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Please help me to upgrade a Razor E300S to a 36 Volt 500 Watt rig.

Has anyone upgraded a Razor e300s to a 36 volt/500 Watt system? 

I would like to do this in order to get more power, speed and ride time. Would you please help me put together a complete scooter kit which is based off of a 36 volt 500 watt motor? I will customize everything to fit on the frame that I am using (Razor e300s) or weld a new one, but I am very unsure of how to match all these components. I am starting from scratch and need everything.  

Although my expectations may be false, I am aiming for a speed around 25mph or better. I don't know if that is possible. The rear sprocket, wheels, everything is stock (Razor e300s). If I would need to change the sprockets for better performance, please advise. I also need it to be able to go up and down some hills. Nothing that steep or long, but some hills. The weight being transported is 155 plus the weight of the rig. 

A 500 Watt motor could only power the scooter to around 18 miles per hour on flat ground. For a 25 MPH top speed and the ability to climb hills a 1000 Watt motor would be needed. Here is a gear ratio and top speed calculation made using our MOT-361000B 36 Volt 1000 Watt motor along with a SPR-813 13 tooth motor sprocket and SPR-844 44 tooth wheel sprocket:


For a 36 Volt 1000 Watt motor the minimum recommended battery size is 15Ah (3 quantity of 12V 15Ah batteries).

We sell a 36 Volt 1000 Watt kit for the Razor E300 electric scooter which is our item number KIT-E300-1000B. Here is the link to it:

We can modify this kit or make an entirely new kit for your project depending on the parts that you want the kit to have.

Thanks! This kit looks great. Two question. 

1.Would this setup allow the scooter to go at multiple gradual speeds? The more the throttle twists the faster one goes? This is what I am looking for. Or is it only one of a couple settings, like low and high and the throttle clicks into these settings? 

2. How can I anticipate the driving time? What can I do to this kit to increase the drive time?



KIT-E300-1000B, along with all of our other kits, provides infinitely variable speed control. It will provide infinite multiple gradual speeds, just like the throttle on a gas powered vehicle does.

The driving time depends on the Ah rating of the battery pack, speed that the scooter is driven at, and riding conditions such as terrain and vehicle weight.

Drive time can be increased by installing batteries with a higher Ah rating. The three 12 Volt 15Ah batteries that are included with KIT-E300-1000B are estimated to provide a 40 minute ride time on flat ground at full throttle. The ride time would be less on hilly or mountainous terrain. The ride time could be increased by not running the motor at full throttle all of the time.

If the kit had three 12 Volt 22Ah batteries the estimated ride time on flat ground at full throttle would be 60 minutes.

We have an online ride time calculator that can be used to estimate ride time with different motors, batteries, and terrain. It is located on this page:

If you would like for the kit to have larger batteries then we can make a variation of it with different size batteries.

Please let us know if you have any questions.

Thanks ESP Support! 

Yes please. I would like to go with the batteries that provide an hour or so of ride time. The 12 Volt 22Ah ones that you suggested above.

 Would you please swap the three 12 Volt 15Ah batteries out for the Three 12 Volt 22 Ah batteries that you suggested to get a longer ride time. 

Could you also include a different size sprocket as well as the one that you already included in the kit. This is for me to experiment with. The additional sprocket would be for me to use to make the scooter go faster. I imagine at the cost of torque? 

Then, if this is everything I need, I think I'm set. Yes? 

Hello ESP Support,

Would it be possible for you to modify the kit that you originally suggested based on my previous email? The change is to the batteries and the addition of an experimental sprocket. 


Hi Josh, yes we can do that. The 13 tooth motor sprocket is the largest size made for that motor so a smaller wheel sprocket would be needed to increase the top speed. Yesterday we just added to our site a 36 tooth and 38 tooth sprocket for 8mm chain that will fit the E300 scooter. Here are the gear ratio and top speed calculations for these sprockets.


On flat ground 1000 Watt motor is usually only capable of speeds up to around 25 MPH due to the amount of air resistance (drag) that the scooter encounters at that speed. However, if you would like to experiment with higher gear ratios then there is nothing wrong with that.

If you would like one of these sprockets included with the kit then please let us know.

Thanks! I'm inclined to go for the 36 tooth please. (You folks are a huge help, and I learn a lot from your site too. It's great!) 



Thanks, it is great to hear that you are finding our site to be educational. We try to provide all of the calculators and information to take the guesswork out of modifying and upgrading electric scooters so the right parts can be purchased the first time.

I went ahead and built the kit for your project with a 22Ah battery pack and both 36 tooth and 44 tooth wheel sprockets. It is our item number KIT-E300-1000-20.

Here is the link to it:

Please have a good look at the kit and if you see any changes that you would like made to it then please let us know.

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