I've been lurking and learning here for months. This is my first post.
Recently, I acquired a GT Shockwave. I'm the third owner after 2 teenage boys. But, structurally it seems sound; cosmetically (and to some degree functionally)it's a mess. In other words: It's ripe to mod!
I've been considering going all the way to 48V for this one. I'm okay with everything I need to change, but it's sure a lot of lead to stash on there somewhere (non-sla batteries are not a budgetary option). I'm not willing to raise the foot deck, since I will be riding this standing-up and find the handlebar height nearly too short as it is. Sounds like it needs to be a battery box under the frame. Anyone ever done this? Does anyone make battery boxes that might work for this?
My objective: I'm not interested in high speed. But I do want quick acceleration, and some respectable range when cruising between 4mph and 12 mph. I don't need to go faster than 15mph, but need to be able to accelerate as quickly as any dog walking/running next to my scooter. I normally run about 1/3 - 1/2 throttle for about 30 minutes, then onto the charger and may use again after about an hour of charging. This may happen twice per day during good weather. I'd like to still have some "spunk" left at the end of a typical 30 minute run.
My question: Given my objectives of acceleration and range, what combination of battery voltage & Ah, controller, throttle, and motor, would you recommend? Guess we should consider gearing as another variable?
I appreciate all your responses.
Harlow
Actually, gearing would be the determining factor for this.
Stuffing 48V of batteries in the thing without changing anything else (except the controller of course) would normally give you double(?) top end and similar (if not faster) acceleration you had before. Gear it down to half of what it was, and you will have the same(?) top end and probably enough torque to do wheelies, not to mention conquer any hill you can find.
As for the batteries, do whatever you will. I'd replace the pack with whatever size I can fit in the thing. Since you aren't geared to go very fast (15mph isn't anything; I plan to do more on my skateboard), you can floor it all you like and get phenomenal range with relatively small batteries. I have a thing for 18Ah 1/2 U1s for their odd dimensions, myself. Not the cheapest for the price (that prize goes to the big 35Ah U1s), but not too expensive, either. I think the most common are the 7-12Ah size, but go bigger if you can afford/fit it.
Are you sure you wouldn't want lithiums? They are only 2-3 times more expensive (around a dollar a watt hour), but should have around 4-5 times the cycle life.
The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai
Thanks LinkOfHyrule.
I don't mind experimenting with gear ratios. The Shockwave has a 15T front and 90T rear sprocket. Where could I get a smaller drive sprocket with a freewheel in it?
Looks like I could easily fab a battery box similar to the stock one, just deeper, and "hang it" between the frame members. Should be able to easily get (4) 12V 10Ah's, or (3) 12V 12Ah's to fit. Which do you think would be a better option? I'll have to buy a motor and controller anyway. Any advantage in 48V vs 36V when we are mostly looking for low-end power? Or is this one of those, "it depends" questions? Like, which motor are you going to chose?
for more power, there are several options. I like the Powerpack motor set up run at 48 volts. Good hill climbing, great top end. Very easy to install.
http://powerpackmotors.com/Powerpack-enhanced-shipping_included.html
You want range? The 48 V 20 AH LiFepo4 packs have come way down in price and are now about $500. I just put one on a similar scooter to yours, a Lashout. That scooter went about 7 miles on 12V 10AH batteries, it goes 20 with the Lithium pack, and it goes most of the range at full power, as the voltage does not quickly fade like LA batteries. You need a battery box that will fit 14 X 6X 4 inches to fit the Lithium pack I run.
Sorry, I didn't catch the part about no lead acid substitutes. Be careful boosting the voltage on any of the Currie made scooters that have built in controllers. You will overheat and ruin the controller/motor in short order. If you have the 600 watt brush motor with a separate controller, you can get more torque & power out of it by running a higher amp controller and boosting the voltage to 36. here is some info about that.
http://www.cloudelectric.com/inc/sdetail/214
"EV Deals" sometimes has ready made battery boxes/ People also remove the stock box and mount it under the frame to get an extra 1 inch clearance. B&B make a compact 12V 15AH battery the same size as the 12V 12AH ones. 3 or those would give a decent range.
http://www.evdeals.com/Order_form.htm
B&B batteries, scroll down to find them
http://www.electricmotorsport.com/PARTS/parts.htm
Good luck . those are fun scooters and can be made to ride quite nicely.
Afraid I can't really help you with the gears. I don't think you can just go out and buy a 7 or 8 tooth sprocket.
Regarding the batteries however, I would definately choose the four 10Ah ones. Simple math:
12(V) x 10(Ah) x 4(number of batts) = 480 watt hours
12(V) x 12(Ah) x 3(number of batts) = 432 watt hours
10% less capacity with the three 12Ah batteries. Plus, when you factor in that the peukert effect will be (slightly) less noticable because you're drawing less amps, and the fact that you'll get less ohmic heating for the same speed, it's really a no brainer.
The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai
Thanks for the analysis on the batteries. So, it's all about the Watt-hours? I'd be even better off then to go with (3) 12V 15Ah which would give me 540 Watt-hours? Just so happens to be the lowest cost per Wh using the BB prices.
It's cold here in Denver in mid-January. I could use a little of that ohmic heating right now.
Harlow
Thanks andys for all the links and suggestions. I have considered going the PowerPack route. Haven't nailed that decision down yet.
I said I was limiting this to SLA's for now, but I'm intrigued by the LiFePo4's. Having performance for longer than just the first few minutes is very appealing. What would be a reliable source to get a current price and availability estimate?
I just bought a new Lashout Scooter in October of 2007. Very nicely built, but it's a snail. Significantly slower than the Schwinn Stealth 1000 I bought in May. I had my Lashout out today, right after a fresh charge. I could not keep-up with my German Shepherd, and he was only in a fast trot going up an ever so slight incline. I need more power! I picked-up this old Shockwave as my "test-bed". Once I find a good combination in it, I might transfer that to the Lashout and Schwinn. But then they would all be the same and that is way boring.
Hoping to post a photo or two of the Shockwave (before pics)soon.
Someone spilled about a cup of cream-colored house paint on the swing arm, tire, spokes, chain, brake drum, and kickstand. A tedious cleanup job.
A little closer look at the mess ...
My Lashout will go over 30 MPH on the flat, and climb over 20% grades with the Powerpack motor set up. I run a 48V 20AH LIFepo4 battery I got from Ping Battery on ebay
http://stores.ebay.com/PingBattery_W0QQssPageNameZstrkQ3amewaQ3amesstQQtZkm
that pack gives me a 20 mile range, and lets me to drive at full speed for most of that range. I joke that it is no longer a scooter, but a moped at this point. I also upgraded the rear brake to an Avid BB7 disc.
A friend of mine just bought 2 Kolmorgan 400 watt brushless motors on closeout sale and is going to run a twin engine set up on his Schwinn Missle. Our aim is to get about 22 MPH top end, but with hard acceleration.
For the money, that powerpack set up is a great deal and an easy conversion. I hope Tim continues to make it for a while.
Forgot to mention I had to make a new battery box for the Lashout, as you can't fit anything in the stock box.
If you go with the motor from PowerPack they also have a complete kit for scooters. This kit has 2" aluminum risers. With this kit you would not have to make a custom battery box. Check you the link below for pics and more info.
http://powerpackmotors.com/Complete-swingarm-modification-kit-info-and-photo-page.html
Andy so how Does Ping's Lithiums work better than Yesa's? By the way three 22 AHRs will fit three under the deck easly with a new battery tray and fit one more under the back lid. I just went to the Electric Drag races today in Barona Speedway here in San Diego. I did the 1/8 mile in 15.1 seconds with top speed of 38 MPH with my dual power pak 55 amp motor Lashout.
Regards Jeff Storey
Hi Jeff:
That battery from Ping is amazing. I did another distance run with some killer long hills the other day. It did not cut out ever. After the 8 mile ride, the battery pack was still at 52 volts!
I am in the process of building a custom electric bike and am going to use the 48V 12AH Yesa pack on the bike. I already found the perfect padded canvas bag for the battery at performance bike-you'd think it was made for it. It will attach to the rear rack. The bike is a 20 inch wheel full suspension folder that KLH put out a few years back. I bought the new BMC planetary gear rear hub kit from EV Tech.
http://www.texaselectricbikes.com/catalog/brushless-geared-motor-p-163.html
I am going to run a 48V 20amp Crystalite controller (instead of the 36 volt stock one) which will bring the power up to where I should be able to go about 25 MPH even with the 20 inch wheels. The hill climbing ability of that hub is supposed to be unmatched. Total weight of the bike with battery should be about 50 pounds. The Yesa pack I got from you should be a perfect match for this kit and I expect 20 miles + range even with the hills we have here.
I just got a reply back from Scott @ EVDEALs. He no longer makes custom battery boxes.
Looks like I will need to find a local metal fabricator.
a heating/sheet metal place can bend up a box without much trouble. You just need to give them good dimensional drawings. Another trick we did was to get a slightly longer rear shock from Electric Scooter Parts dot com, so there was an extra inch or more of ground clearance to make up for the lower battery tray. You can fit a tray about 14 inches long by 6 inches wide by 5 inches high.
I never really thought about the rear shock. I'll keep that good idea in mind in case I need the extra clearance. Thanks.