I am new to the forum as well as electric scooter ownership. I just acquired two new (to us) electric scooters; the eZip 1000 and the eZip 900. So far so good. We like them. They are fun but (as you can probably guess) we wouldn't mind more speed and range out of them. I've done a fair bit of research and I think I've got my bearings but I still would like to confirm on some of my understandings. Answers to these questions would be most appreciated.
- Ways to Add Speed: There are two common ways to increase speed. Either by altering the sprockets or by increasing the voltage, correct? Are there any other simple methods?
- Increased Voltage: By increasing voltage by adding an additional battery, I do NOT necessarily gain more range because even though I add another battery the draw of power will be higher and I will still be at the range of the aH of the battery, correct? I have read that, for example, increasing a 24v scooter to 36v will reduce my range by 33%. Is that correct?
- Changing Sprockets: It is my understanding that changing my motor or wheel (or both) sprocket can increase overall top end speed but it would be at the expense of hill-climb ability and torque. Is that correct? Would acceleration (even on flats) be also diminished?
- Range: It would appear that the simplest way to add range is to replace the existing size batteries for those of a larger capacity. So if it comes stock with three 7ah batteries, going to three 10ah batteries would increase range by 43% (more or less). Is that correct?
- Increased Range & Speed: This is always the question it seems but it appears that to truly increase range and speed you must increase the voltage of your scooter AND add batteries that are of considerably higher amp:hour size. This seems to be where Lipo/Lion batteries enter the conversation and blow out the budget. Am I tracking correctly on that?
Sorry for the long winded first post but I wanted to confirm my understandings before I get into specific questions. Thanks.
Thank you for joining our forum and for your very well formatted list of questions.
Regarding ways to add speed: Changing the sprockets for a top speed that is within reason for the power of the motor will work. Increasing the Voltage will also work, however, could possibly overheat and burn out the motor. For motors in the 900-1000 Watt range, a top speed gearing of 25 MPH or less is suitable.
Regarding increased Voltage: Adding an additional battery usually does not result in increased range because the power consumption of the motor will increase along with the increase in Voltage. I am not sure if adding an additional battery will result in a decrease in range or not though. That probably depends a lot on the gearing, how fast the scooter is driven, the terrain it is driven on, etc. Different scooters, riders, and riding conditions will affect the range of different size battery packs so there is no definite black and white answer to this question.
Regarding changing sprockets: A sprocket change that increases the gear ratio will lower the torque at the rear wheel which will lower rate of acceleration and hill climbing ability. A higher gear ratio will diminish the rate of acceleration on flat ground.
Regarding range: Yes you are correct. Increasing the Amp hour rating of the battery pack will increase the range more or less proportionally to the amount of increase in Amp hour rating of the battery pack.
Regarding increased range and speed: We do not recommend increasing the Voltage to increase speed, however, it can be done at your own risk. Many of our customers have shared success stories of overvolting motors, while others have shared stories of their motor overheating and burning out shortly after overvolting them. The safest way to add more speed is by changing the sprockets for a top speed that the motor can handle, or if the motor can not handle the top speed that you want the scooter to have then upgrading to a more powerful motor and controller along with changing the sprockets for an increased gear ratio.
Thank you for the detailed response and for confirming or adding to some of my assumptions.
I now have a more specific question. It seems to me that my the top speed of around 15 mph on my eZip 1000 feels more like a governance than an electrical/mechanical limitation. Like, it feels like there's power there but it just tops out so fast.
I have read about a YK43b controller. It seems like this controller can leverage the stock 36v of this bike but push it to the motor in a manner that derives more speed. I have no facts or figures on that though, only things I've read on forums.
Also, it appears that my 1000 is a direct drive scooter so it is my understanding that a sprocket change is sadly not an option available to me. Is that true?
And finally, I would like to utilize a free-wheeling hub for better coasting. Is that possible on a direct drive scooter?
And if you have time, I'd love to know what recommendations there may be for a free-wheeling hub and sprocket changes for my eZip 900 as well. That scooter appears to be a fairly limited run but rather closely approximates the eZip 750.
The top speed is limited by the gear ratio to 15 MPH. The 900 and 1000 Watt motors are capable of faster top speeds with different gearing, however, they are not electronically or mechanically governed and they run at their maximum RPM for the Voltage they are run on so the only way to obtain a faster speed is by increasing the gear ratio or overvolting the motor. We have received many reports from our customers of the 1000 Watt eZip (Currie) motors being overvolted to 48 Volts taking it very well and not burning out, however, this is not something that we have tried ourselves.
We are not sure if the YK43B will increase the top speed as this is not something that we have tried before.
We do not know of any different gears that are available for the direct drive Currie scooters or any way to make the drivetrain freewheel.
The eZip 900 and other eZip and IZIP scooters with chain drive powertrains can be converted to have a freewheel by installing an FWM-120 Freewheel along with a #25 Wheel Sprocket that Mounts to a Freewheel.
Installing a freewheel and sprocket may change the alignment of the wheel sprocket to the motor sprocket so spacers such as washers may be needed to bring the new wheel sprocket into alignment with the motor sprocket.
That definitely makes sense and I again appreciate your time in answering my questions.