Razor Ecosmart project: "The Sting Razor".

Hepgreg

10 µW
Joined
Sep 25, 2022
Messages
6
Hello endless sphere community, new member here. I recently picked up an older Razor Ecosmart scooter, been working on it for a month or so. I've read through a few threads on here already about them, just wanted to set up a place to document my work on this project and get some input on the things im not so knowledgeable about.

So first off, here's my scoot in its current state!
6A2F8267-32B7-4F22-AC33-B46E1AF37CE8.jpeg80E9774C-3AB2-458A-8C97-B1BEB24B7986.jpeg

i started off by removing the basket & adding a sting ray seat & sissy bar. i made some new handlebars, 24" wide with no backsweep. dialed in the headset, wheel hubs, it rides super solid now. replaced the tires with some 16 x 2.3s.

ABC2735E-19DE-4213-ABFB-EED8239F049C.jpeg

Currently running some 12v 15ah batteries. Range is good, speed is not. I put a 55T sprocket on the wheel, definitely gained top speed, but lost acceleration & it puts alot of strain on the stock motor. I will probably swap back to the stock wheel sprocket until i can upgrade my motor & controller. I need to reupholster my seat, thats my next project. Eventually i want to switch to a lithium battery to reduce weight & maximize my range, but i will most likely wait until i trash these SLA batteries before making that switch. Im not very knowledgeable about motors or controllers, so ill be looking for some help about that as well as the right battery setup when i make the switch to lithium.
 
Some pointers below:

Hepgreg said:
Currently running some 12v 15ah batteries. Range is good, speed is not.

For the same battery, range will go down when speed goes up, because air resistance will increase at the higher speed.

With SLA batteries, you'll only get around half their capacity using them the way EVs do; the capacity is rated by a method using only a tiny amount of current, vs the large currents EVs use, and lead-acid's ability to deliver is affected by how much current is being drawn much more than other chemistries.



Just changing the battery (assuming the new is equal in rated capacity and voltage, and is at least equally capable in current-delivery vs voltage sag) could nearly double your range.


Increasing the voltage of the battery will increase your top speed, more or less proportional to the difference in voltage from what it is now. (for instance, if you get 15mph now with 36v, then with 48v you'd probably get about 20mph, assuming the controller and motor can handle the increase in voltage, and also the power required to go the faster speed--they probably can't do it for long though).


I put a 55T sprocket on the wheel, definitely gained top speed, but lost acceleration & it puts alot of strain on the stock motor. I will probably swap back to the stock wheel sprocket until i can upgrade my motor & controller.

The sprocket change is another way to increase speed, but as you found it will proportionally decrease torque at the same time. If you need to stay at the same voltage, then the sprocket change is one way to do that, while changing the battery, motor and controller to one that can handle the proportionally higher current draw required to keep the same torque.




Which battery, motor, and controller to change to will depend on your ultimate goals, and your riding style, terrain, wind, weight of you and anything you carry plus the scooter, etc.

I recommend going to the http://ebikes.ca/tools/simulator.html and reading the whole page, then setting up different systems to see how they behave under your specific riding conditions/etc., to get an idea of how much power, how much current at what voltage, will do what you want to do with the system under those conditions.

It takes a bit to learn what it all means to you, but it's helpful in seeing the relationships between different things, which will help you figure out the general power level you need, and guesstimates for current and voltage.


WHen picking the controller itself, you should think about the features you'd like it to have:

--display? what should it show you? what controls should it have?

--brushed or brushless? (brushed is more efficient, but may need a bigger size and setup to give you the same low-end torque from a stop, as what you have now probably doesn't actually limit current so it'll just do whatever it can physically do until it burns up--brushless won't, it usually has protections against that).

--regen braking? on/off, or variable?

--user-settable/programmable? what type of things would you like to be changeable?

--square or sinewave? (sine is quieter) There's also FOC which is also sinewave, but more complicated and requires specific info about the motor to set it up, unless the controller's autotune/autodetect routines are good.

--sensored or sensorless, or dual-mode? (sensorless/dual works even when hall sensors in motor aren't working..but sensored startup is almost always smoother/easier).

--single-voltage, or wide-range? single-voltage means it only works with the particular voltage battery you choose it for. wide-range means it can work with a variety of different batteries, should you choose a higher voltage later for more speed or simply more Wh, etc, but it can complicate LVC (low voltage cutoff) protection of the system for empty battery, if it is autodetecting vs manually setting this in the controller. (the BMS of a battery will have an LVC too, but you don't wnat to depend on that becuase it is a safety shutoff that works when battery is *really* dead, and it's much harder on the battery to do this).

--current limit? how much current do you need it to supply to the motor?


Battery questions:
--chemistry? (generally this is between LiFePO4 and "Li-Ion" (which comprises a bunch of chemistries that are not usually specified by the sellers, but are not typically that important)). Biggest difference is it's easier to find a small pack that can output higher current in "Li-Ion" than LFP.

--current delivery? how much current does it need to supply? (this is determined by what the controller has to pull from it, worst-case--get a battery that can do say 20-50% more than is needed, so as it ages it still works fine.

--capacity? how many Ah does it need to supply? (how much range do you need) This is determined by how many watts it takes to run the system vs how much time it must last; often defined as Wh/mile or Wh/km; guesstimates can be made for various EVs for how much this will be vs how fast it needs to go vs conditions it's ridden under.


Motor:

--will it fit in the space you have? (will it stick out too far?)

--will the sprocket you have fit on the new one? (if not can you get one the same size to work?)

--what k/V (winding, RPM/volt) do you need to make it spin the right speed to drive your wheel the speed you want, at the battery voltage you're going to use).

--how much power (watts) does it need to do the job you need it to do? Is the cooling it will get in the spot it will go enough for the heat it will generate?

--is it sensored (with standard UVW / 3-phase hall sensors)? Or sensorless?



there are other things to think about but those are a start. :)
 
Wow, thats alot of info! Thanks. I will look it over, and check out that simulator.

I think my end goal is to switch to a 48v setup with a LiFePo4 battery, and a motor with 750-1000 watts. that seems to be the most effective combo for this particular scooter, based on the battery tray size and motor size/mounting plate. Ideally a range of around 20 miles would be perfect, with a speed in the 15-20mph range. Based on what i have read about upping the voltage, this seems attainable for the ecosmart.

With the stock motor/controller/sprocket and the 36v 15ah battery, i get a range of about 14-16 miles, depending on hills. but because of the added weight of the battery, my top speed dropped a few mph from the stock batteries, which kind of bummed me out a little.
 
Hepgreg said:
I think my end goal is to switch to a 48v setup with a LiFePo4 battery,
Keep in mind that generally the LFP batteries are lower capacity/power for the same size/weight. vs other chemistries (but it depends on the form factor of the cells; if they are prismatic or pouch you'll generally have more battery and less airspace in the pack, vs cylindrical cells, but they will need compression to ensure they don't swell, whcih cylindrical's don't). LFP takes more cells in series to do the same voltage (and thus the same Wh) for the same Ah capacity as a "LiPo" pack.

So to really compare this kind of thing, you'd have to directly compare specific batteries you might be considering using.

Ideally a range of around 20 miles would be perfect, with a speed in the 15-20mph range. Based on what i have read about upping the voltage, this seems attainable for the ecosmart.

Fair rule of thumb for around 15-20mph is around half an Ah per mile at 36-48v, (which would be around 25wh/mile-ish) given flat roads and gentle riding conditions, for a bicycle. Probably applies well enough to your scooter too.

The simulator will give you a better idea what numbers really apply to your usage scenario, but you could guesstimate with 25wh/mile, 20 miles range, 20 * 25 = 500wh. With a 48v pack, that's a little more than 10Ah, call it 11.. With a 52v pack, 10Ah is enough (assuming 25wh/mile is correct). These all assume that usage continously thru the whole ride, which is not typical; so you'll probably need less battery, but having more is better for aging, so:

if you can go to 52v (14s LiPo) and 15Ah or more, it would give you more capacity to ensure you still get what you want even under adverse conditions and as the pack ages (and becomes less capable). Higher voltage means that even as the pack is close to empty and voltage has dropped, it will still reach the top speed you want (you'll have to verify the actual voltage needed for whatever motor you use vs gearing vs wheelsize).
 
Any more info on the handlebars? Did you use some existing heavy duty scooter bars and cut them down? I am looking to get some wider bars for my E300 but I haven't seen anyone try to modify existing parts for the electric side of things. I am sure they use the same parts across many models
 
MorbidlyObeseKoala said:
Any more info on the handlebars? Did you use some existing heavy duty scooter bars and cut them down? I am looking to get some wider bars for my E300 but I haven't seen anyone try to modify existing parts for the electric side of things. I am sure they use the same parts across many models

I work for a freestyle push scooter company called TSI Scooters, they are a model we make called TV Bars. They are made from 4130 chromoly, 1-1/4" steertube & 7/8" crossbar. We make them 30" tall, but they fit on any 1-1/8" forktube so I just cut them down to the right height, cut a slit in them so the clamp would compress and theyre good to go :) you can check us out on instagram or facebook, or check our webstore at www.TSIscooters.com
 
Repurposed an old roadkit softcase for under-the-seat storage. Sewed on a few velcro straps for the seatpost & sissy bar, stays in place nicely!

41E9D9BE-6855-4D05-A479-558A19F4DB25.jpeg
 
After looking through the service manual & watching some youtube videos on the braking system, i realized that there was supposed to be a spring that pushes the lever on the drum back out... rummaged around at my work & found one that fit, no more scratchy brakes. :)

51C531D8-1399-4850-A1C5-3EA352F35914.jpeg
 
Hello endless sphere community, new member here. I recently picked up an older Razor Ecosmart scooter, been working on it for a month or so. I've read through a few threads on here already about them, just wanted to set up a place to document my work on this project and get some input on the things im not so knowledgeable about.

So first off, here's my scoot in its current state!
View attachment 323876View attachment 323877

i started off by removing the basket & adding a sting ray seat & sissy bar. i made some new handlebars, 24" wide with no backsweep. dialed in the headset, wheel hubs, it rides super solid now. replaced the tires with some 16 x 2.3s.

View attachment 323878

Currently running some 12v 15ah batteries. Range is good, speed is not. I put a 55T sprocket on the wheel, definitely gained top speed, but lost acceleration & it puts alot of strain on the stock motor. I will probably swap back to the stock wheel sprocket until i can upgrade my motor & controller. I need to reupholster my seat, thats my next project. Eventually i want to switch to a lithium battery to reduce weight & maximize my range, but i will most likely wait until i trash these SLA batteries before making that switch. Im not very knowledgeable about motors or controllers, so ill be looking for some help about that as well as the right battery setup when i make the switch to lithium.
Im looking to upgrade the tires on my eco smart sup scooter. What tires are you running?
 
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