Alternative controllers for BD36 - more amps.
Has anyone tried other than stock controllers for a BD36? I went up to 48v hoping for more torque in addition to more speed and range, but didn't really get more torque. The more I read, it seems that (paraphrased from Wikipedia) voltage is proportionally related to motor rotation speed, and current (amps) is proportionally related to torque. My question is: has anyone tried a controller with greater current capacity (more amps) and gotten more torque?
I will eventually although not at increased voltage;
My BD36 was DOA and I can't find a replacement from ANY vendor so I ordered an ecrazyman 36V-40amp. That is a 5 amp increase but since I never got to use the WE factory unit, I won't have anything to compare it with. 3 months I've been trying to get this project on the road and now summer is over :( Man I wish I could do this over with another product!
Ecrazyman on Ebay is the guy to get hot controllers from. Some folks with the brushed motors have just wired the motor to the battery with an on off switch. It can be hard on the batteries and definitely hard on the switch, but you could try that to see what max is like if you have the BD. 50 amp house breaker is the most likely switch to survive this. A doorbell button would be ideal if it survived, but most likely it would melt in seconds. or worse, weld into the on position.
There are a lot of variations in the description of the WE products such as this one:
Dennis @ Bernson told me WE has only used the 20amp for 2 years yet my kit said 35amp so, what to believe? I'll be watching these posts to see how others do with their WE parts. Me, I'm disgusted with the WE QC and corporate 'brush-off' and I regret my purchase decisision but won't give up on the general idea. Maybe we should have a rant topic!
Second the e-crazyman notion. He's got the good stuff. And easily moddable if he doesn't.
And I'd say the limit on the BD-36 is 50A. I've seen them sold in sets with controllers that big before. But going higher is probably not a good idea; icecube over on the ES fried his with a 100A controller, which is definitely overkill.
I run 72V and 30A on mine, though I don't recommend the 72V part. Wears out the commutator plate, which can't be replaced.
I'm pretty sure older bd36 kits had a 20 amp controller, but the new ones, mostly sold this year had 35 amp controllers. Few folks rewrote the ad copy though, and some may have even had old stock. They didn't sell all that fast till this spring.
Rule 1 never believe any claims in ev ads. Especially range and power. A lot of em have bad translation, or never get updated. for example,
If my controller is 35 amps and 36 volts the peak wattage is 1260 watts. But they call it a 600 watt motor. With the old 20 amp controller wattage is 720 at peak, so since that is cut off time, call it 600 watts. But change the controller, adding speed, using more watts, but don't change the range claims. Oh no! The forums have the real truth, as I have tried to post about anything I actually have done. Some things are still a mystery, such as the true amps of a WE BD36 controller. But the performance of my bike makes me belive I don't have a 20 amp in my bike. It has to be at least a thirty.
At rest the controller is using very little watts. One rule of thumb I've gleaned from others is that on flat ground, going less than 20 mph, few bikes draw more than 12-15 amps on a 36 v battery. Guys with a cycleanalyst can learn to ride so that is even lower. I just go flat out till the battery dies.
Nice post dogman! I like the feedback on these forums. Like you said; sure beats the vendor's claims.
Aside: I ordered a BD36 controller 'old style with a key' from BersonEV. He must have had the last spare in the USA and really has no way to know what amps it is but just maybe I'll get to drive down the road 90 days after I started this venture.. Who knows when I'll see my ecrazyman unit but when I do, Ill have to experiment. I do have a CA to tell me what's happening. The motor is the only seemingly functional piece of the kit and I hope to get what, 5-600 miles out of it if I'm lucky? I see on ebay there is a Golden 36V brushless listed under 'hub motor'. I was so tempted but collecting parts for fun could get serious real quick.
I see on ebay there is a Golden 36V brushless listed under 'hub motor'. I was so tempted but collecting parts for fun could get serious real quick.
Hey! Back! Back, I say! I've already got my eye on it. :P
And you'll probably end up fairly serious, anyway. Ebiking's an addiction. That Golden will bump me up to three hubs. *puff puff*
You'll get more than 500 miles out of your hub. I had one die at 400mi because I rode with it too hot to touch every day for one hour nonstop at full throttle. That hub died in 100-105 f weather, and humidity also contributed. In june in NM humidity can be below 5% for a full month. The result is , air cooling doesn't work anymore. Actually it's the water molecules in the air that do the cooling. All us desert dogs know to carry a squirt bottle to cool down bikes and VW's in June. My other motor, which has almost 1000 miles on it now is perfect inside, I looked. It was only ridden in the 95 F weather of spring, and recently I was riding 20 minuites to a bus ride in the afternoons. From other owners feedback, even brushes should last 3000 miles, and if you don't ride like me, the hub will some decade need bearings. I don't blame you for being miffed at WE. They should have held some kits back to provide warranty parts. It's not like they didn't know the situation with bad stuff in the kits. Or even, imagine that, testing stuff before they send it out!
Parts collecting can be a disease. I'm buying a garage sale bike nearly every weekend. Soo hard to not buy one that has no parts I need on it. Some are just interesting. Yesterday at goodwill I saw a mongoose MTB so vintage it had 27 inch wheels. About 300 bucks worth of components on it for 10. It had the smallest front crank I ever saw on it.
Link (or anyone else who knows the story),
What exactly did 100A do to icecube's motor?
Hmm, lets see...melted brush holder...warped commutator plated...charred windings...the works, pretty much. Burned his fingerprints off, too. I don't think he ever did manage to get it working again.
Also, is it primarily the greater amperage that makes the Phoenix gain speed more quickly than other bikes? Youtube videos of those things are awesome! Would more amps with a BD36 make torque arms necessary? I'm guessing we'll need to test these things.
More or less. The "Phoenix" line (5-series/X5) motors are much bigger than the BD-36, though. About double the weight. And they're brushless, meaning there's no brushes to screw up.
Torque arms are a good idea period, especially if you have aluminum dropouts.
Although I don't have BD36, this is my plan to up the amps on my ride.
I have an electric scooter with a Unite MY1020 24v 500W motor and 750w controller from TNC.
The controller limits the current to the load to 30amps max. This causes stalling when going up a steep hill.
I added 2 10 Awg output wires from my controller, one wired directly to the (-) supply from the battery, and one to the (-) supplied to the motor.
I will add a heavy duty relay between these wires, when closed it will actually bypass the controller, and will supply unlimited current to the motor.
The relay will be controlled by a "Turbo" or "Nitro" (TM) button on the handle bar.
When going up hill I will push the button to get extra torque from the motor. But I will be carefull not to use it too often, of for to long to avoid overheating and damaging the motor.
That will work good for getting up the hill. However the c rate of your battery can easily be exceeded, particularly if the hill stalls the motor, so battery damage can happen. The point of the controller, is to controll the drain on the battery so this can't happen, as well as providing speed variation. Depending on how you use it, it could be ok, or cause serious wear on the batts.
I wouldn't do that if I were you.
The reason I'm doing it with a separate button, and not by using a higher amp controller is that you cannot really know how many amps you're drawing from the battery at any given time.
I tend to go full throttle most of the time, and if the amps to the motor are not limited to 30, then I think that the motor will pull over 30 amps for even a small grade hill, even though I could've got up the hill with less than 30 amps but slower.
The button will be used only when the the motor would've stalled with the limit on, for very short bursts.
I wonder if icecube went full throttle for a long period to fry his motor with 100A, or if it happened quickly.
It was for normal riding, so a fair bit of time. Plus he was at 60V in a 26" rim, which equates to too much speed for a BD-36 to handle.
Still, a dead short supply to the batteries is hard on the motor and batts. It should be fine for short bursts, but don't use it often, and using it from a stop probably isn't a good idea.
Everything you want to know on how to kill a BD36 and a brushed Clyte 409
48v and 35A is as high as i would go on 26" setup. Get a lithium pack also. You can go quite a ways with a 10AH Lithum pack vs a 12Hr SLA. SLA setups ur lucky to get 60 to 65% of their rated capacity when lithium get about 90% if not more. The power curve is stiffer with lithium batteries vs SLA because you speed is in direct relation to your voltage. SLA sags like a MOFO especially at higher A thats a downside of getting a higher amp controller. Lithiums provide a steady output without much sag but cheaper lithium setups have crappy bms that might not be able to sustain 40-50A for long periods only in short bursts but 48v would give you respectable mid 20s speed. Not significant gain in torque though. Longer periods of open throttle can cause the controller to pull slightly higher amps over an extended period. This can be proven with three stalls of a motor which each stall pulls more amps than the last. Although 36v-50A should be alright if ur a torque junkie. It will help you sustain top speed better through various terrain. You can find controllers at TNC scooters Or mod the BD36 controller and add solder to the shunts to increase amp limit without buying new controller. So on a stock controller if its a 20A modifying the shunts should double the current and should be good up to 48v and its a 10 minute job to perform the mod. If its a 30-35A I prob wouldnt mod the shunts and take it to 48v as is. Comment on TNC Scooters. DO NOT GET THE 40-100A one. And 75% of 36v controllers should be good to 48v
Actually cheaper lithium, duct tape Lifepo4's, come with a bms that exactly matches the cells capability. Doesn't stop people from buying 10ah batteries that can't handle the amps their bikes pull, and then being pissed at the performance of the battery. If the stock bd36 controller with a 48v battery is too weak for you, you have the wrong motor. Get a big ol chrystalite and then sell the bd to get some money back out of it.
the nice thing about ping packs is although you can use the bms for charging and discharging. Its so easy to bypass but yet keep it intact that its almost pointless. I look at it this way a pack is rated for x amount of cycles at x amount of current. anymore you reduce the cycles and possibly the safety but it doesnt mean its not capeable of it. You just have to make sure you dont over discharge. If you use it in conjunction with a cycle analyst and program the lvc on it to throttle back before it reaches the lvc of the batteries and the cells you should be fine. The motor he using can be salvage for higher performance he just has to understand the concepts on doing it. I got several approches from using the motor like a stoke monkey for superb torque with gearing to just putting it in a smaller wheel and overvolting the hell out of it.
80% of those tests were done on the BD36 motor I didnt switch to the clyte until the end. When there was no more ressurecting my old bd36 motor. The only reasonable controller i see are on ebay. They are 30-50 bucks after shipping. The highes i see 50A Amps for a brushed ebike. But can be easily bumped up to 50-60 if u got soldering skills. As i say again it only takes a few minutes. But if you dont have meters and stuff you cant tell how much you boosted it.
48v and 50A
As much as i like power... Go with the 33A its suiting me just fine.... I modded the fets and the caps so i can play around with voltages. I currently use it at 36v 33A for exercise on trails by where i stay. It move a 280lb rider a 45lb bike and 30lbs of sla without a problem. Take off isnt stellar but its enough amps to maintain top speed and get me through rolling hills... while staying in the low 20mpg range