1500W 48V Ebay kit, Advice for noob.

[ScooterMan101]

Power tool batteries are not known for being able to pull many amps continuous .
I am tired right now , the Battery Section is a good place to read up on Batteries.
I have just started to use Hobby Lipo's , but they come with many concern's . The Battery Section has plenty of threads for Reading.

I am not using Outrunners,
I started off with a Mac 6 T Geared motor, and now also using a Q100c CST 201 Rpm motor.
Neither motor will give fast speeds like what you want unless you up the Volts, and Amps, however on the small Q100c you can only up the volts, I have heard that over 17 amps will kill it real fast.
Both motors on 12s/13s/14s only produces 20-23 Mph, I will be experimenting with higher volts on the Q100c in a month or two from now to get a little more Mph. But am unsure how long the motor will last at higher voltages/higher speeds.

That why I have an eye on what Kepler is doing, He understands what is needed to get beyond 22-23 mph limit of many motors . ( 37-39 kph )

Every week someone comes new to E.S. and says they want to get to 50 Kph, but it is not easy, there is allot of tweaking on your part to do so.
You need a very large/heavy Motor , plus a large and heavy battery that is also able to deliver 30 amps or more.
Or
you need to do what the Pro Road Bike Riders do, Get the most efficient / lightweight bike you can , and get as best aero position as you can.

What out runners are you using? I see they do have very high continuous power ratings. I guess it's the high temperature windings (one I looked at was 300deg c) and the fact the ends of the motor are like fans to pull air through it. I have a cnc machine and could make the required mounts for it in a day probably. I'm just not sure I trust such a small motor. Not to mention it'll be a lot more money, the 3kw one I was looking at was 400 dollars + the speed control mount throttle etc.

Not sure why you think I can't pull 10c out of my battery, have you looked at quality high power cells from A123 and the like? 10c is a walk in the park that's 100 amps at 60v 6kw. I think you are to used to seeing junk batteries on ebay that are only good for maybe 2C discharge. I'll run a discharge test on it when I get home. Like I said I'm time poor at the moment, I've just had our first child.
You have got my interest and I'd like to play around with it at some stage. The brackets would be pretty easy to make I'd do it a bit different out of some 10 or 12mm aluminium, more rigidity.
Yeah it's hot here hits over 40c quite often so it'd be a good work out for it. Mind you if they are running winding temps really high the ambient isn't going to effect the cooling much.

 

[Dauntless]

http://www.ebay.com/itm/26-Folding-Electric-Mountain-Bike-Bicycle-Ebike-W-Lithium-Battery-250W-/282162974278?var=&hash=item875911cce8

Okay, no love of fatbikes, eh? What about mountain bikes? This isn't so much a build or conversion as an upgrade. But look at this thing, just $524. Or is it $459? I note funny things go on with this one. But isn't that a fabulous bike? ALREADY ELECTRIC.

Except what were they thinking? Only 250w. And you need a disc brake wheel for the upgrade. Hopefully this other one does fit.

Chinese junk or no, I think this could be pretty darn effective for the price.

http://www.ebay.com/itm/48V-1000W-Electric-Bicycle-Cycle-E-Bike-26-Conversion-Kit-Hub-Motor-Rear-Wheel/262853470891?_trksid=p2047675.c100010.m2109&_trkparms=aid%3D2220072%26algo%3DSIC.MBE%26ao%3D1%26asc%3D41394%26meid%3D2be569388a664351a72fcdd88dd21bb4%26pid%3D100010%26rk%3D3%26rkt%3D6%26sd%3D122362096947

 

[wesnewell]

if you're going to be pulling 5C discharge, then most 18650 will choke on it. A lot of them will choke on 2-3C. One of the best 18650's, Samsung 25r, is only rated at 8C, and many are rated for only 2C or less.For a 5C draw, I'd look at rc lipo from HK Au warehouse. 10C or higher discharge rating.

 

[2old]

I don't know much about "C" rate (always need to look it up when figuring out anything) and even worse have only had a brief, but unforgettable, encounter with "DD's", but my YES kit with 52V, 10 a/h Luna battery has been happily buzzing along at 32 mph for the last year and does double duty by powering my BBS02 MTB (keep expecting the battery to sag like the "DD's" probably are by now, but it doesn't).

 

[cycborg]

But look at this thing, just $524. Or is it $459? I note funny things go on with this one. But isn't that a fabulous bike? ALREADY ELECTRIC.

I'm really confused. I mean, I appreciate that they provide an explanation of what those mysterious headlight thingies are for, but then where the headlight would normally be mounted, they show a fire extinguisher. :?

 

[pas940]

My kit got here today, all looks ok to my untrained eye.
Spokes look a little loose. Other than that I haven't touched the wheel.
I opened the controller it's using an infineon xc836. Looks similar to some of the old infineon stuff here, I think I can see where the processor samples the pack voltage and the opamp for the current shouldn't be too hard to work out. The shunt is soldered from new! name plate is 26+-1A at 48v has 63v caps and 12 x 100n07 mosfets so not much point going too far with this as everything will need changing hopefully I can run 15S I'll just charge to 63v
Uses a switch mode reg to 15V which is different to the old threads here I was looking at.
has the code eb12a1 on it.

Just got to get the aluminium sheet for the battery box sorted, plan has changed I going to close in both sides of the triangle and fit bat and controller in there hopefully.
It's tempting to go the duct tape and cable ties route but I know if i do that i won't want to redo it right.

I'll see if I happy but I might upgrade controller and go to 20s after it's all going, depends how I feel with it.

 

[pas940]

So looking at a controller upgrade,
When you see a controller with advertised normal voltage, say 72 volts is this assuming 3.7v per cell ? So say 72/3.7 = 19.45 would this be good for a 20S pack? Say 4.2v x 20 = 84 volts when hot off the charger?
looking at this:
http://www.ebay.com/itm/48-72V-1500W-Electric-Bicycle-E-bike-Scooter-Brushless-DC-Motor-Speed-Controller-/302066880207
How do they get those numbers I assume that's a 48A current limit. But even at 48v that's 2kw. Also how does undervoltage cut work with a large range of input voltages like this?
Any advice appreciated.

Found this data for my cells:

 

[pas940]

Just took the bike for its first run with only 73 volts (storage charge) I hit 60kph! super happy with that. I'll have to do some more runs soon. Have to balance the pack and charge it fully then I'll be excited to see what I can get out of it.

 

[pas940]

Quick update, I've finally got to balance the pack and take it for a run. 73kph. Still on off road tires so I'm guessing there's more in it.
20s 4p sony vtc5. 4.18v per cell down to 3.85v after 6.9km with average speed of 40kph peak speed of 73kph!
Have my bulk charger running at just over 10A to 82v cut off. Balance was a little slow but that's only going to happen every so often.