Upgrading my controller and battery, suggestions?

[Baron]

This is my first e-bike build and my first post on E-S. I've been lurking for a while for advice and I built my first bike thanks to some helpful threads around here.

I have an xcceries 1000W 48V kit from ebay. I believe this kit is similar but probably not the exact same: http://www.ebay.com/itm/48V1000W-26...857?pt=LH_DefaultDomain_0&hash=item5672940991
Mine came with an lcd display panel for speed, battery, distance, etc.

I paired the kit with a 13S 11P battery pack built out of 18650 laptop cells. In retrospect this was probably not the best option but it was the cheapest route, and i had some previous li-ion experience. Built the bike and everything has gone smoothly for the past few months. But I have been planning on upgrading my battery so I thought I might as well upgrade the controller while I'm at it. I've seen posts on here about people upgrading their 48V 1000W kits to a 72V controller without issues. I've found a few 72V 1500W controllers on ebay and various chinese sites. But if anyone could suggest a better controller, be my guest.

A few questions:

1) Can I use my old lcd display with the new controller? I don't see the right wire connectors in the pictures, so I'm guessing the answer is no. But my lcd is used to turn the controller on and off, so I don't see how one could be used without it.

2) Should I go with these turnigy batteries? (http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html) I'll use them in 3S 2P (75.6V 10Ah) for now, with the option to add more later. If anyone can suggest some batteries that are basically the same thing but cheaper, or another site that sells them for less, please send that info my way.

Attached is a pic of the bike I will be upgrading. Thanks!

 

[wesnewell]

1) I've never seen a 72V controller with a control display, so I doubt it unless you can rig it up yourself.
2) If you buy from HK, buy from their US west coast warehouse, not the international one. Shipping from china will kill you. The 4s hardcase packs are cheaper, but you'd have to go to 20s (74V/84V) and I don't know if you thought about how you would charge them in either case.
The problem with going to 72V is that the potential will be there to over heat the motor if you run wot to long, but as long as you cruise under 35mph, that shouldn't ever happen.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html

 

[dogman dan]

Best thing you can do, is get your hot controller with a Cycleanalyst DP plug. (grin, em3ev) Then you can run the best display for ebikes on the planet.

Full race type riding that motor at 72v 40 amps will definitely overheat it, generally in about 10-15 miles. But with a CA you can limit amps, and have a very perky ride with 30 amps, that won't likely fry the motor.

Personally, I like the ride better at 48v 50 amps. Still a very perky ride, but speed a more reasonable 32 mph or so. 72v just makes the throttle very sensitive, and hard to ride slower when you need to.

Best thing you can do is get a controller that does 36-72v, and then have lots of flexibility for different battery voltage. find what suits you really well. You can look more legal with a lower voltage, but still have a bike that can wheelie.

Also, that bike will be very squirrely to ride at 40 mph. Much better to have a tank slapper at 30 mph than 40. You need a much stiffer frame from side to side for 40 mph. That's a bike shaped object, as we say here.

So another reason to not go to 72v right away. Get the controller and run 48 or less for now.

 

[Baron]

1) I've never seen a 72V controller with a control display, so I doubt it unless you can rig it up yourself.
2) If you buy from HK, buy from their US west coast warehouse, not the international one. Shipping from china will kill you. The 4s hardcase packs are cheaper, but you'd have to go to 20s (74V/84V) and I don't know if you thought about how you would charge them in either case.
The problem with going to 72V is that the potential will be there to over heat the motor if you run wot to long, but as long as you cruise under 35mph, that shouldn't ever happen.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html

Thanks for the tip on the lipos, those look great. More power, less weight, and less price than what I was looking at before. For now, I plan on using my Imax b6 charger which should charge and balance the lipos nicely.

Best thing you can do, is get your hot controller with a Cycleanalyst DP plug. (grin, em3ev) Then you can run the best display for ebikes on the planet.

Full race type riding that motor at 72v 40 amps will definitely overheat it, generally in about 10-15 miles. But with a CA you can limit amps, and have a very perky ride with 30 amps, that won't likely fry the motor.

I'll definitely be getting a controller compatible with a CA (which will be another future upgrade). But I don't really know where to look. Ideally it would have the variable voltage settings you mentioned, with 30/40A max current. Any ideas?

So if I don't go full throttle for more than 10 miles straight and I let the motor cool down regularly, there should be no problem? Also, avoid going full throttle up long hills? That's not my riding style anyway. I usually go easy on the throttle to extend battery life. Rarely go full throttle up hills, never use the throttle downhill. I think I could manage 72V, but it will definitely take some getting used to.

Btw, since that picture was taken, I've upgraded my freewheel to 11t - 28t, slick tires, got a metal box for my batteries, and a better battery bag on the rack. When I get my new batteries I'll try to mount them in the middle/bottom area of the bike for better weight distribution. The bike might look like a buster but it has a steel frame and a torque arm on the dropout. Could definitely use a paint job though!

 

[wesnewell]

You'll get tired of charging with the B6 charger quick because it will take ~15 hours to charge a 10ah 20s pack with it not to mention all the hassle. I'd suggest a bms with charger so you could charge it without hassle in a short period of time by just plugging the whole pack in at once.
Here's the controller I'd get to run 20s.
http://www.aliexpress.com/store/product/Free-shipping-72V-1500W-45Amax-BLDC-motor-speed-controller-15FET-4410-s-Electric-Bicycle-Controller/313864_499889986.html
Have lvc set to 70V. and any other customize you want. They may wire up a CA direct plug for you, but I don't know. I've never found a need for a watt meter. Had one, and took it off. A simple voltmeter is all one needs.
http://www.ebay.com/itm/DC-15-to-120V-Waterproof-Red-LED-Panel-Meter-DC-Digital-Voltmeter-Two-wire-NIGH/141365876290
And I wouldn't run it more than needed at wot. But you should be able to cruise 35mph or less forever. Beef up the battery wiring and connectors.

 

[Drunkskunk]

I'm guessing you're getting around 27mph right now? The jump to 75 volts will put you around 37mph.
Depending on how extreme you want to mod things, an Infineon based controller would be the best option. check EM3ev.com for a CA compatible controller.

Your motor is good for 2000 watts peak as it is. 3000 can be had if you want to modify it. So if your goal is 75v at 40A, you'll need to look into beefing up the phase wires and adding some form of cooling.

There is no way that bike should be rode at 37mph for any length of time, except on a closed track with paramedics on hand. Before you do the other upgrades, start with upgrading to a bike that can take the added punishment that high power and speed brings. A good bike can be found on craigslist for cheap, and will give you a much better platform for building what is essentially a motorcycle. At 3000 watts, you will have the same power as a 80-100CC 4 stroke motorcycle.

 

[wesnewell]

I've been using the same $99 bike for close to 3 years and over 10K miles now at speeds up to 61.4mph. I'm 270lbs, I did replace the BB bearing after a year,, and used my own wheels and tires, and replaced the brake pads with bigger ones, but the frame is stock. Sick of hearing this BS about cheap bikes. BSO, and other crap. It's just elitest BS.

 

[Baron]

Here's the controller I'd get to run 20s.
http://www.aliexpress.com/store/product/Free-shipping-72V-1500W-45Amax-BLDC-motor-speed-controller-15FET-4410-s-Electric-Bicycle-Controller/313864_499889986.html

(before you order or pay, please confirm the max current you need, and tell us the functions you prefer, we will make the controller as your request in 3 working days, please be patient, thank you!!!)

So I can ask them to set the max current to 30A, and the voltage cutoff to 70V? That would be perfect.

Alternatively, I could go with an infineon controller: http://em3ev.com/store/index.php?route=product/product&path=38&product_id=80
Usb programmable, compatible with CA (future upgrade), 30A max. Looks right?

I don't ride on roads with heavy traffic...30mph is comfortable, 35mph only feels right on a flat road with little traffic. I've bombed down hills at 40mph on this bike and it in no way feels safe. So 35mph top speed is the sweet spot, think i can achieve that with ~80V 30A?

I have some more 10 gauge copper speaker wire that I can put to good use. A good bms and charger will be future upgrades. I also want to mention, I'm trying to build the bike to be as stealthy as possible. i.e. not to turn a lot of heads when riding on a sidewalk without the motor, for example. So I'll probably need a new bike with a triangle frame to hide the components better. Oh, and disc brakes.