Upgrade - Ananda MC5-B0 Controller

[wilhian]

Your battery uses the LG MG1 cell, as cells go it is one of the very mediocre 10a rated cells.
One wouldn't want to draw more then 16a from that battery.

Thanks for the info. The 16A controller is enough.

 

[Nealh]

One is governed ultimately y the quality of the cells used and the BMS continuous rating, no use running at more then 20a if using crap/mediocre cells.
Ideally one has to opt for 20a cells which there are only a few good ones and they are now like gold dust and generally means building your own or bespoke built by someone else.

 

[wilhian]

One is governed ultimately y the quality of the cells used and the BMS continuous rating, no use running at more then 20a if using crap/mediocre cells.
Ideally one has to opt for 20a cells which there are only a few good ones and they are now like gold dust and generally means building your own or bespoke built by someone else.

I am back

Do rear engines have a rev limit? RPM ?

Thank you very much for your attention. Knowledge is very valuable and sharing it is even more valuable.

 

[Nealh]

Every hub is wound for a certain speed/rpm so yes they have a max speed for the voltage. Theoretically one can have 150rpm to 500+ rpm, the faster the rpm rating the less torque the motor gives for that voltage.
Typically for 36v 201rpm is good for approx. 15mph for 26" or 16.5mph for 28"/700c.
230rpm 18mph 26" & 19mph 28" , 270rpm 20.5mph 26" & 22mph 28", 328rpm 25mph 26" & 27mph 28". These are the typical speeds often for sale for geared hubs.
Occasionally on may see other rpm like 250 or 300.

One can overvolt hubs to gain more speed, doing so 24v to 36v can gain 50% speed and torque & 36v to 48v 33%.

The heavier larger Direct drive hubs tend to be the faster ones from 370rpm to 500rpm +, these are for high power and higher cruising speed.

 

[Nealh]

Speed though comes as a compromise and this in the main is range, for faster speed one needs more wh/ah capacity.

 

[wilhian]

Speed though comes as a compromise and this in the main is range, for faster speed one needs more wh/ah capacity.

I see, but the engine itself doesn't have a rev limit? I saw in some advertisements saying that the engine had 370 rpm.

 

[sjpt]

I see, but the engine itself doesn't have a rev limit? I saw in some advertisements saying that the engine had 370 rpm.

For a given motor and given voltage there is a rev limit (as in Nealh's post #24 above).

 

[Nealh]

A motors rpm is dependant on the coil windings so the rpm is limited by the windings.

 

[wilhian]

For a given motor and given voltage there is a rev limit (as in Nealh's post #24 above).

Sorry, i dont see #24 above.

 

[wilhian]

A motors rpm is dependant on the coil windings so the rpm is limited by the windings.

Sorry, i dont see #24 above.

 

[wilhian]

Every hub is wound for a certain speed/rpm so yes they have a max speed for the voltage. Theoretically one can have 150rpm to 500+ rpm, the faster the rpm rating the less torque the motor gives for that voltage.
Typically for 36v 201rpm is good for approx. 15mph for 26" or 16.5mph for 28"/700c.
230rpm 18mph 26" & 19mph 28" , 270rpm 20.5mph 26" & 22mph 28", 328rpm 25mph 26" & 27mph 28". These are the typical speeds often for sale for geared hubs.
Occasionally on may see other rpm like 250 or 300.

One can overvolt hubs to gain more speed, doing so 24v to 36v can gain 50% speed and torque & 36v to 48v 33%.

The heavier larger Direct drive hubs tend to be the faster ones from 370rpm to 500rpm +, these are for high power and higher cruising speed.

Great explanation.

With this information I can calculate my gear ratio for better performance and durability.

Best Regards.

 

[wilhian]

Great explanation.

With this information I can calculate my gear ratio for better performance and durability.

Best Regards.

I was wrong.

Engine RPM is independent of gear ratio. right?

 

[Nealh]

Yes.
The rpm speeds I mentioned are variable +/- 1 mph.
36v 201rpm for instance becomes 270rpm approx. if over volted to 48v so will run faster. Generally one has to select the rpm for the type of riding or terrain used.
If flat terrain then one can select a faster wound motor, but if one is in hilly terrain then a slow wound motor is better because one gets more torque. Again a very heavy rider or someone towing stuff should opt for lower rpm.

 

[Nealh]

If one wants speed and to use gearing then a mid motor is the option to select.

 

[sjpt]

Engine RPM is independent of gear ratio. right?

As Nealh said, 'yes'. To clarify, that is motor RPM. On a hub drive RPM relates directly to speed; but on a mid drive the speed is dependent on the gear and the motor rpm.

 

[wilhian]

Thanks for the tip.

One more question:

Could a controller for 36v 350w/500w be used on a 250w motor?

I'm setting up a kit with controller so I can update the engine in the future. The Bafang 850c dispaly (which I would like), shows in the manual that it is possible to change the current between 6A ~ 50A... is this what I need to configure for a 250w motor?

In other words, is it safe for me to use this 350w controller on a 250w motor setting the current on the display?

Thank you very much.
Wilhian

Hi, all good?

the new controller and display arrived and installed for testing.

It works, but the wheel doesn't turn. am i doing wrong?

my controller uses torque sensor, it's connected, but I haven't installed it on the bike yet.

Thanks,
Wilhian

 

[wilhian]

As I say ignore the 250/350/500w rating that sellers use and be guided by the current rating of the controller, the current rating needs to be a bit less then the specs of the battery continuous current. Some so called 250/350w cheaper controllers only have a 13a current rating whilst other decent ones will have up to 20a rating.

Going back to your Q of 'Could a controller for 36v 350w/500w be used on a 250w motor?'

Then yes if the battery continuous rating is known and is greater then the controller or the display has the ability to to reduce the controller current rating.

A display that allows current adjustment is a good option and can be tailor set to a little under the battery rating. If one has a battery that has only a 15a continuous rating then one doesn't want to draw more then 15a as the cells will likely be stressed, in such a case one would stop the current draw at around 12a. It is always best to buy or use a battery with the greater continuous current rating then the controller rating.

Hi, all good?

the new controller and display arrived and installed for testing.

It works, but the wheel doesn't turn. am i doing wrong?

my controller uses torque sensor, it's connected, but I haven't installed it on the bike yet.

thanks.

 

[Nealh]

Your TS BB won't work unless the controller kit you bought is TS compatible, if you have bought a non TS controller kit then it will only work with generic std BB and a cadence PAS magnet/disc set up.

 

[wilhian]

Your TS BB won't work unless the controller kit you bought is TS compatible, if you have bought a non TS controller kit then it will only work with generic std BB and a cadence PAS magnet/disc set up.

I did not understand.

the old setup:
controller
torque sensor
display
motor

new configuration:
controller (new)
torque sensor (new)
display (new)
accelerator (new)
brake sensor (new)
engine (old)

the only thing that didn't change was the engine.

tested using the accelerator, the engine accelerated but did not turn the wheel. when i accelerate with the wheel in the air, it doesn't work?

I took the bike to install the torque sensor and tomorrow I'll be able to do the quick test.

 

[Nealh]

Can you supply a link to the kit bought ?