range/power boost Stingray electric

[dsljohn]

So, my wife is 5' and about 100 pounds and I'm a foot taller and 100 pounds heavier than her. I want to build a bike which we both could ride with a little adjusting. In my hunt I've noticed that the electric Schwinn Stingray is selling for about $200 these days, I know the fake plastic engine is cheesy, but I was thinking that I could remove it and in its place put in some box which could hold 3 batteries and bring the voltage up to 36 to increase the range and boost the power.

Anybody here have experience modifying the electric stingray? I've seen the Red Hornet, and it looks bad-ass, but much more than we need. I am hoping to keep the original hub motor and just feed it more juice, I'd like to get the thing up to 18mph and increase the range.

 

[Dee Jay]

I'll buy the plastic engine and the exhaust pipes off ya! 8)

30 bucks?

J

EDIT: Damn, too tall . .

 

[dsljohn]

Oh, that's too bad...

So, assuming the motor could handle 36 volts what controller and battery setup would you all recommend on a budget? NiCad the biggest bang for the buck? How much battery do you think I'd need to get 20 mile range at 15-18 mph on flat land? I'd like to keep the total cost under $600 if possible.

 

[Dee Jay]

Hi dsljohn,

No guarantee other controllers will work on that motor.

If you take the chance overvolting the stock controller be prepared to spend more on a kit

If you burn out the stock motor, you'll have to install another motor on that wide rim, but will the stock spokes fit a different motor?

36volts was great when my Nimh pack was fresh but after several months the pack weakened and 36v just wasn't worth a damn on 20" wheels. Now I'm running 50+v on my 36v 20 amp controller. And so far so good. I was taking a chance of burning out my controller so I installed a temp sensor inside the controller to monitor the temp difference between 36v 9ah Nimh pack and 48v 2.3ah 14s A123 pack. Not a much at all, so I took another chance by adding another A123 cell making 15s 52 volts AND I'M LOVING LIFE! Will double the Ah very soon!

The Stingray would suit your wife's weight, but for a 200 pounder, you'll need a lot of power / $$$$

Unless someone can pass on their experience overvolting a Stingray, I would rather build on a non electric Stingray.


J

 

[Link]

No guarantee other controllers will work on that motor.

What sort of hub that thing got? If it's brushed, you can get another controller to work with it, no problem. You might have issue finding a brushless controller if it doesn't have 120° spacing, but I doubt it does. I'm betting it's brushed, anyway; never seen a brushless motor on something that cheap.

20 miles at less than 20mph is a cakewalk. A 36V 15Ah should do the trick (assuming not SLA), and with power to spare. Shouldn't be hard to find a pack like that for under $600.

I don't know how long that hub'll last if being ridden a lot, though. Or even if you can find brushes for it. :?

 

[dsljohn]

Thanks for the input guys. I'm also considering just buying a ready electric hub kit which would cost more $ but also insure that the stingray would have enough power for me. The thing that I'm worried about if I do that is the 170mm dropouts on these things, anyone know of a hub motor that would fit?

 

[Link]

The thing that I'm worried about if I do that is the 170mm dropouts on these things, anyone know of a hub motor that would fit?

Pretty standard width. A rear 4XX Crystalyte would do nicely. My rear Golden motor (5 sp freewheel) just fits in the 170mm drops of my S40. What size rims does this thing have? A Golden on 48V will give you exactly 20mph in a 20" rim. It'll cost you more than a 4XX, but it's brushless and quite torquey. It would have great pickup in a 20".

 

[dsljohn]

Apparently the motor *is* brushless according to this thread:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=3701&p=54975

It's a 20" rim. I like the kits that Golden has to offer it takes the guess work out of the job for someone as green as me.

If I could read those specks right it looks like the stock Stingray controller is good up to 40V? If so shouldn't I be able to hook up a 36V pack to it?

This is my thinking right now, run it with a 36V battery pack until I fry something then jump up to a quality hub kit like the Golden.

 

[Link]

Brushless motor?



Well, whaddaya know? Didn't see that coming.

40V spec is a bit marginal for a 36V pack, as the batts will read that or even slightly over that when fresh. I'd give it a try, anyway. It'll probably survive, albeit at the cost of a lessened service life. If it doesn't live, either upgrade the controller or get a kit.

 

[bbsux]

I have a stingray electric...

Its a brushless motor.

Schwinn tried to save some money and had the engineers design it to be either 24 or 36 volt. The battery "engine" has room in it for a third battery and the controller works with it too. The motor is also the same motor that the company would use at 36v with another label.

The stock seat is a real pain.

 

[dsljohn]

Thanks for the confirmation BBsux. Did you run 32V on the stock motor & controller? How did it do?

 

[bbsux]

Yep ran it as is. simply found another 12 ah battery wired it into the pack.

It went 5-7 mph faster with better torque... I've since switched to a better controller and am still using the motor at 36 volts with no problems... over 500 miles...

 

[dsljohn]

Thanks BBsux. it seems like quite a bargain then @ $200.

 

[stingray323]

I bought the electric stingray on ebay I had researched these for a while and realized a strinray has all the needed parts to go for a ride as is.
since the glory or electric bikes has improoved in the past three years 2005-2008 the cost is a fraction of the other newer models.
I find that I do want to add another 12 volts. so this forum topic is exactly the right one for me to study. the ananda motor and controller are set to 24 volts but some guys in canada have run as many as 48 volts.
if another controller is used the color codes may be different that seems like the only drawback to look into.
I live at the top of an extreme hill. I can peddle right up the hill on a fully charged battery on 24 volts.
I had planned on adding a 12 volt 9.5 amp hour battery that I found. it is like new and I now realize it could fit inside the engine case. thats perfect. no more external clutter. by removing my seat I can clean the chrome faster and I did move the rear reflector down the the wiring cap on the rear frame that way it is easy to wipe down the rear fender.
the chrome pipes are off now too that way I can access all of the parts on the rear. weight wise I think the seat is too heavy and the pipes as well. I want to buy an older style stinray seat that will reposition me back a bit to make pedaling easier at present I sit on the chrome handle to make those sttp clmbs by pedal assist. the bike is perfect for a six foot man and it will hold 300 lbs WoW. get a stingray asap they have been designed to take us to the future for cheap.

 

[davespicer]

Thanks BBsux. it seems like quite a bargain then @ $200.

Or $150, if you can find one in a store...

 

[stingray323]

where to buy a stingray delivered to your home in a 100lb box ,3 day lead time to get one. On ebay look up the "electric" stinger, and bid $ 240.00 you will win the bid, then call em, and they ship it real quick from Lincoln Nebraska, "the last house on the block for this white elephant". (the only draw back is there are only 44 left in the USA so act now, dude its guarteed for 5 years) a Schwinn bike box is dropped off at your door just like christmas ,You can see the quality in every bolt ,its a winner/// just put on the front fork tubes and front wheel and pedals and you can charge it for 20 hours the charger will need to be a 36 currie to work with three batts thats 18 bucks the spare battery is 25 bucks ,,,you have your 20 mile range and speed easy
I have gone on the road for hours putting on sunset blvd in hollywood andthe 24 was just a bit weak on the end run up hills. and had to walk beside it while it pulled me up the steep hill like so easy. the 12 more volts make the range farther don't waste money yet on some $600.00 kit,, its chineese and sucks, very wierd people put the little cells in their front fork tube's so the front fork is the power ,36 or 48 volt fork tubes "Who Knew"?

 

[dsljohn]

Stingray323, where did you get your compatible 36v currie charger from? Thanks.

 

[Link]

SLA charger? Get one from eBay or TNC Scooters or something. They pretty much all have the usual 3-prong plug.

 

[dsljohn]

Thanks Link. So, I guess the question is will three 12V SLA batteries be enough to get me 20 miles at 15-18 mph? Anybody know the Ah of the stock batteries?

 

[dsljohn]

So, my electric stingray came in yesterday. I had it assembled and the batteries on the chargers within an hour. It isn't as small as I faired, with the seat extended I still could peddle it fine. The frame seems really solid and I like how the batteries sit very low which gives it a good center of gravity. Ride wise it is really fun to put around on, but I do wish it was faster.

I am going to upgrade to 36V. I am considering two approaches:
1 just add a third 12V SLA battery as outlined by BBsux and buy a 36V charger. It looks like I could get that done for about $100.

2 Get the 32V 10AH LiFePO4 pack at $365 from goldenmotor.com

Could someone who is good at the emath tell me if 20 miles is possible on this bike with a 10ah 32v pack?

 

[TylerDurden]

Could someone who is good at the emath tell me if 20 miles is possible on this bike with a 10ah 32v pack?

I'm not good at any kind of math, but you might just make it without even pedalling...

You would have 320Wh of capacity
It takes about 300W to go 20mph
In one hour, you would go 20mi and deplete the pack.

Going slower would be even better.

If you pedal, no problem.

 

[Link]

Could someone who is good at the emath tell me if 20 miles is possible on this bike with a 10ah 32v pack?

I'm not good at any kind of math, but you might just make it without even pedalling...

You would have 320Wh of capacity
It takes about 300W to go 20mph
In one hour, you would go 20mi and deplete the pack.

Going slower would be even better.

If you pedal, no problem.

Yup. But I doubt the stock gearing will even leave him able to.

And what 32V pack? I only see a 36. In fact, it's not possible to make a 32V pack out of 3V nominal LiFe. The 36V pack should be able to do it, but only if you pedal; Tyler's right about the distance at full speed, but there's quite a bit of energy lost in getting the bike up to speed when the motor's in a not-so-good RPM range.

And that's a pretty decent price on a lithium pack even if it didn't have the charger, now that I look at it...

 

[dsljohn]

Sorry, that was a typo, I meant to say 36V. Thanks again for the help. I'd like to have plenty on reserve. I might go with two 36V 8Ah NiCad from ebike.ca. Its kinda hard to find a 15ah pack at a reasonable price.

>stock gearing
Yeah, I think you are right! Even at 24V I am having a hard time keeping up with the motor. Still, I'd like to be able to assist, so I'm going to have to do something about that.

 

[docnjoj]

Ping will have packs in multiples of 12AH including 18 Amps after the Olympics. Might be worth the wait!
otherDoc

 

[dsljohn]

Thought I'd do a follow up. I got impatient and bought the GoldenMotor 36V 10ah Lifepo4 pack. Today I pulled out the plastic engine with the 2 12V lead batteries and strapped in the long lifepo pack with some bungee-cords.

I know some thought the GM batteries weren't that good because they have a low max discharge rate, but I figured it would be a good match for this system which isn't designed to have a lot of power.

Switching to a 36V system has made a world of difference, its actually peppy now. I road it around like a little kid in a parking lot today for a couple of hours doing sharp turns and figure-8s as my 9 year old practiced her bike riding. The handling characteristics on the stingray are really good at higher speeds. The only real issue is that (as predicted) I can't assist the power at top speed, I can't pedal that fast.