Wilderness Energy BD36 running at 48v
I wanted to post my experience with my WE BD36 here as I came here about a little over a year ago and many helpful people answered my questions.
First off, I've now commuted just under 1300 miles on my bicycle. My bike is a hybrid in that it is a 1986 10-speed complete with rams-horn handle bars with a 27" wheel on the back and the 26" BD36 wheel on the front. I ended up replacing the front forks with MTB forks which allowed me to put MTB brakes on the bike. I had previously created an extension to allow the original caliper brakes on the 27" fork to reach the 26" rim.
Originally I wasn't satisifed with the speed of the bike. At 36 volts, it's top speed was 25 mph, and it allowed me to average 18 mph for my
6.5 mile commute. After getting the motor specs from WE and leaving some questions here, I decided to add another battery and try 48 volts. After proving that it would work, it ended up being a major upgrade.
The stock bag wouldn't hold 4 batteries and the stock rack was flexing with the three I already had, so I ended up replacing it with a heavy-duty rack. And of course I had to buy a 48 volt charger. The Full and Low charge indicators are now mostly useless. In order for Low to accurately reflect a Low condition for a 48V pack, I would have to characterize the Low voltage drop with a 36V pack and then add a resistor into the circuit. But I have enough juice for my commute to run full throttle all the way. In short, using 48V with a controller designed for 36V I always read Full.
I initially purchased a trunk bag with panniers which unzipped from the sides and put two batteries in each side. This didn't work too well because 40lbs of battery was too much for the bags internal structure and it gradualy began to collapse. In addition, the weight was still carried so high as to make the bike very unstable if I stopped at a light and leaned a bit too much. I ended up getting a dedicated pannier set that brought the batteries (loaded side by side vertically) almost down to the axle. Ideally I'd like it to be even lower, but this is okay. I used closed cell foam from a computer monitor to line the panniers to keep the battery corners from digging into the bag. The trunk bag sits on top to carry my stuff -- it's panniers I use for clothing when it's cold in the morning but warm at the end of the day.
The happy surprise is that I'm still using the WE stock controller with 48 volts. I decided to give it a go when I saw another 48 volt e-bike somewhere with a controller which appeared identical right down to the harness. Others here had recommended I replace the internal capacitors. But I can do that when the time comes.
Regardless, I now typically average 26 mph with a top speed of 32. Although I have had an instance where I was peddling very hard heading down hill with a tail wind and hit 36, I generally try to keep it around 30 figuring Lance Armstrong can pedal that fast without assistance and he's safe in just a bicycle helmet.
The only other change I made is related to the throttle. I was dissatisfied with the spring-loaded thumb throttle because it wouldn't slide along the curves of the 10-speed bars. I ended up making a bracket for it that put it next to the stem, but that required me to stay upright. I ended up putting a friction lock on it so it would stay where I set it. Using a multimeter I figured out the wiring and added a slider rheostat like what you'd see on an old graphic equalizer. This I located on the inside of the left drop so that my left thumb could work it. So now when I get going in the morning, I set the throttle on max and my thumb lever on min. The only thing missing and is currently in work is to add some sort of switch which opens the throttle circuit when I engage the brakes. I had a couple of instances where I needed to switch to brakes faster than I could work the throttle.
Lastly, I replaced the RCA-type connectors used for the charger with a heavier duty shielded connector readily available from an auto-parts store. I'd been having contact issues during charging and had replaced the female connector a couple of times. With my pannier arrangement I also had a couple of instances where the RCA charging connector bounced and momentarily hit a battery lug. It kinda arc-welded itself. Finally, the male connector on the charger somehow shorted out internally right before I plugged in the charger. The resulting brief fire melted a portion of my wiring harness. It was a pretty blue flame though. :-)
One final observation. Because of the magnetic pulse nature of the motor, my experience is that pedaling helps primarily with range more so than speed. I found that pedaling as hard as I could I just couldn't go significantly faster than the wheel wanted to turn itself. The magnetic pulses are synchronized and pedaling hard would seem to eventually try to move the wheel out of sync -- I felt resistance. In fact, the time I hit 36 mph, I was initially at full throttle and then I turned it off part way down the hill. Then I could pedal as hard as I wanted with the front wheel just free-wheeling. In short, if the theoretical maximum speed is what the wheel turns at full throttle when you are stationary and lift the wheel off the ground, your pedaling overcomes your own plus the bike's mass to reach that speed, but no faster. But the extent to which the wheel itself must draw on the battery to reach that speed (if you don't pedal as hard) obviously effects battery life (range). It would be interesting to see if the down-hill (or manual) braking effect could somehow be used for battery recharging.
Anyway, I hope this helps someone. Comments welcome.
Thanks for that.
It was informative. I am about to go to 72 volts on a wilderness energy motor with a new controller. Waiting for it to arrive in the mail.
They should also carry the brushless version. Apparently these motors can handle 72 volts. I'm putting two 36 volt Dewalt packs in series, three times with a switch to move between series connected packs.
I also own Dewalt power tools so half of the batteries came with the tools. A thousand bucks for many years of bicycling and 45 minute charges is well worth it to me. The price will come down some day and even at this price they will pay for themselves many times over with saved gas and car maintenance. Look at it this way, they cost about the same as a few car payments.
Don't know the answer to your questions yet but I have been using four of these batteries at 36 volts for just less than a year now and they give me far more range than the 8 amp hour lead acid batteries I started out with. I think that is due to the decreased weight and the very flat voltage discharge curves. These batteries stay lively right until the very end when they suddenly poop out. I also sometimes charge them up two or three times a day when I am doing a lot of riding.
By adding two more I will keep the great range but also have the option to go faster when I need to, start from a dead stop and accelerate quickly through dangerous intersections. I may get much more range than before if I don't ride any faster and don't need to accelerate from a dead stop often, as on a long ride on a bike trail.
The lead acid would just get slower and slower as it discharged and deep discharges limited the lead acid life. Not to mention it would take 4-6 hours to recharge them instead of 30-60 minutes.
I want to be able to charge them a pair at a time. I don't want to have to put all six on chargers at once. If I discharge all six and then only charge two, I can't put them back in parallel with the other four without diodes in the lines to keep them from back charging. I have four chargers at home and take two with me in a backpack on long trips.
I have talked to guys who have had a cell drop dead and I think it was because they allowed them to get below 2.5 volts. These batteries fall off very rapidly at the end of their charge and if one battery is not well matched it will drop off before the others and go flat. This chart shows you what I mean:
The batteries can take ungodly discharge rates (70 amps continuous, 120 amps for ten seconds).
Well, this is interesting. Why does Wilderness Energy advertise it as 36v when it can support 48?
Yeah - those are good points. And ones I make myself at times.
Bicycles generally aren't build for high speed and in California a vehicle with between 20-30 miles/hr speed capability is classified as a moped. But some people I've had this conversation with get rather huffy -- they point out many bicyclists can, unpowered, get to speeds well above 30 miles/hr. Makes you wonder why the rules are set as they are.
That thing is RATED to 96 volts!? RATED? :jawdrop: Are you sure? That's insane! That's over 60mph in a 26" rim! What the hell?
Well, if you halved the amp-hourage, you could get the same wieght. Or, better yet, use lithium. Since I'll be carrying my batts on my back, I don't think 80lbs of lead would be a good idea.
But, seriously, 96V? Cause I might just be crazy enough to try it. In fact, it may be an inevitability...
You could just make a special charging connector out of Molexes to use a 48V charger, BTW. Or use a big fat high amperage 12V charger to keep them balanced.
I don't think it would quite cut your range in half. You'd just get crazy top speed. You'd probably see a drop in range at the same speed you were going at 48V, but not that bad. Just speculation, anyway.
I can't afford lithium packs, either :(. However, the DeWalts are top of the line. You can get decent packs from Ping on eBay. The jury's still out on their quality, but I gather that Ping is a pretty good seller from one of the Endless Sphere threads. The current bid for a 48V 20Ah pack is about $500. That includes a BMS, charger, and shipping.
I have no idea what that federal mileage thing is.
Yeah, the weight is pretty high. But it doesn't have anywhere else to go. I'm planning on using a BMX. My MTB is full suspension, so there is absolutely no room for the batts in the frame. I don't think it will be that bad, though, because I've been riding with a heavy backpack for years. It just takes getting used to. This one's just a little heavier.
I put a bit of thought into the battery connector issue. I think it was the first problem I thought of. My solution was a little complex, but workable:
The connectors would be just plastic things that had metal plates on them. The plates would have big connectors for power, and smaller ones for throttle. They'd be held together by neodymium magnets. There would be a spring loaded sliding piece of plastic that covered the contactors as soon as they were separated to prevent shorts.
That's my ideal solution. In reality, I'll probably just use powerpoles and a Molex. Fuses and breakers will be used, of course. Hopefully, the contactors or wire will snap if I fall, but just give me a tug if I try to walk off. I'll carry a small repair kit in the backpack, too.
Yes, falling would be so weaksauce. Not much you can do about that.
As for the lithium fires, that problem was solved a long time ago. The problem was that the packs that caught fire were chemically similar to an explosive. In other words, they contained both a fuel and an oxidant. LiFePO doesn't have this problem. But shorts still suck, especially with A123s.
As for arc welding myself to the seat, well, I just hope someone has a camera handy ;).
Thank you for posting about going from 36 to 48 Volts. I didn't want to destroy my controller and your post helped me make up my mind to give 48V a try with the existing controller and motor. Now that my Wilderness brushed 36V motor is running at 48V, I get get the kind of speed that I wanted. The four 10A/Hr SLA batteries weigh a ton and my bike is getting beat up but it's sure a lot more fun at 25MPH than 18MPH.
I was wondering if you still have a 48 tooth crank sprocket. I added 12 volts to my 36 wilderness Kit and found that I had so much speed that I could not peddle, so I found a 60 tooth crank sprocket, now I can assist up to 30 to 35 MPH. I have the website where I got the sprocket. http://www.gaerlan.com/
I bought my BD36 motor kit off ebay about three months ago...I installed it on a Schwinn s-30 Full suspension MTB. I thought i was amazed with the stock kit. Made and extra battery pack and everything. I considered going to 48V with stock controller. I got mad when non of my local shops didnt carry a rack bag big enough... Today i decided to tackle it again. I realized that there was a plastic shell in my bag ... i removed it and it gave me the clearance i needed to shove the 4th 12ah SLA in my bag. Compared to the 36v pack i notice the speed and torque increase... The hills in my complex that i used to have to use the motor to assist me im able to get 80% up these steep grade hills before having to pedal. One thing i do notice... You can feel the hub motor heating up.... smell it a little bit too. I plan to move closer to my job to where im like 2 miles away from it and gas isnt hurting me that much but it will definetly raise an eyebrow or two. Ive been wanting to get a 48v 20 ah kit if this was successful... Thinking about selling the bike and making an illegal trike...lol How much u think this would go for... Im currently charing my pack by using a low amperage car charger and wiring them all in parallel... any placve i can get hold of a 48v charger. How far do you think i can push the stock controller.... What about range.... i didnt test it but under my assumption the more voltage you have the less amperage it needs therfore increased range.... but im not sure how the controller is wired. I know there are sum the more you give it the more amperage it pulls... Note to all... Slicks wet pavement and speed on an overloaded bike in a corner.... not a good idea...
Voltage translates into power (48v faster than 36v). AH translates into range (12ah further than 7ah).
Not really, but close.
Voltage = RPM
Current = Power
Amp Hours = Range
Adding Voltage at the same Amp Hours also adds Range provided your max Current draw is the same as before you added the Voltage. Range is a function of Watt Hours which is Voltage times Amp Hours.
Here is a simple chart with formulas showing their interdependencies.
You can replace watts with watt hours as long as you replace amps with amp hours in these formulas.
Grandpa Chas S.
So if the stock controller was a 20A 36V controller.. more likely its pulling 20A at 48V?
I would guess it is pulling more current, about 25 amps would be my first guess. This all has to do with voltage, current and resistance. We know the resistance stays about the same because we did not change the motor, so we can calculate the resistance using E / I = R, or 36-volts / 20 amps = 1.8K ohms. Now that we know the resistance we can calculate the new current draw, at the new voltage, using E / R = I, or 48-volts / 1.8 = 26.6666666667 Amps. You have to use all the pieces to get the correct answer and this is still only theory. I would want to use a meter to measure these values. Remember there is voltage sag from the batteries which in turn causes current sag and the RPM of the motor causes its' resistance to change over time so this will also effect voltage and current values. As you can see the formulas are great for getting an estimate of what you should see, but it is no substitute for a good old meter.
Grandpa Chas S.
GRRR volt meter going spastic... needs new battery.. Im checking resistance across the motor right???... I agree with your theory unless the controller had a fixed voltage regulator but if the motor is heating up and its faster then its prob pulling more amps... thanks for the info.. I just looked at the guy that made the onride video thats wicked speed... I wouldnt mind registering my bike with the dmv .... Strongly considering building a trike. Cost is almost not an option cause i know im going to use it everyday and it will pay for its self. Do you think i can get even halfway to what he is doing by going to 72v and a new controller.... and slas.... i dont think lithium can take that much current draw... nimh is not an option at the momment without a trailer.
By some miracle I shoved another battery in this bag for rear rack. So now i have 5 12v 12AH SLA. Its running at 63-64 v charged. I think running this high this would be a pedal start and then possibly using the controller. Someone mention using the cheap plastic chinese controller they melted one of the traces on a long hill. I have the bike upside down free spinning and its going fast and doest have that annoying hum. The controller is cool. The motor is barely warm. I did a 2 minute dead stall with the breaks applied to test worst case senario trying to get it to pull the mamximum amps... nothing spectacular happened. Its 1 in the morning i cant test ride it...... Will let u know whats what when i test ride it on some hills in my apt complex. Going to get a new controller might as well try to push the old one. 60V might be the satisfaction i need.
So if the stock controller was a 20A 36V controller.. more likely its pulling 20A at 48V?
Yes. Since the controller measures the voltage differential across the shunt (which is proportionate to the current being drawn), it is unaffected by voltage.
Oh, yeah: Remember to check the brushes a little while from now. Higher voltage causes them to wear more quickly.
I just did my 60V test with stock controller. Results were good. I drained the pack entirely with any smoke testing. The controller didnt get warm. The hub motor thats another story. Definetly warmer than my 48v test.Its warm to the point after 10-15 seconds you might wanna move your hand... It was pretty cool this morning only 55 degrees. The speed was excellent. Torque was excellent. Climed all the hills in my complex with out stalling or need for pedaling. I think because of the combination of speed... inertia and additional torque. The speed of my bike is exceed making it very unsave to pedal not unsafe to justify the cost of buying another ring gear.. I did dead starts and peadal first starts no problem... If im not carful on a dead start i might have a seat where the sun dont shine.Im 6'1 280lbs.. Fit in endurance but not in shape. I do 20 miles without the kit sadly 20 with the kit. with 50lbs of slas a 37lb bike and the 10-15lb weight of this hub motor. Im doing damn good. Gotta get a speedo... Lost my last one but on flat ground. Acceleration and speed.. Easily a daily commuter no effore required. As far as durability... Like i said im fluffy Im maxing out the system at 60 v this thing should be fried... how many more runs its gonna take i dont know but it has my two thumbs up... wonder do i have to register this yet lol.... lets add one more battery! and find out.Sure do wish i had a 60v charger im tired of rewiring this pack to charge. with my 12v charger I think i might do a 48v to 60v mod an ad a toggle switch to switch between the two voltages ... Like a flat level at 48v and a speed/hill climber mode. I got how to do it in mind any tips on executing it.