Thanks for your help guys.
I would run into endless-sphere once or twice but didn’t really look into it that much.
Thankfully the Robotics Club has a lot of spare parts, so I may swap the motor out for a brushless one and possibly build a li-ion pack if the SLA is dead.
Typical failures is a blown fet in the controller which may shut the controller down. You can always drive the motor direct from the battery. I’ve also has the keyswitch contacts (inline with the power) have problems.
I have 3 identical scooters. One in a basket, one all over my shop, and one still put together. The basket case ended up with a fried winding in the motor. And the my real issue now is getting a couple of good batteries.
It simply comes down to a process of elimination!
Thanks NightSpy, hope I’ll be able to get the scooter up and running and that the problem isn’t too critical.
Have you tried doing that ?
Unlike a gasoline engine, an electrical motor has maximum torque from the start, so by running the motor direct from the battery every time you flick the go switch your highly liable to either be pulling a impressive wheely or ending up on your arse.
plus you either need a relay or a very large switch to handle the current draw
If it is the controller that’s failed,its far easier to buy a new universal controller for around $10 and fit that 
I was thinking trying this on a test stand… not as a fix. Our scooters are 350W motors so a direct connect isn’t that big of a jolt. Free running, my motor is pulling 2 amps at 12V. These are 36V 30A motors.
Not sure you noticed, but that scooter has a real bad case of IIOS (Insufficient Illumination Output Syndrome). You clearly have enough space on the steering column for one or two of these. Beam shot is in Post 10.
I just got the scooter, and everything seems to be just fine except the two SLA batteries. Thanks everyone for the help.
It seems to have been left uncharged for quite a while and will need to have the electrolyte replenished with distilled water.
Are SLA batteries okay to be operated sideways, on their sides?
not if you add water. I tried reviving 4 so far… all for not.
But maybe you can help find a reputable battery supplier that has some robust insides.
So far only Power-Sonic came up somewhat desirable, but the deep cycle ones I found were a 17 week leadtime.
Sorry to hear that, it is indeed quite devastating when something turns out to no avail after some hard work.
Hopefully I can restore the cells, and if not, I could try building a li-ion battery pack with my salvaged laptop cells.
Have you guys seen the “electric unicycles” ? They look cool but totally unsafe. I want one!
Wow, looks like a poor man’s Segway. I’d love to try it out too.
Segway w/o that goofly long handlebar thing
imagine the faceplant if you caught a curb or something that stopped the unicycle but NOT you
Definitely an interesting little getup…
In that case, I am very much looking forward to the battery pack build, particularly your charging solution.
You cannot drive a brushless motor directly, you need to use a controller.
Yes.
Hoping your batteries revive. Those SLA's are notoriously fickle. So connections and fuse look good? If not the batteries (sudden failure indicates not likely a battery issue), the next biggest culprit is a relay.
How many lumens??
Sorry. I could not resist it!
It’ll probably be a pack of 6 cells in series, I haven’t decided how many to have in parallel. Maybe as many as I can fit? Charging will be done via a balancing hobby charger. Getting all the cells to match up in capacity will require some fiddling around though.
I think the cheap scooters (<$300) have brushed motors. I read a great insructable yesterday about using RC parts (BLDC motors and ESC’s) for an electric scooter, that that might be my new project. http://www.instructables.com/id/The-New-and-Improved-Brushless-Electric-Scooter-Po/?ALLSTEPS
Yup, everything looks good. I hooked up a 25V voltage supply in place of the dead battery and everything was working fine. Hope to get it up and running soon.
Not enough… yet.
Typical capacity for a scooter is around 300wh. This gives you a reliable 5 miles or so. Less if you’re climbing hills (read: slight incline for a duration).
I would think the newer 26650 or 32850 would be desired for power density. Of course, LiPoFe is probably an easier solution from a robust standpoint.
However, SLA’s are still cheap and easy to maintain… if you remember to do so
Yeah the range rated at about 8 miles for the scooter with the Pb battery. I’d go for pre-made 6S lipo RC batteries if they weren’t so prohibitively expensive. Maybe if I apply some funding from the Robotics Club I may be able to afford some upgrades. Meanwhile, I’ll be reading up on batteries!
I'll contribute $5.00 to the "Ryansoh3 is in America Going to College and Needs a Scooter Battery Fund".
PM'ing you for your PP info.