Razor E300 Electric Scooter Speed Controller Upgrade
I recently bought an E300 electric scooter off eBay for use as a Pit Bike. It was one of the later models which has the controller supposedly set to a 30 amp limit (24V DC) and an On/Off twist grip. The method of operation is that you twist the grip to run the motor and when (or if) you get to the speed you want you simply release the twist and the motor is switched off and a freewheel sprocket allows you to coast until you turn the motor back on. It is supposed to provide a better control feel but the speed control pretty is poor in my opinion. The current limit seems more like 20A and does not give much acceleration so I boosted the controller up to 30A and it still was not good and the power On/Off action makes low speed control difficult and quite clonky with the freewheel.
To keep the cost down I decided to see if I could source a better speed controller using voltage control and a proper twist grip throttle but keep the existing 280W motor and SLA battery configuration.. Having looked around I found PetrolScooter in the UK sold various spares for typical Chinese electric scooters including a range of relatively low cost speed controllers, motors and twist grip throttles.
I decided to go for a 24V 500W controller and a nice twist grip throttle with the aim of possibly upgrading the motor at a later date. Although PetrolScooter are relatively local the delivery is free so I dropped them £24.99 and received my controller and twist grip within 48 hours.
The conversion is quite easy with some relatively simple wiring and connector changes. The new controller is slightly bigger and will not fit between the battery and plastic tray as the existing controller did. However, by bending the terminals upwards on the On/Off Switch and Circuit Breaker the controller can be rotated by about 90 degrees and will just fit snugly. The new controller actually ran the motor backwards but this is a simple change of terminals in the motor connector. The other connectors can be adapted by changing the pins into the different connector housings or by cutting the old connector connector and soldering to the new controller.
The new controller seems to have a current limit of 30A but the voltage control makes it much easier to set a motor speed and in my opinion the scooter is much better with the voltage control. My next change will be to add an LED battery meter and possibly raise the current limit to about 40A.
Future mods are possibly a motor power upgrade and LiPo batteries. Ideally I would like to go brush-less but will save that for a rainy day perhaps.
To keep the cost down I decided to see if I could source a better speed controller using voltage control and a proper twist grip throttle but keep the existing 280W motor and SLA battery configuration.. Having looked around I found PetrolScooter in the UK sold various spares for typical Chinese electric scooters including a range of relatively low cost speed controllers, motors and twist grip throttles.
I decided to go for a 24V 500W controller and a nice twist grip throttle with the aim of possibly upgrading the motor at a later date. Although PetrolScooter are relatively local the delivery is free so I dropped them £24.99 and received my controller and twist grip within 48 hours.
The conversion is quite easy with some relatively simple wiring and connector changes. The new controller is slightly bigger and will not fit between the battery and plastic tray as the existing controller did. However, by bending the terminals upwards on the On/Off Switch and Circuit Breaker the controller can be rotated by about 90 degrees and will just fit snugly. The new controller actually ran the motor backwards but this is a simple change of terminals in the motor connector. The other connectors can be adapted by changing the pins into the different connector housings or by cutting the old connector connector and soldering to the new controller.
The new controller seems to have a current limit of 30A but the voltage control makes it much easier to set a motor speed and in my opinion the scooter is much better with the voltage control. My next change will be to add an LED battery meter and possibly raise the current limit to about 40A.
Future mods are possibly a motor power upgrade and LiPo batteries. Ideally I would like to go brush-less but will save that for a rainy day perhaps.
The picture above shows the terminals of the switch and breaker bent upwards to provide more room for the larger controller
With the controller in place, note it is not fastened down but the connectors and wiring do a pretty goo job of holding it down
View of the twist grip (note that the twist grip comes as a matching pair for £10)