SZZS specific CEF50-main thread (initial builds and troubleshooting related only)

Bengy22

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Aug 25, 2022
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Power is equal to voltage x current. So if you have a 540whr battery/36v the current is 15a but a 540whr/43=12a so the 43v needs to handle less current than the 36v battery.

It is a little easier to find 36v external batteries than 43v.
This assumes the 43v controller is limiting the amps further to get the same amount of watts. Do we have any idea if there is actually two different models or if one just has 36v firmware that also allows more amps? And if they are the exact same motor if both bikes are geared the same the lower but more amps 36v should in theory give slightly more torque with the higher voltage giving a slight rpm increase. Reminds me of the uart bafang motors where you could get a 48v model and stick a 52v battery to get more power. Of course they then released a 52v model but it also lowered the current to match the watts of the 48v. With then later firmware unlocking the full amps with 52v software.
 

mike_kelly

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This assumes the 43v controller is limiting the amps further to get the same amount of watts. Do we have any idea if there is actually two different models or if one just has 36v firmware that also allows more amps? And if they are the exact same motor if both bikes are geared the same the lower but more amps 36v should in theory give slightly more torque with the higher voltage giving a slight rpm increase. Reminds me of the uart bafang motors where you could get a 48v model and stick a 52v battery to get more power. Of course they then released a 52v model but it also lowered the current to match the watts of the 48v. With then later firmware unlocking the full amps with 52v software.
Two different motors 36v and 43v. Not assuming anything watts is watts. A 43v 500whr battery has the same power as a 500whr 36v battery. 500whr!
A 500whr 43v battery can produce 12a for an hour.
 

Bengy22

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Aug 25, 2022
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Two different motors 36v and 43v. Not assuming anything watts is watts. A 43v 500whr battery has the same power as a 500whr 36v battery. 500whr!
A 500whr 43v battery can produce 12a for an hour.
Well my question is are they really two different motors and not just two identical motors with different firmware on the controller. The reason why I assume the ladder is with the bbs02, bbshd, m620 (I don't know enough about the others) even though they get listed as 48v and 52v motors the only difference is that firmware. The hardware inside is perfectly fine on the lower voltage models to run the higher volts. That when you think about it it makes sense bafang would do this as needing to redesign and manufacture two different motors and or controllers would cost a lot more than just different software.

Yes the same amount of power storage, but the discharge power of the 43v would be greater if both have the same amount of amps pulled from them. Say 15a, 36*15= 540w , 43*15= 645w. I'm not very familiar with the canbus stuff and how easy it is to mess with the firmware settings. I'm not super familiar with the m820 and what amps the controller pulls for the two voltages so this just an example: If at 36v say it pulls 15a or 540w peak, now at 43v bafang wants the motor to peak around the same so they limit the controller to 13a or 559w. You can see the controller is actually good for 2a more, if you find a way to unlock the controller you can get the full 15a. With previous motors what people would do if they had the lower voltage (like back when they didn't offer a 52v option only 48v) is that they would just run the higher voltage and it was fine, but I have heard some cases some firmware being set to throw a overvoltage error if it goes above the normal max. So people got in and either changed the firmware to not through an error, or when bafang came out with 52v firmware they got in and upped the max amps back to what it was with the lower voltage. Something might be possible with the m820 to do the same, getting the same amps as the 36v but with a 43v battery
 

temon10

Well-known member
Feb 8, 2022
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Malang, Indonesia
Well my question is are they really two different motors and not just two identical motors with different firmware on the controller. The reason why I assume the ladder is with the bbs02, bbshd, m620 (I don't know enough about the others) even though they get listed as 48v and 52v motors the only difference is that firmware. The hardware inside is perfectly fine on the lower voltage models to run the higher volts. That when you think about it it makes sense bafang would do this as needing to redesign and manufacture two different motors and or controllers would cost a lot more than just different software.

Yes the same amount of power storage, but the discharge power of the 43v would be greater if both have the same amount of amps pulled from them. Say 15a, 36*15= 540w , 43*15= 645w. I'm not very familiar with the canbus stuff and how easy it is to mess with the firmware settings. I'm not super familiar with the m820 and what amps the controller pulls for the two voltages so this just an example: If at 36v say it pulls 15a or 540w peak, now at 43v bafang wants the motor to peak around the same so they limit the controller to 13a or 559w. You can see the controller is actually good for 2a more, if you find a way to unlock the controller you can get the full 15a. With previous motors what people would do if they had the lower voltage (like back when they didn't offer a 52v option only 48v) is that they would just run the higher voltage and it was fine, but I have heard some cases some firmware being set to throw a overvoltage error if it goes above the normal max. So people got in and either changed the firmware to not through an error, or when bafang came out with 52v firmware they got in and upped the max amps back to what it was with the lower voltage. Something might be possible with the m820 to do the same, getting the same amps as the 36v but with a 43v battery

There U can find that 36v has higher amp than 43v and 48v version. I can flash my M510 FC 1.0 from 48v to 43v vice versa but get battery display not correct. Some said M820 locked by Bafang so we can't flash to another v firmware.
 

Bengy22

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Aug 25, 2022
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There U can find that 36v has higher amp than 43v and 48v version. I can flash my M510 FC 1.0 from 48v to 43v vice versa but get battery display not correct. Some said M820 locked by Bafang so we can't flash to another v firmware.
Thanks for your input, That is the one issue I remember on my bike when I went from 52v to 48v but I personally was more of a fan of voltage compared to % so it didn't really bother me. I wonder with it being open source if they will fix that issue, I know they did with the bbshd firmware but I never got around to flashing new firmware that would correct the % as again I never used it. That's what I was worried about with the m820, locking down the firmware is no fun!
 

mike_kelly

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It has been firmly established that there are two separate motors. The purpose of this motor is to facilitate lightweight lower power emtb. If you want a higher power motor get a M510.
 

Bengy22

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Aug 25, 2022
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It has been firmly established that there are two separate motors. The purpose of this motor is to facilitate lightweight lower power emtb. If you want a higher power motor get a M510.
I'm sorry I must have missed that, I must admit I haven't fully kept up with this thread, can you link me to this? I was in interested in a dyno graph that would showcase the difference the extra volts and less amps would have but I couldn't find that.
 

dvng

Member
May 21, 2021
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41
Malaysia

There U can find that 36v has higher amp than 43v and 48v version. I can flash my M510 FC 1.0 from 48v to 43v vice versa but get battery display not correct. Some said M820 locked by Bafang so we can't flash to another v firmware.
If its tunable, i don’t see any reason to change the firmware. I believe there will only be update for bugs in the future.
 

Waynemarlow

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Dec 6, 2019
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Power is power no magic. 410whr battery has the same power at 36v or 43v.
Guys, please be aware of basic electrical calculations,
V x A = Watts which is what you feel as power from your motor.
Whr's is simply the Watts x hours which in our case is the energy contained in your battery, that has nothing to do with the power of the motor.
So if Amps were to be equal
36 volts x 15 amps = 540 watts
however
43 volts x 15 amps = 645 watts.

So which motor will be the more powerful feeling to you and I ?

Please bare in mind that Bafang will almost certainly not have the same amperage in 36 and 43 volt versions so that both motors will be roughly equivalent in how they feel to you and I. There are a number of advantages in higher voltages but with the modern processor controlled motor there will be little difference, maybe cadence being slightly higher in the 43 volt unit but even that now with the way the controller operates is being negated.
 
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Waynemarlow

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It would be really really interesting to fit a 48 volt battery to the 43 volt motor ( or even a 43 volt battery to a 36 volt motor ), my M600 48 volt motor will accept without any high voltage warnings a 52 volt battery. It in some ways is a much nicer motor as it lifts the best cadence to about 10rpm higher which suits my legs which had been more used to analogue pedal speeds.
 

mike_kelly

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I'm sorry I must have missed that, I must admit I haven't fully kept up with this thread, can you link me to this? I was in interested in a dyno graph that would showcase the difference the extra volts and less amps would have but I couldn't find that.
 

mike_kelly

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Aug 11, 2022
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Guys, please be aware of basic electrical calculations,
V x A = Watts which is what you feel as power from your motor.
Whr's is simply the Watts x hours which in our case is the energy contained in your battery, that has nothing to do with the power of the motor.
So if Amps were to be equal
36 volts x 15 amps = 540 watts
however
43 volts x 15 amps = 645 watts.

So which motor will be the more powerful feeling to you and I ?

Please bare in mind that Bafang will almost certainly not have the same amperage in 36 and 43 volt versions so that both motors will be roughly equivalent in how they feel to you and I. There are a number of advantages in higher voltages but with the modern processor controlled motor there will be little difference, maybe cadence being slightly higher in the 43 volt unit but even that now with the way the controller operates is being negated.
36 volts 17.9 amps = 645 watts
however
43 volts x 12.5 amps = 500 watts.

So which motor will be the more powerful feeling to you and I ?
 

mike_kelly

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The watt-hours of the battery has nothing to do with a feeling of "power". The peak draw of the motor determines how much power it can put out. Without driving the motor out spec by messing with it. The motor puts out around 400w peak and how you supply it electricity to do that does not matter.
 

temon10

Well-known member
Feb 8, 2022
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Malang, Indonesia
My Frame kit arrive safely after 3 weeks delayed of Ied holiday. I will assemble as soon as possible, hope can test it next Tuesday. It is Size S with 720Wh battery.

WhatsApp Image 2023-05-19 at 20.08.17.jpg
 

Bengy22

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Aug 25, 2022
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If anything I take that comment to indicate that it is just software not hardware, "the same motor, but the voltage is different", at least that's how I view it. None the less it would take someone to experiment with their motor to see for sure, I do think there's a possibility though that if you hooked the 36v motor to the 43v battery it would work and give you more power compared to getting a 43v motor. But can't know for sure unless someone wants to test it to see if it throws an error or it doesn't like the m600 comment above
 

Waynemarlow

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Dec 6, 2019
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It would be really really interesting to fit a 48 volt battery to the 43 volt motor ( or even a 43 volt battery to a 36 volt motor ), my M600 48 volt motor will accept without any high voltage warnings a 52 volt battery. It in some ways is a much nicer motor as it lifts the best cadence to about 10rpm higher which suits my legs which had been more used to analogue pedal speeds.
Not meaning to reply to myself but even my DP242 display acknowledges the 52 volt battery on startup and gives a pretty accurate battery display in percentage. Probably to enable one display fits all voltages across the range.
 

stuff

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Nov 3, 2022
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Spain
To @LAnton and @stuff , this button don't have led indicator when switch on? View attachment 115095

That doesnt look like the oem one, should hace a CAN interface and thats why it doesnt have light. Check the DP E171 manual.

Just came back from a ride, had to abort due to a flat :(
36k , 1200m elevation gain and still one led was on in the DP E180. Mostly between level 2 and 3.

Im quite surprised by the power it has, today with the speed sensor working properly it was amazing.

Included headset is trash, second ride and creaks :/ i’ll go for the nukeproof
 

mike_kelly

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To @LAnton and @stuff , this button don't have led indicator when switch on? View attachment 115095
About that button. It is supposed to be a control with assist levels etc so if it is canbus it would be a communitions line. You don't want to connect it to a battery like that, might burn it out. Canbus devices talk to each other over the canbus so it is not a simple switch.
Canbus.png

HOWEVER, canbus should always have four wires. Power, Ground and the two communications wires. So something is wrong with that picture with only two wires.

canbus1.png
 
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