Fixed vs Variable Voltage Controllers

[jimw1960]

I upgrading my Crystalyte 408 motor from 36v to a 48v system. My Ping v2.5 should be arriving in a couple of weeks. In the meantime, I need to buy a new 48v controller to get ready for the upgrade. With so many choices available, I am perplexed as to what would be best for me. Variable voltage controllers seem to offer good flexibility, but the Electricrider.com website's FAQ section offers the following opinion"

"Variable Voltage Controller: We tested every one of them, and every one of them failed. Performance and reliability both suffer so much we will not off a variable voltage controller."

I have not read any such experiences on this website. Is this just BS so they can sell more of their fixed-voltage controllers?

The other thing I'm wondering is if there is any advantage to using the 48v/40A controller that is designed for the 530x series motors, instead of the 25A controller they offer for the 40x series. Is 40 amps overkill for a 408? In other words, would a 408 ever draw more than the 25A that the standard controller provides, or would that be a rare occasion that does not justify the extra $$ for a bigger controller?

Another question I have is if the pedal-firs sensorless controllers are as efficient as the no-pedal controllers. I've heard folks say they are more reliable, but it seems making use of the Hall sensors would give optimum efficiency. I really like having throttle from the get-go when I'm at a red light with cars behind me, but increased reliability could pursuade me to go sensorless if there is no loss of efficiency.

Thanks in advance for any advice. I learn so much here.

 

[fifthmass]

I upgrading my Crystalyte 408 motor from 36v to a 48v system. My Ping v2.5 should be arriving in a couple of weeks. In the meantime, I need to buy a new 48v controller to get ready for the upgrade. With so many choices available, I am perplexed as to what would be best for me. Variable voltage controllers seem to offer good flexibility, but the Electricrider.com website's FAQ section offers the following opinion"

"Variable Voltage Controller: We tested every one of them, and every one of them failed. Performance and reliability both suffer so much we will not off a variable voltage controller."

I have not read any such experiences on this website. Is this just BS so they can sell more of their fixed-voltage controllers?

The other thing I'm wondering is if there is any advantage to using the 48v/40A controller that is designed for the 530x series motors, instead of the 25A controller they offer for the 40x series. Is 40 amps overkill for a 408? In other words, would a 408 ever draw more than the 25A that the standard controller provides, or would that be a rare occasion that does not justify the extra $$ for a bigger controller?

Another question I have is if the pedal-firs sensorless controllers are as efficient as the no-pedal controllers. I've heard folks say they are more reliable, but it seems making use of the Hall sensors would give optimum efficiency. I really like having throttle from the get-go when I'm at a red light with cars behind me, but increased reliability could pursuade me to go sensorless if there is no loss of efficiency.

Thanks in advance for any advice. I learn so much here.

I got the Electric Rider Roadrunner kit last November. It's the 48 volt version with the 408 motor. I got the 40amp Pheonix (530x series) controller instead of the 25amp that comes with the kit. I don't regret it. Under normal conditions you will very rarely pull over 25 amps but I have pulled 38 amps with my 408 under heavy acceleration from low speed; I probably was actually at the 40amp cutoff, so yes, the 408 can suck power like you read about. On a couple of occasions that extra acceleration/amperage has saved me from accidents. The only caveat with going with a 40amp controller on a 408 is that you should get a CA or a WattsUp meter to monitor your current demand and try to keep the battery drain at 1C or less. If you're getting the Ping 20ah you should be fine and will get insane range if you pedal along with the motor.

The 40 amp unit will run cooler than the 25 amp unit with that motor; better for longevity. The 40 amp controller will likely NOT fit in your bag with the battery. I u-bolted mine to the seat post so it's in the open air. It has never felt warm to the touch mounted in the open air.

Unless you weigh as much as a ferret you won't get major acceleration from a stop with a 408 even with 48 volts.

The multi-voltage controllers sold by Justin at ebikes.ca are excellent and they come ready to plug in a Cycle Analyst too. Don't listen to Electric Rider on that one.

I can't answer your question regarding the efficiency of the sensorless controller, they are simpler than sensored units but that's all I know.

Regards,
Bill

 

[Ypedal]

I find that the instant start controllers are smoother than the Pedal First units, so i suggest it for that reason.

The 408 will take the power, no worries about cooking the motor unless you reallllly try hard.. but to save some space the 25amp controller will do the trick imo.. the 40 amp unit is just more money, more weight and more bulk that you won't use to much advantage on a 408.

Don't mount either controller inside a bag, frame mount with flowing air is a must for long controller life ! :wink:

Don't bother getting a 72v controller if you plan to run at 48v, no advantage in that either. the 36v controllers work just fine at 48v ( except the 29v lvc value !! )

 

[dogman dan]

I tend to agree with both choices, each for good reasons. 40 amps is nice to have when you need it. I have a 20 amp, and running at 36v, I rely on not being in situations that require 40 amps. Drivers here suck, but really, its still a pretty small city. I do very little riding on a fast street where I need to dodge cars, and might stick to motorcycles if I had to ride such streets. The ping will be very happy on a 20 amp controller, and if less than 20 ah, size, you need the smaller controller.

I like my aotema controller with no halls. It's not really pedal first, it will start from a dead stop, and only needs a little bit of forward roll to start smooth enough. High tech bikes for one, they do 48v fine in most cases.

 

[jimw1960]

Thanks for the info and advice. I'm getting Ping's newer v2.5 battery, which is supposed to handle 2C, so a 48v20ah should be able to handle short bursts at 40 amps just fine. My commute to work is 14.5 miles and the first and the last half-miles are on busy streets with no shoulder where the extra Amps could keep me out of trouble. The rest of the trip is pretty tame.

My 36v/15ah jimmywu battery just gets me through the round trip if I peddle on the hills, I agree I should get insane miles on a 48/20 Ping.

I'll probably cheap out and get the 4825 controller just because it's $100 cheaper.

 

[tostino]

Keep in mind the infinion controllers available... I have heard of great reliability from them, and they are extremely affordable!

You just have to get in contact with Keywin to get one:
ecrazyman@gmail.com

 

[jimw1960]

I see the infinion 48v/30a controllors on ebay are about $40 cheaper than the 48/25 controllers from Electric Rider, but then I have to deal with rewiring connectors for compatibility issues and I'm not sure about quality with the infineon brand. I'll see what I can find out. Thanks for the tip.

 

[tostino]

Well even on ebay it's more than $40 cheaper. You get it for $33 + $35 shipping = $68 total

On Electric Rider the 48v25a is $160 + $12.62 = $172.62 total

That is a little over a hundred dollars cheaper.

Not to mention that you can get a 48v 45a infinion if you ask Keywin (the infinion seller) for probably $110 shipped. Compare that to the $243 you would spend on the comparable model from Electric Rider.

Some food for thought.

 

[Drunkskunk]

As stated, the 408 can handle 40 amps. Mine is handling it at 74 volts right now. 48 volts won't stress it too much.

you will love the imidiate start, and wonder why you didn't start out with it. But be aware that starting that way will eat amps and cost you a good chunk of range. Its worth it to me, but others have diffrent oppinions.

Variable voltage is sort of pointless for a BLDC motor. You get better efficancy and preformance form PWM. (Fixed voltage, pulse with modulated). Electricrider.com likes to overstate things. There claim about testing vairable voltage is about like Denver Colorado claiming they haven't had a tidal wave in over 50 years!

 

[jimw1960]

I have instant start controller already, just that it is a 36 v system. I guess I'm going to stick with instant start, fixed voltage.

Tostino, where are you seeing Infineon controller on ebay for $33? The 48v/30a Infineon that I found there costs $119, but only $4.20 for shipping. Can you provide a link?

 

[tostino]

http://cgi.ebay.com/48V-600W-brushless-controller-for-E-bike-scooter_W0QQitemZ300248682281QQihZ020QQcategoryZ11332QQcmdZViewItemQQ_trksidZp1742.m153.l1262

 

[jimw1960]

Tostino, That controller on the link you posted won't do. It's only rated for 600-800 watts. At 48v, that's only a 15a controller.

 

[tostino]

Tostino, That controller on the link you posted won't do. It's only rated for 600-800 watts. At 48v, that's only a 15a controller.

Read the amp limit. Honestly, no one should pay attention to the watt ratings on almost any e bike parts... They are very different for the same part from different sellers.

It's very handy to have a sticker that says 600w for legal reasons even if the controller is able to put out over 1500w.

Edit: And just to be clear, that is the same infinion controller that ComCycle is selling.

 

[jimw1960]

Thanks for the info, Tostino.

I ended up going with the 4825 controller from Electric Rider. It's a lot more money than getting the one on ebay from e-crazyman in china, but it already comes with the long cables to reach the wheel and compatible connectors, so that saves me shopping for connectors and building cables. Plus, I like doing business with US company it goes bad or I need to exchange it.

 

[nicobie]

http://cgi.ebay.com/48V-600W-brushless- ... m153.l1262

I just bought one of those from Keywin and am running it on a 600w BMC motor @ 60v. The max amps I've ever gotten out of it is 26 and it shows 23a topped out on level ground.

Yesterday I soldered in the shunt. I might have gotten carried away as now I'm hitting peaks of 44a and 32a cruising along at top speed. If I remember right, the wattsup read 2400 max watts. I might be pushing the BMC motor a bit, but it does go like hell.

Nick

 

[tostino]

http://cgi.ebay.com/48V-600W-brushless- ... m153.l1262

I just bought one of those from Keywin and am running it on a 600w BMC motor @ 60v. The max amps I've ever gotten out of it is 26 and it shows 23a topped out on level ground.

Yesterday I soldered in the shunt. I might have gotten carried away as now I'm hitting peaks of 44a and 32a cruising along at top speed. If I remember right, the wattsup read 2400 max watts. I might be pushing the BMC motor a bit, but it does go like hell.

Nick

Lmao I was about to tell you to solder the shunt by the time I got halfway through the post, but the next line of text said you just did . What top speed are you reaching with it? And if you were using another controller before, how does it compare?

 

[Muad'dib]

If I run a fixed voltage controller would the LVC function in the controller be good enough to dispense with a BMS? I will likely do balancing with the charger, so if I have good LVC protection in the controller there would be no reason to hassle with BMS, right?

 

[dnmun]

if you run SLA or nicad, a fixed value for the LVC on the controller is ok.

if you use lifepo4, it is best to use the BMS on the battery to monitor the individual cell voltages. lifepo4 stays well balanced, but it is really bad to over discharge them, they never come back.

the reason the LVC is on the controller is to protect the controller from low battery voltage. if the input voltage drops too low, then the voltage regulators will not function and the 5V buss could end up losing control of the processor and the FETs could short out if they aren't properly switched by the processor.

can't believe that guy wouldn't buy the shenzen controller from keywin on the presumption that he didn't understand the market here. i don't think we have had any vendor go so far to change their product to meet our needs, almost immediately after richard discovered how the overclocking helped solve the puma problem, keywin had the new infineon in knuckles' hands.

i recently got to work on one of the shenzen controllers and hacked the LVC down to 40V from 59.5V, and swapped out one the power resistors to get the controller to run on 48V rather than 72V lifepo4. all based on what richard and knuckles did last year.

 

[Muad'dib]

Got it, thanks. I also think he made the wrong move. I've been reading up on controllers for the last few days and these Infineons seem to be the best performance and reliability for half the cost (or less).

 

[jimw1960]

Yeah, but try sending it back to China if you have trouble with it. I am satisfied with my choice. Maybe I'll experiment with the Infineon for the next bike I convert, but I have too many projects going on right now an was willing to pay extra for the plug-and-play convenience of the Electric Rider controller.

 

[nicobie]

Hi tostino,

It's been so damn windy here lately that I've been having trouble figuring out my exact top speed. Yesterday I did a 25 mile ride and as close as I can guess it tops out at 35 mph on the flats. Before the shunt mod it was 30 mph. This is the only controller I've used on this motor (new build). I don't like the way it responds to the throttle. It seems to be either full on or off with not much or a middle. with the torquey BMS motor it's a bit hard to control on the starts.

 

[dnmun]

nick, i think you are dealing with the soft start problem that is programmed into the infineons. keywin is currently trying to get the processors reprogrammed from his source so there is no delay in the throttle response.

that is the common complaint about the infineon.

do you pictures of the inside of the 6FET infineon? from when you soldered the shunt.

the term variable voltage refers to the battery pack voltage. that the controller will work with different battery packs over a range of voltages.

if you use a 36V controller at 48V then if you depend on the LVC in the controller, you have to reset it to a higher value for your 48V pack, and you can adjust the power resistor to keep the input voltage to the 12V regulator in range. but since the regulator can work up to 40V above the 12V buss, which can get dragged up to 16V, the concern about swapping the power resistor is mute. but if you convert from 72V to 48V, you have to reprogram the LVC and remove one of the power resistors. i just did that on a 72V infineon controller for duane.

 

[Muad'dib]

Yeah, but try sending it back to China if you have trouble with it. I am satisfied with my choice. Maybe I'll experiment with the Infineon for the next bike I convert, but I have too many projects going on right now an was willing to pay extra for the plug-and-play convenience of the Electric Rider controller.

I regret taking that shot at you of saying you made the wrong decision. Having an in country supplier is a nice thing if something needs replacement.

Even so, for my project I went ahead and ordered a custom 48v 50amp controller from Keywin (ecrazyman@gmail.com). I sent him a picture and a verbal list of all the connectors I wanted (plug and play) and he is sending it out tomorrow for $100. Not bad for a controller made to my specs.

 

[tostino]

I would also like to add that I sent my controller to be looked at by Keywin after I had a problem, and it was quickly dealt with and sent back fixed.

@Above: Yeah, $100 is not bad at all considering it is a 50a controller!