| Author |
 Topic  |
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
 Posted - 05/03/2007 : 11:53:16
|
I recently bought a used Razor E300, and the previous owner had let the lead acid batteries sit uncharged for a month, so they were just about kaput. Maybe 1 mile range, and most of that was spent creeping along at 8mph. Pathetic. So I ditched the old heavy batteries (12 lbs worth) and put in a couple Milwaukee V28 batteries (2.3 lbs each) which are designed to be used with power tools. At first I ran the scooter with one of them, which was very zippy compared to the old tired batteries. Even though they call them "V28", they really run at about 27 volts under full load. Still that little bit more than the 24 volts you get out of lead acid is quite a good thing, giving 15.5 mph average top speed instead of 13.5 mph with lead acid. And the motor controller didn't seem to mind a bit. But running with just one V28 battery it seemed to be too hard on the battery because it was very warm afterwards. Warmer even than the motor gets. I was able to get only 1.25 mile at full speed (about 15mph) out of that 3Ah battery. Running with two V28 batteries in parallel gave a 3.6 mile range at full throttle, and the batteries were just warm afterwards, not hot. Much less loss from internal resistance. At a much more conservative pace I got 5.75 miles. (I weigh 145 lbs, and hills were never more than 1% grade.)
Craving more distance, I changed the layout of the parts in the battery box in order to make room for a third V28 battery. To limit heat I had to cut a hole in the side of the box and mount the motor controller vertically, with its heatsink exposed to the outside. Less heat build-up in the box is a good thing. And with 3 batteries I'll get about 9 miles of range at half-throttle. (A touch better than 3/2 of existing range because it will further limit the loss from internal resistance in the batteries.) Final weight of the scooter will be 37 lbs with the 3 V28 battery packs, which is 8 lbs lighter than what a stock E300 weighs.
If anyone out there is interested in trying this same trick, after you crack open the battery (quite literally crack it open) the positive wire can be soldered right on the big metal tab found on the top of the battery. But be sure to connect the negative wire up to the braided copper output line from the transistors on the circuit board, it's the braided line on the top. You can't connect to the tab on the batteries directly because you have to include that cutoff circuit or the battery will get discharged too far and you'll ruin the pack and it won't recharge again.
Speaking of charging, I ditched the Razor charger because lithium takes a special charger so as not to overcharge, risking explosion and fire. (No doubt you've heard of the Sony LiPo battery recall! Those actually have cobalt though, not like these safer high-current manganese cells.) Anyway, to simplify charging I left the original Milwaukee connectors on all the battery packs. I currently open up the scooter box and pull out the batteries every time to charge them. Takes an hour per battery. Soon I'll ditch the standard Milwaukee connectors, and put in a 5PDT key switch that selects between running normally with all of the batteries in parallel, or charging the three batteries. Accessible on the side of the battery box will be a molex connector for each battery. I'll modify my chargers to add those molex connectors, and be able to charge all 3 batteries simultaneously, and not have to open the scooter anymore.
So bottom-line: Lithium is expensive (When it's all said and done I will have spent $385 on batteries and chargers), but if you use it alot then it's worth-it.
Anyone else out there giving lithium a try?
|
Edited by - lorint on 05/16/2007 09:51:08 |
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/17/2007 : 19:05:01
|
Yeah, I'm seriously considering it. Did you ever put on that 5PDT circuit to allow plug-in charging?
I was thinking about trying to put a whole bunch of laptop batteries in series. I've got a bunch of them from broken laptops which I take apart and sell stuff from in my free time. I've been saving the batteries for this project. How practical do you think this would be?
Otherwise I might just go for the Milwakee battery that you used. |
 |
|
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 05/18/2007 : 07:25:13
|
quote:
Originally posted by Hvatum
... Did you ever put on that 5PDT circuit to allow plug-in charging?
Yeah, and it works well. Actually ended up with two 4PDT switches, 15A per pole. One is devoted solely to negative, and one to positive. This way it totally isolates each battery for charging. Otherwise if I tried to leave either the negative common or positive common I could have gotten away with using a 3PDT for the 3 batteries, just switching one side of the battery between charge and run. But checking with the voltmeter when I had two batteries charging at the same time with the Milwaukee chargers, there was 50-100ma of current flowing between them on that common rail. I didn't like where that might go, especially with a chemistry as picky as lithium. So a 3PDT switch would have limited me to charging only one battery at a time. So I decided to take the total isolation route. Means I have to flip two switches to change between charge and run, but I don't mind. If they're in the wrong position then there's no harm.
Along with installing the switches I also put in the third V28 battery. Haven't had enough free time to test range. But final weight of the scooter is 36.5 lbs. Very convenient.
quote:
I was thinking about trying to put a whole bunch of laptop batteries in series. I've got a bunch of them from broken laptops which I take apart and sell stuff from in my free time. I've been saving the batteries for this project. How practical do you think this would be?
I think it could work quite well. I was actually considering going that route myself. I only had six batteries though, so not quite enough to deliver the current required for a scooter. And recharge time with that many batteries could be a bear.
The primary concerns with LiPo are to have enough current capacity so you're not taxing each individual cell too hard. And of course you have to have the same chemistry and cell count for each set of batteries that are in series. So you end up with a bunch of strings of matched batteries in parallel. Capacity has to be the same for any batteries in a given series, but between strings of cells you can have a different capacity in each string. In other words, you could have 6 matched cells (so 22.2 V) that each do 4Ah in series, and another 6 cells that do 2 Ah in series, and take those two series strands and put them in parallel for 6Ah total. To charge them then separate them again and charge each series string individually.
For a 24V scooter application you'd want 6 or 7 matched cells in each series, and 20Ah or so of capacity for the average 350 watt scooter. You may not get all 20Ah of capacity since you'll be draining it pretty fast, and the internal resistance of the batteries will work against you. But it should still be quite good range. Having at least ten of the 11.1V Dell batteries would be perfect for something like this. With that you could have five sets of two in series, and then probably get 8-10 miles of range or so.
It's good if you can retain the charge controlling chip that's built into each battery to avoid both deep discharge (not dangerous to you, but it kills the battery), and overcharge (dangerous because the cells will balloon up, explode, and a fire results). Also every 20th charge or so it would be good to condition the cells so they are at the same level. Fancier chargers have those balancing lines to do this.
One plus for the Milwaukee batteries is that it appears that balancing lines are actually built in! Haven't tested that part to make sure, but there are individual lines on a kapton former that run to each cell. Sometime I'll unsolder one of the lines, hook it up to a multitester, and see if there is any current is running on that line during charge. If there is any then it means either the cell is being shunted or boosted to maintain the proper voltage. (A good thing.) If not then it just means the charging circuitry is monitoring individual cell voltage to make sure none of them get above 4.2 volts. (Not as good for capacity over time, but still great for safety.)
What kind of scooter will you be running?
|
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/18/2007 : 08:41:26
|
Thanks for the great reply!
I've got eight 14.4V Dell, Compaq and Apple laptop batteries. They're pretty small so I think I could fit at least those eight in there. If that works out I'll maybe buy ten more batteries from eBay and test them out (You can get "as-is" batteries on eBay for Peanuts, and in my experience about 25% of them hold a decent charge). Here are the charges for the batteries:
3x Dell 14.4V 2.5 Ah each = 7.5 Ah
3x Compaq 14.4V 3.2 Ah each = 9.6 Ah
2x Apple 14.4V 4.2 Ah each = 8.4 Ah
Since I've got an odd number of Dell and Compaq batteries I might just put two of those each in series for a total of six batteries, not sure how I could wire them so I don't run one of them down all the way. So I'd get:
2x2.5 + 2x3.2 + 2x4.2 = 19.8Ah * 60% = 11.8Ah
(So two of each brand of laptop battery will be in series, and three parallel banks of batteries.)
I think estimating that the batteries hold 60% of their charge at this point is pretty realistic. All the laptops they were taken from had been working relatively recently, and the batteries on all of them held a decent charge. I've got the Razor E300.
What do you think the best way to go about charging it would be? It would be really sweet if I could just plug in one or two (or three) chargers and have all the batteries charge overnight, do you know if this would be possible? Thanks for all the help! |
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/18/2007 : 20:01:19
|
I was thinking, trying to wire all of the batteries with the control circuit things still attatched (inside the plastic containers) might be hard.
Maybe it would be a better route to take the batteries apart and use the individual cells? As far as I know laptop batteries just have a bunch of individual cells inside them, which are ordered from somewhere else, so they should be easy to take apart and then rewire.
Then I could use the following control circuit:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2548
This would allow me to add a pile of cells in series. Any thoughts? |
|
|
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 05/19/2007 : 02:50:33
|
quote:
Originally posted by Hvatum
I was thinking, trying to wire all of the batteries with the control circuit things still attatched (inside the plastic containers) might be hard.
Yeah, definitely. If I were to tackle such a thing, I'd consider removing everything from the casings, and keeping the control circuits on each battery. Then have switches to take each 14.4V group of cells out of the circuit to charge them, using a bunch of 14.4V LiPo chargers. That takes lots of time though for a charge. It's kinda the approach I took with my E300 actually. No worries in mine about multiple sets in series, it's all just three parallel strings of 3Ah batteries, and three chargers to match. Everything is charged in an hour, and two 4PDT switches isolate everything nicely.
quote:
Maybe it would be a better route to take the batteries apart and use the individual cells? As far as I know laptop batteries just have a bunch of individual cells inside them, which are ordered from somewhere else, so they should be easy to take apart and then rewire.
The only problem is trying to match the loose cells well enough to make a good battery. It's possible, but if one of the packs has seen lots more use then you'll have to be careful to balance the cells every few times you charge. Heck, maybe getting one of those balancing chargers would be good. Lots of lines to connect in order to charge though. But doing this does simplify everything, and cuts down on the number of chargers you have to run simultaneously.
You're getting me thinking about how to set up LiPo on the cheap! I like this. Too bad something like this multi battery charger isn't cheaper:
http://www.pc-security.com/Newproducts/Multi-Bay_Battery_Charger.html?gclid=CIKIwOeQmowCFRTCYAod1Gyg1A
quote:
... could use the following control circuit:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2548
This would allow me to add a pile of cells in series. Any thoughts?
I like the control circuit. You'd have to get three of them in order to manage everything, and then three chargers as well. The 10A discharge rate may be a little high for the smaller 2Ah batteries. Too bad that part isn't adjustable. |
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/21/2007 : 15:51:37
|
quote:
Originally posted by lorint
quote:
Originally posted by Hvatum
I was thinking, trying to wire all of the batteries with the control circuit things still attatched (inside the plastic containers) might be hard.
Yeah, definitely. If I were to tackle such a thing, I'd consider removing everything from the casings, and keeping the control circuits on each battery. Then have switches to take each 14.4V group of cells out of the circuit to charge them, using a bunch of 14.4V LiPo chargers. That takes lots of time though for a charge. It's kinda the approach I took with my E300 actually. No worries in mine about multiple sets in series, it's all just three parallel strings of 3Ah batteries, and three chargers to match. Everything is charged in an hour, and two 4PDT switches isolate everything nicely.
Yeah, that sounds like the best path. I have two chargers so I could just charge each bank by itself. It would be nice if I could just plug three chargers in for the whole night, instead of having to switch. Would it be safe to hook up each charger in parallel to like four batteries at a time?
Basically I want to set it up so I can charge all the batteries over night without having to go physically flip a switch or plug things in and out. Any ideas (Except for of course that super expensive charger you linked ;)
EDIT: In other words, how safe would it be to charge multiple batteries in parallel. |
Edited by - Hvatum on 05/22/2007 07:06:43 |
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 05/22/2007 : 15:38:10
|
quote:
Originally posted by Hvatum
It would be nice if I could just plug three chargers in for the whole night, instead of having to switch. Would it be safe to hook up each charger in parallel to like four batteries at a time?
I would charge Pb, NiCd, or NiMH in parallel without worry, but with lithium (especially LiPo) there's just too much risk. I've heard about bad things happening if you charge in parallel... Those are the ones that can explode! The lithium phosphate or lithium manganese that are used in power tools don't have this same risk. They also have lower total capacity and higher output current compared with LiPo. So there are some real trade-offs involved when choosing between the various lithium chemistries. |
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/22/2007 : 23:13:32
|
quote:
Originally posted by lorint
I would charge Pb, NiCd, or NiMH in parallel without worry, but with lithium (especially LiPo) there's just too much risk. I've heard about bad things happening if you charge in parallel... Those are the ones that can explode! The lithium phosphate or lithium manganese that are used in power tools don't have this same risk. They also have lower total capacity and higher output current compared with LiPo. So there are some real trade-offs involved when choosing between the various lithium chemistries.
Interesting, I didn't know those risks wouldn't be present in Lithium Phosphate.
Shouldn't the control circuitry in the laptop's battery prevent it from overcharging? (Assuming I keep that circuitry intact). |
Edited by - Hvatum on 05/22/2007 23:14:43 |
|
|
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 05/23/2007 : 07:44:49
|
quote:
Originally posted by Hvatum
Interesting, I didn't know those risks wouldn't be present in Lithium Phosphate.
Yeah, that's the beauty of lithium phosphate and lithium manganese.
quote:
Originally posted by Hvatum
Shouldn't the control circuitry in the laptop's battery prevent it from overcharging? (Assuming I keep that circuitry intact).
Some old ones only prevent overvoltage of all the cells when considered in series. So after lots of use one cell could still get dangerously overcharged. Hence the various fires that people have had with LiPo. Note that this is generally a concern just among older batteries. Better circuits incorporate a full balancing solution with lines that run to each individual cell, monitoring everything while charging, and cutting off the whole pack when any one cell hits a low-voltage threshhold. You would want to make sure you have those sorts of lines running around your pack, 3 small lines in a 4-cell battery. Also during the later stages of charging it would be interesting to precisely measure the voltage to each cell to see how much juice each one is getting. Hopefully nothing over 4.2 volts.
On the subject of chargers, here's a cheap way to charge 4-6 cells using a car laptop adapter:
http://www.flyelectric.ukgateway.net/lithium-charger.htm
|
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 05/23/2007 : 09:24:13
|
quote:
Originally posted by lorint
Some old ones only prevent overvoltage of all the cells when considered in series. So after lots of use one cell could still get dangerously overcharged. Hence the various fires that people have had with LiPo. Note that this is generally a concern just among older batteries. Better circuits incorporate a full balancing solution with lines that run to each individual cell, monitoring everything while charging, and cutting off the whole pack when any one cell hits a low-voltage threshhold. You would want to make sure you have those sorts of lines running around your pack, 3 small lines in a 4-cell battery. Also during the later stages of charging it would be interesting to precisely measure the voltage to each cell to see how much juice each one is getting. Hopefully nothing over 4.2 volts.
On the subject of chargers, here's a cheap way to charge 4-6 cells using a car laptop adapter:
http://www.flyelectric.ukgateway.net/lithium-charger.htm
Ah, thanks for that article. Very interesting!
Cheap and dirty: So basically, if I trust the protection and safety circuitry in the laptop battery packs then I could just charge them in parallel using one charger. Then each battery pack would take itself out when fully charged. If they are well designed battery packs then they will reach this state when any one of their cells hits maximum voltage. If they are older then they may only hit this state when the pack as a whole reaches maximum voltage (so if one of the cells is dead I run a serious risk of destroying all off my batteries and electronics).
Optimal but complicated: Arrange all of the 24 cells separately and have over and under voltage bypasses for every individual cell. Then charge all cells individually to, using the "Fly Electric" charging scheme.
Is that about right?
Hmmm, maybe I could just check out the internals of each laptop battery and see if they've got the requisite lines running to each battery? (as you outlined, 3 for 4 cells). Hopefully they do! :D
PS: I don't think there's much of a safety risk at all since the batteries are inside a securely closed metal compartment. But the cost of replacing everything is by itself enough motivation to want to do this correctly. |
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 05/27/2007 : 03:01:11
|
quote:
Originally posted by Hvatum
Cheap and dirty: So basically, if I trust the protection and safety circuitry in the laptop battery packs then I could just charge them in parallel using one charger.
Generally, yes. The cells would likely be at the tip-top of their charge potential (4.2 volts), meaning you'd get a little longer runtime, but perhaps fewer charge cycles overall. It could work, and apparently cheap replacements are always available on eBay.
quote:
Optimal but complicated: Arrange all of the 24 cells separately and have over and under voltage bypasses for every individual cell. Then charge all cells individually, using the "Fly Electric" charging scheme.
Definitely complicated! Detaching all those batteries means lots of switches / connectors.
If there's any way to add another parallel string in your mix then I'd do it. Lithium cobalt really shouldn't be discharged at more than about 1C, so 3 to 4 amps with each string of your batteries. Another group of cells would even out the discharge a little more, and boost the lifespan of your cells.
The more I look at it the more I'm intrigued with the setup, and thinking about putting together a system based on 11.1V 45 watt-hour Dell batteries. I've got a slew of them.
I've also been looking into lithium phosphate more lately (the cells done by the A123 guys) and that technology looks better than lithium manganese. Same capacity, but more charge cycles, and much less to worry about with overcharging. Also they don't break down under heat, like my spinel batteries. It looks like the best of all worlds, and probably the battery that ends up making its way to many electric cars in the coming years. |
|
|
|
GoFaster
Starting Member
22 Posts |
Posted - 01/25/2008 : 06:00:24
|
I know this is a 8 month+ old thread but Lorint if your still out there I was wondering about the longevity of the milwakee battery set up.Are you still running it and how has it held up for you?I"ve got a minimoto maxii and was thinking of upgrading to a 48v controller and 4 milwakee bats, 2 sets of parallel in series for ~54v what do you think?
uh,dad is it supposed to smoke like that? |
|
|
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 01/25/2008 : 07:21:32
|
quote:
I was wondering about the longevity of the Milwakee battery set up. Are you still running it and how has it held up for you?
Two thumbs up from me. I've been lots of places with this scooter now. Have taken it to Ireland, the Netherlands, and from coast to coast in the USA. I bring it along when I fly so I don't have to rent a car. (When the weather is good anyway.)
The rig was entered in the Maker Faire in Austin, and chosen to be a part of the show. That was fun.
These days after having been through about 100 charges I get about 6.5 miles per charge, and I weigh 140 lbs. Of course YMMV.
quote:
I've got a minimoto maxii and was thinking of upgrading to a 48v controller and 4 milwakee bats, 2 sets of parallel in series for ~54v what do you think?
I think it would work great. Constant great torque for sure. And very little risk of frying anything.
I've also heard great things about the A123 / DeWalt 36V batteries. They really kick out about 33 volts each, not 36. So if you're daring, maybe you could try 2 of those in series. 66V! Fun stuff. How expensive is it to get another motor controller, anyway? :)
-Lorin |
Edited by - lorint on 01/26/2008 08:05:20 |
|
|
|
GoFaster
Starting Member
22 Posts |
Posted - 01/25/2008 : 16:23:00
|
TNCScooters.com has 2 48v controllers $35 and $45.I'll probably go with the $45 dollar one because it will push up to 100amp,the other is good for 50amp.The 50 is prob all I need for this , but there's no telling what kind of monster I might create in the future
Thank you for the info on the batteries I'm glad they are working so good for you! They are going to be alot easier to wedge in the frame of my maxii than SLAs.
uh,dad is it supposed to smoke like that? |
|
|
|
Hvatum
Starting Member
Minneapolis
MN
15 Posts |
Posted - 03/12/2008 : 20:09:45
|
If anyone's curious, I ended up dropping upgrading the E300. The battery space was getting to cramped and it was too difficult to add a more powerful motor on.
I ended up completing the project on an X600. The range is very good, I've not driven it to it's limit but I've got at least six miles without a noticeable drop in performance. I got all the control boards from batteryspace.com. |
|
|
|
gameboy
Administrator
just north of austin
tx
USA
1140 Posts |
Posted - 04/14/2008 : 04:47:56
|
i am, thats awsome. the 300 is kinda small.
"FREE" is always better
minimoto jeepter
razor e300
pukka gx400c
electric riding mower project( not fininshed yet) |
|
|
|
|
|
dec7td
Starting Member
2 Posts |
Posted - 04/23/2008 : 11:36:21
|
lorint,
So are you charging these battery packs in parallel using the Milwaukee charger? I've read through the thread and I can't quite determine which method you went with. Thanks.
~Dan |
|
|
|
lorint
Starting Member
Phoenix
Arizona
USA
10 Posts |
Posted - 04/23/2008 : 16:31:13
|
quote:
So are you charging these battery packs in parallel using the Milwaukee charger?
Actually they're charged individually, and discharged in parallel. This way it can charge faster, but more importantly it's safer for the batteries. Less risk of any one cell getting over-voltage.
In order to change from parallel to individual batteries, I have two 4P2T switches. One switch for positive, one for negative. I should create a circuit diagram and post it on my blog to make it clearer. |
|
|
|
colinear
Starting Member
6 Posts |
Posted - 10/04/2008 : 05:56:03
|
quote:
Originally posted by lorint
quote:
So are you charging these battery packs in parallel using the Milwaukee charger?
Actually they're charged individually, and discharged in parallel. This way it can charge faster, but more importantly it's safer for the batteries. Less risk of any one cell getting over-voltage.
In order to change from parallel to individual batteries, I have two 4P2T switches. One switch for positive, one for negative. I should create a circuit diagram and post it on my blog to make it clearer.
Wake up and roar! |
|
|
|
choppergirl
Starting Member
Mesa
AZ
USA
1 Posts |
Posted - 03/24/2009 : 13:06:52
|
CHOPPERGIRL DESIGN BIKE
I took have a Razor e300 (stock) which I got for free, which with its big tires works well on dirt. However, just looking at it makes me think the thing was design with steel, as cheaply and as durable as possible for the masses, which makes it HEAVY. Not really what I want to have.
The design I want to do is something from scratch which happens to look very close to the Diggler http://www.digglerstore.com/scooters_electric_01.html except without the insanely expensive parts.
After looking at it, it hit me, I could make one identical on the cheap with nothing but cutting up one of those tiny kid bikes (you know, for 3-5 year olds with the same size tires) you can get for free or at goodwill for $20, and doing some welding to make a custom frame. Reuse the front wheel, back wheel, front forks, and just weld up a little frame to stand on going to the back wheel with the salvaged front forks from the kids bike.
I even had 3 of these kids bikes I gave away to my neighbors and now regret. I think I'll get them back.
After that, I just buy the motor and batteries.
I want to mount the batteries under the floorboard as low to the ground as possible, and most of the weight under the axles, so when you let go of the bike it will remain standing and you won't need a kickstand. If it won't do it with those small tires, keep trying larger tires with a higher axle height until it will finally stand up on its own (if you push it, it will weeble wobble back and forth but right it self). I'll probably put a quick fork lock on it to keep the front wheel straight so it will do this (stand up), and double as a lock to keep anyone from stealing it.
Unlike the razor, I want my on/off switch on the handlebars, and the charger built in with just a plug dangling out where I can plug any plug into. I don't think a charger circuit would weigh much and I'm willing to do that to have it anywhere.
I would prefer to build mine out of aluminum... harder to weld, but worth it I think, and its not like you need much aluminum. Use as many alluminum parts as possible because they don't rust and are lightweight and strong.
Please post lots of pictures and information about your revised power setup and the charging circuit. I think in the beginning I would use the stock power tools battery charger to recharge the batteries, and have the batteries so they just 'drop in'... so if you ever have to replace them they are not hard wired into the bike. Or you could carry (3?) extra in a little bike rack on back over rear tire.
CHOPPERGIRL's AIRWAR
http://choppergirl.air-war.org |
|
|
|
|
|
Storm
Journeyman Modder
Australia
447 Posts |
Posted - 03/24/2009 : 17:32:52
|
Cant wait to see the results choppergirl it sounds like it is going to be a monster. Have you built any bikes or scooters before? I have found aluminium is quite hard to weld unless you have the right equipment, if you build your scoot from old bikes it will be of simmilar wieght to the e300 if not heavier, I have built an electric trike using aluminium which is riveted together, it has held together well and I have given it a bashing. Welding aluminium can cause large HAZ and can seriously compromise the structures if not done correctly, if riveted you avoid this problem and you can use stronger lighter 7000 series aluminium which is very hard to weld.
This is an old photo, the trike has been modified some since but I'm sure you get the idea of whats possible with limited tools :)
 |
|
|
|
Storm
Journeyman Modder
Australia
447 Posts |
Posted - 03/24/2009 : 17:38:38
|
More recent.
 |
|
|
|
Old_Scoot
Journeyman Modder
Paducah
KY
USA
277 Posts |
|
|
Voltron
Starting Member
Arus
Far Universe
47 Posts |
|
|
|
| |
Topic |
|
Lithium manganese batteries rock!
