I see the one in the link is listed as suitable for 48V.
I saw in a few posts the 52V is illegal what’s the reasoning behind this ? If the battery voltage does not give more speed
48 V Bafang KT Build
- Thread starter Baz the balloon man
- Start date
I saw in a few posts the 52V is illegal what’s the reasoning behind this ? If the battery voltage does not give more speed
They're not necessary. Small hub-motors with plastic gears, like AKM 100 can do 15A at 48v with no problems, provided you don't use the high speed one, like Cwah did. The next size up, like the ones you see on Pendletons and MXUS XF07 can do about 17A, which is enough power for most people to climb steep hills. There are many different, but similar Bafangs, all different sizes, so It's difficult to make guidelines, but I'd be happy to use them all at 48v and 15A, and I'd probably go with 17A myself because I have some very steep hills in my area. Also, you have to be mindful of the winding speed. If it's more than 250 rpm at 36v, it's probably a good idea not to go to high on the current unless it's a chunky motor, like the AKM 128.
Never buy a motor unless you know its speed.. I forgot to mention that wheel size is also important, since running a high speed motor in a small wheel is safer for the motor than in a large one.
I imagine it's because anything over 50V is under different electrical rules since it doesn't count as ELV (extra low voltage)
?? Afaik? The optimum rpm of a motor IS directly related to the voltage level of its power supply. Hence the 'bonus features' of overvolting or running a motor supplied with a 36v battery pack and controller with a 48v Pack and suitable control system to achieve 33% increase in both achievable top speed(rpm) and torque to climb with.
EN15194 isn't a legal requirement, although meeting it is enough to presume compliance with the law, EAPC regs 1983/2015, which itself doesn't limit voltage. So technically 52V doesn't appear to be illegal.
EN15194 is meant to align with the Low Voltage Directive (LVD) which covers systems of 75V DC and over, and SELV is limited to 120V DC, so nominal 52V (max 58.8V) isn't even excluded from EN15194 on those counts, _but_ EN15194's abstract has this to say, and as usual the rest is behind a paywall:
"This European Standard specifies requirements and test methods for engine power management systems, electrical circuits including the charging system for the design and assembly of electrically power assisted bicycles and sub-assemblies for systems having a rated voltage up to and including 48 V d.c. or integrated battery charger with a nominal 230 V a.c. input."
So without an onboard charger a 52V battery falls outside EN15194 and can't be compliant with it, with one it could be. (It's pretty clear this isn't really what they meant to say.)
I've heard that 52V nominal is regarded as being 'rated' 48V for the purpose of EN15194 assessment. As with motor ratings if we only policed clear breaches we'd be too busy for a lack of clarity to matter.
EN15194 is meant to align with the Low Voltage Directive (LVD) which covers systems of 75V DC and over, and SELV is limited to 120V DC, so nominal 52V (max 58.8V) isn't even excluded from EN15194 on those counts, _but_ EN15194's abstract has this to say, and as usual the rest is behind a paywall:
"This European Standard specifies requirements and test methods for engine power management systems, electrical circuits including the charging system for the design and assembly of electrically power assisted bicycles and sub-assemblies for systems having a rated voltage up to and including 48 V d.c. or integrated battery charger with a nominal 230 V a.c. input."
So without an onboard charger a 52V battery falls outside EN15194 and can't be compliant with it, with one it could be. (It's pretty clear this isn't really what they meant to say.)
I've heard that 52V nominal is regarded as being 'rated' 48V for the purpose of EN15194 assessment. As with motor ratings if we only policed clear breaches we'd be too busy for a lack of clarity to matter.
The thing is that bikes complying with EN15194 are exempt from needing licence, registration etc. If your bike doesn't comply, then it's up to you to argue it out -maybe in court.
Then comes the next question: Why would you want 52v, anyway? The speed has to be limited to 25km/hr. Where is the advantage of 52v, when most motors are designed for 25km/hr at 36v or 48v? Except in fringe circumstances, 52v will not be advantageous. most people wanted it for the extra speed and power.
Yes EN15194's probably easier. For me, using 1P 20Ah cells, the benefit of 52V is being able to add capacity in 8% steps, rather than having to double weight going from 1P to 2P.
That won't apply widely at present but standards should take care not to needlessly exclude technologies, particularly in a fast evolving field like ours. Who needed lasers in 1960?
That won't apply widely at present but standards should take care not to needlessly exclude technologies, particularly in a fast evolving field like ours. Who needed lasers in 1960?
I just saw the posts that 52V is illegal if it does not increase speed or say speed is still Limited by controller say on a Cargo bike .
But what you are saying is it not of any use on any bike that’s limited to the 15.5 MPH ? So waste of time using one .
My wife wants me to build an ice cream Pedelech not a big heavy thing as Ice cream sales out side schools is being restricted by prohibited time access for motor vehicles enforced by camera .
I thinking of something that is light works with dry ice and possibly has a small solar panel to help with charging but easy to move around on .
So if we say had a solar panel that is producing 48V DC how would we then get a charger to work with it that would cut off once a battery is fully charged .
I asked my solar guy but he was unsure as not familiar with something like this .
I thinking of something that is light works with dry ice and possibly has a small solar panel to help with charging but easy to move around on .
So if we say had a solar panel that is producing 48V DC how would we then get a charger to work with it that would cut off once a battery is fully charged .
I asked my solar guy but he was unsure as not familiar with something like this .
It depends whether a crank motor or hub-motor and the motor's winding speed (Kv). Ideally, you need a motor that maxes out at around 1.3 times your modal riding speed for a hub-motor, or 1.3 times your modal pedal speed for a crank-drive. The motor will become increasingly less efficient the higher that ratio goes.
You chose a solar charge controller that has an adjustable charge voltage, and set it to 54.6v, or if your solar panels don't go that high, you use a step-up charge controller. Unless you have a massive canopy, you can forget charging from solar. You'd be better to invest in a spare battery.
Most solar ebike systems use a 'boost' solar charge controller and a panel(s) with voltage lower than the battery voltage. The charge controller is programmed to output the fully charged voltage of the battery, so 42V for a 36V system, 54.4V for a 48V system.
My panels produce about 18V, and the charge controller steps that up.
There are cheap Chinese versions and rather expensive Dutch ones.
Elejoy EL-MU400SP is the Chinese version that I use. About £30. Can't remember the Dutch name, but they are about £200, and I don't remember a 48V model.
BTW I wouldn't put too much effort into the ice cream outside schools idea as I think you'll get banned immediately. Schools do not want distractions at the pickup/drop-off points/times for safety reasons.
Interesting project in the right place.
Interesting project in the right place.
I will look into this so is it the BMS in the battery that stops the input current once full not the charger ?
Related Articles
-
MTF Enterprises announces acquisition of EMU Electric Bikes- Started by: Pedelecs
-
Wisper 806T folding bike wins Which? ‘Best Buy’- Started by: Pedelecs
-
Sustrans calls for protected cycle lanes- Started by: Pedelecs
-
Amazon launch their first UK e-cargo micromobility hub- Started by: Pedelecs
