Yeah man, a lithium pack is a really good upgrade! If the pings don't have enough punch you could always get some lipo!

Money
 

For the kind of money you are thinking of investing I personally would rather spend my cash on the A123 nanotech cells (Link below). More bang for the buck if you ask me. More power, better configuration choices, lite weight, and you can work with them to have a custom pack made just for your project. I have been considering an A123 custom pack myself for an E-bike project, and now you have me thinking about a scooter. It seems more affordable to find a good used scooter CHEAP and then do this conversion like you are considering. Live and learn I guess. This is why I like reading about things like this on our forum. Thanks for sharing your experiences with us.


http://www.a123systems.com/products-...pouch-cell.htm

Ping batteries are made with prismatic cells. Now are they the same ones as you linked I couldn't tell. The ping batteries also come with a Battery Management System built in and are sold with matching charger. Most people I've seen that wrote about their experience with Ping Batteries is positive. Good product at a reasonable price and very good customer service. There are other options for already made batteries out there, even better quality but for double or triple the price. I can build a battery, I've done it countless times. I just don't want to play with that kind of voltage and amps.

E-Bike projects are great and so are E-Bikes. But for me, I realized that it was just that, a bike. I thought something that is more sturdy like a small motorcycle would be better for me. So I looked into scooters. I really don't regret my choice, it rides really well, it feels solid on the road and people see you a little better. If you're going to put a lot of mileage on a two wheeled electric vehicle, might as well be a scooter or a small motorcycle. There's quite a few that like to convert 250cc motorcycles and they can be found used real cheap. But they do spend months building them and they spend quite a bit of money also. Depending on how well they built it, they might have to tinker on it every weekend to fix things that failed. I don't have the time or energy to do that. I wanted something already made with a warranty and that's what I got and it is serving me very well. In October, I will have reimbursed myself the price I paid for that scooter with what I saved not using or even having a car.

I can understand a little bit why electric vehicles never took off because of many political reasons shall I say. There are a lot of filthy rich companies that would go down real fast if tomorrow, just half of the world's car users would switch to an electric vehicle like a scooter or E-bike. Now that I got used to do things with a scooter instead of a car, I don't miss not having a car. That may change this winter but we'll see, I'm holding my grounds here! BIG OIL COMPANIES CAN KISS MY BUTTery! Maybe I should put that on a T-Shirt.

A123
 

A123 prismatic cells look very similar to Lipo cells in general. The thing I like about A123 batteries is that they can package whatever configuration you want and make it look very much like a small lead acid car battery. The packaging looks very professional and you can work a package with charger and battery management system built into the pack. Yea building packs is not all that hard, but I agree with you about working with voltages that high is kind of dangerous and I would avoid it if possible. Thats just me.

I also agree with you about the construction of a scooter compared to an E-bike, and the scooter would offer a much safer ride for sure. Whether you are seen or not depends on traffic conditions, weather, and what you wear when you ride. I would even go as far as to change the horn and put something with a little more throaty sound. Most car drivers would never even hear a scooter horn. Good luck with your conversion/upgrade and keep us posted.

Still using my scooter everyday to go to work and run some errands even though the temps are falling to the low 50s. With a good parka, good gloves and a small tuque under the helmet, no problem. Bring on the cold. I'm at 2250 km on the scooter and other than the usual maintenance like checking tire air pressure, wheel nuts for tightness and a little lubing here and there, no problems or failures to report. I wish I could talk about some upgrades I did like better batteries or controller or motor but I'm still running the thing pretty much stock. We decided not to wait to have the driveway done so that's where the money went and the family car needs new winter tires so the ''scooter modding fund'' is at zero :oops: Oh well, it still gets me there, just a little slower than I wish. On a more positive note, by running the scooter exclusively all summer, it has now paid for itself with what was saved not having a car. :yipi:

Good to hear.
 

Its good to hear that things are going well for you with your little gas saver. I am still on the fence myself about buying a scooter, or converting a mountain bike into an E-bike. And actually I am looking at a full blown dirtbike at the moment for some weekend fun time. There is a used Honda 250cc motocross bike for sale at one of the local shops here in Prague, but they want 65,000 Czk for it, which is about $3600. The good news is that because of our Diplomatic status here we get all of the VAT/taxes back on it, which would end up being approximately $1,000. $2600 is not bad for a bike like this one. Its all tricked out for racing, and has just been fully serviced. I have to do some checking with State8Honda stateside and see what kind of deal I can get from them. They send a shipment to Germany evey month and the shipping would be $300.

I thought I would put this in here. I just ordered a Razor E200 scooter for my son for Christmas.

http://ep.yimg.com/ca/I/razorama_2178_4940609

It runs on 24V (two 12V 7amp batteries) If I wanted to replace those SLAs with a couple of 6S 5000 mah lipos, what could I use for a Low Voltage Cutoff?

Or could I replace the controller
http://www.electricscooterparts.com/...K2430HB-FS.jpg
With a CC MMM and use that MMM's internal LVC? But what to do with the throttle twist grip?

A very simple, cheap solution would be a lipo low voltage alarm/buzzer like this:

http://www.ebay.com/itm/1S-6S-LiPo-B...item43aaa3aac4

The fact that you (I mean your son) is riding it would mean you (he) would definitely hear it (not like a rc vehicle at a great distance) - so it should be very reliable.

Anyway, just a thought.

Nice device, cheap, effective and simple. Thanks. But I don't get how they say it can be used with LiFe batteries if it starts screaming at the 3.3V mark (3.3V per cell I presume). But for lipo, it's looks nice.

The throttle is probably a typical 5k ohm pot. The MMM wants to see PWM pulses. Easiest way to do that would be to get a servo tester and replace the pot in the tester with the wires from the throttle. Might want to give some thought into how the ESC will react if the throttle goes bad though; I don't think you want your son to suddenly be running at WOT if something goes wrong...

He can always put a relay between the motor and controller. The brake handle has a switch that can trigger the relay to an open circuit. Or use A123's and don't worry about modding anything.

I own a few of those LVA's. They are adjustable by increments of .10 volts. 3.0-3.8 alarm voltage range per cell IIRC. Loud little suckers too.

I didn't know they were adjustable. That is cool. I'll see how good he is with it and decide then if I'll upgrade the thing with lithium. I'm scratching the MMM idea, better to keep it safe for the boy. Thanks guys.

Correction
 

I doubled checked it's 2.7-3.8v per.^

The razor scooters already have a low voltage cutoff. At 6S it should be fine. I run 7S on something similar and it works fine too, but lvc will hit at a lower voltage than you would probalby like. It probably wont work over 7S because they have a high voltage protection, but your kid will always want to go faster. The 5k pots are only used on the brushless motors. I'm pretty sure thats a hall effect throttle. I havent figured out a way to get that to talk to a CC controler. TNCscooters has some good deals on different controllers if you wanted to swap it out, but there is good info there on how they work since they have all the spec sheets.
LVC on those type controllers are around 20.5 volts according to a bunch of spec sheets and they are usually plus or minus a volt. You cant run SLA's down either or they go bad too. I've been running lipos in my scooters for a while and they work great. Those controllers limit the voltage to keep accelleration under control and keep the motor from burning up. If you put a CC controller on that thing it will probably wheelie on demand.