt gives me even a little overspeed of the motor, that will give me the "best of both worlds".  That is, more torque from the overvolt, and the 3000+ RPM (hopefully) cancelling out some of the lost top speed.  I would be happy with the power of a 350W motor (using an overvolted 250W motor), and a top speed of about 10 MPH (I am running 9-89 sprockets).  If I want lots of speed, I can just ride my 75,000 watt equivalent gasoline motorcycle... but when it comes to scooters, I like riding on paths, up hills, across grass... and that requires a low gear and some power (think about what happens when you ride a bicycle uphill and/or across grass).  Check back soon for the results of this experiment.  Also note that they sell 6V 10Ah batteries so those would be a good match for 12V batteries from 7Ah to 10Ah.  They don't have to be exact in rated capacity.  I suspect the mileage between charges will be about the same, since the higher top speed and more torque will draw more power and thus cancel out any possible range increase.

I tried adding a 6V battery on the E300S and it worked intermittently, meaning the "throttle" (actually an on-off switch) acted up a lot with the 30V setup.  However, the power was better and so was the top speed.  After putting it back to 24V, the "throttle" returned to normal operation.  So my conclusion is 6V extra is too much.  I will next try adding only 4V by buying a 4V 9 Ah battery.  I suspect that will work.  To charge it, I will break the 28V connection and put it back to 24V and 4V and charge those separately.  I haven't yet confirmed the 28V setup works reliably but after I try it (will take about a week to really test it well), I will report back.  My setup is the E300S (the model withOUT the chain tensioner), with 9 and 89 tooth sprockets.

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