What's inside! .. ?: Razor E300 Scooter

[eccerr0r]

Re: What's inside! .. ?: Razor E300 Scooter

While this doesn't handle the lift and go theft, I wonder if faking a dead battery is sufficient as a deterrence. Say it has a bluetooth or nfc module and looks for your phone. If not present, drive at 1mi/hr and conk out in 10 feet.

Well this was an old fashioned car theft deterrent where one could let the engine start and only run for 5 seconds and stall... making a thief's life miserable, hopefully abandoning the car and looking for an easier target to move...

[Curious.George]

Re: What's inside! .. ?: Razor E300 Scooter

Seems speed control is nonexistent or at least not normally accessible. Might have to hack in something to allow easy speed control. I suspect that using this thing at 5mi/hr is probably not very practical, and people would rather just it go up to the maximum speed of 15mi/hr.

Speed control is only obvious for "lightweight" riders. Motor torque drops with speed so heavier riders effectively only have one choice: full throttle (cuz the motor is undersized).

I've rescued and refurbished 6 of them. Found homes for 4, so far (two more in the garage waiting for parts). As they are most useful for lighter/younger kids, I've found parents aren't keen on having their kids able to run "flat out" (as the kids lack the skills to evaluate their risks in doing so). So, I modify the scooters to set an artificial upper limit on their speed -- a simple hack.

[Sadly, it's not practical to harvest parts from smaller scooters as they, too, are sized to JUST accommodate their intended riders. So, I just let the smaller ones go directly to "scrap". Unfortunate, for me, as providing fresh batteries, labor/knowhow AND having to purchase replacement parts out of my own pocket tends to disincentivize me from refurbishing every scooter that comes along (if I could salvage parts from the smaller scooters then I wouldn't have that last expense!)]

Wonder if it's worth to mod for another battery chemistry to do away with SLA, and perhaps with those it might be worth to figure out how to temporarily lock the chain to the tire so that some regenerative braking solution could be made.

I also wonder if regenerative braking is more valuable for heavier people. For me with the scooter's limit of 220lbs, I could carry a few extra battery packs without issue...

Don't bother. If you want to make a scooter for "heavier people", then start from scratch. You'll find that the frame, tires and motor aren't really appropriate for an "adult".

Next problem is that there's no theft prevention for these things. Nevermind one could just lift it up and dump it in a car, one could just joy ride it away as long as the battery pack has charge...

As they are small and lightweight enough, there's no real reason you'd need to "leave it" unattended. Just carry it into the store (or wherever) with you.

My electric wheelchairs are similarly "unprotected". Yeah, I can shut down the system ("lock it") but anyone with any experience would know how to UNLOCK it! The thinking being that you're likely IN the chair if you need a $40K chair and not likely to leave it sitting, unoccupied, outside the store! :-/

[eccerr0r]

Re: What's inside! .. ?: Razor E300 Scooter

Ouch batteries are really shot. As of right now, each battery pack OCV is ~11.8V and DC ESR is almost 1Ω estimated. Seems the expectation that the ESR should not be above 300mΩ or so.

Seems speed control is nonexistent or at least not normally accessible. Might have to hack in something to allow easy speed control. I suspect that using this thing at 5mi/hr is probably not very practical, and people would rather just it go up to the maximum speed of 15mi/hr.

Wonder if it's worth to mod for another battery chemistry to do away with SLA, and perhaps with those it might be worth to figure out how to temporarily lock the chain to the tire so that some regenerative braking solution could be made.

I also wonder if regenerative braking is more valuable for heavier people. For me with the scooter's limit of 220lbs, I could carry a few extra battery packs without issue...

Next problem is that there's no theft prevention for these things. Nevermind one could just lift it up and dump it in a car, one could just joy ride it away as long as the battery pack has charge...

Hmm... The practicality of these things...


Hooray found a picture of the guts so I don't have to tear it apart!

https://hackaday.io/project/9941-the...-e300-overvolt

[Curious.George]

Re: What's inside! .. ?: Razor E300 Scooter

Seems like this cheap crap scooter has a 1-speed on/off "throttle" - now, I don't get what's with the heatsink, now I'm *really* wondering what's in the box... There's definitely a relay but relays don't dissipate much heat...

It's a PWM controller. The throttle controls speed by altering the duty cycle. As the MOSFETs are eitehr full on or full off, the amount of power dissipated there is "manageable".

7Ah * 24V = 168Wh... hmm... store energy...

60AHr * 24V = 1440WHr in my electric wheelchairs (many have even bigger power packs... and that's before changing battery chemistries!)

[eccerr0r]

Re: What's inside! .. ?: Razor E300 Scooter

Wow. I see spinning. Yep the batteries were completely gone, though I somehow got enough charge into them to finally get the motor to spin. About 200mA is charging through now, though at 200mA and 7Ah is a long time to charge.

Seems like this cheap crap scooter has a 1-speed on/off "throttle" - now, I don't get what's with the heatsink, now I'm *really* wondering what's in the box... There's definitely a relay but relays don't dissipate much heat...

7Ah * 24V = 168Wh... hmm... store energy...

[eccerr0r]

Well, I was working on an Razor E300 scooter and first off the batteries were dead. Well duh, that would explain why it won't work. However what was interesting is that I noticed a heatsink on the control module... I wonder if I should open it and would anyone notice...

Anyway I did see videos about the E100 scooter which has two relays. From what I gather, it seems that one relay is to turn on the motor, but the other one I'm not sure about. Whether this translates to the E300 I don't know. The heatsink seems to indicate it has transistors, alas it still has at least one relay as it clicks.

I was also wondering if it were possible to add regenerative braking for riding it in hilly places, but that got quickly dashed by the ratcheting mechanism of the rear wheel. Oh well. The newer direct drive units seem to be the way to go, and not this chain drive ⅓HP motor...

---

I thought I found a reason to open the box but turned out to be due to the charger circuit telling the scooter to not go when it's plugged in. Drat. Thought I was getting somewhere when I got the batteries to read out 13.x volts but nope. So with the charger disabled, it ... well ... tries to power the motor, alas unsuccessfully. Battery voltages plunges like a rock, so we know the batteries are still sick, though at least it's still drawing some current while charging...