mid drive 8Fun

[Robert lafleur]

I just received(5days ago) my new conhismotor
Off Road 29er Electric Bike 48V 750W 29er Mid-Drive+9-speed+48V 12Ah Li-ion Battery+LCD Display

since I can have up to 9 PAS and 9 gears... there are then multiple options to stay at a fixe speed(ex: 30km/h)... To be able to find the best combination of gears to choose,... I would like to have a power/amp/volts read on the controller...

is there a way to get this option???

 

[Lenny]

Cycle Analyst is a great tool and you can configure it to read anything and everything on your bike. Very versatile.
http://www.ebikes.ca/product-info/grin-products/cycle-analyst.html

Once connected to the vehicle's power bus, the Cycle Analyst calculates and shows the following information:

• Volts, Watts, Amps: The instantaneous electric power being drawn from the battery.

• Amp-Hours, Watt Hours: The net energy that has been pulled from the pack since the meter was reset. The accumulated amp-hours let you know the remaining energy in the battery pack with far greater accuracy than a voltage or LED indicator.

• Speed, Distance, Time: All of the basic features of a bicycle computer, including the average and maximum trip speeds, plus a total distance odometer.

• Regen, Wh/km: There are several quantities this meter will calculate that you don't get with other instrumentation, such as the % extra range that was gained from regenerative braking, as well as the vehicle's average energy use in Watt-hours per kilometer or mile.

• Peak Currents and Voltage Sag: Records the maximum forwards and regenerative currents as well as the minimum voltage on the battery pack.

• Total Battery Cycles and Amp-Hours: Retains life cycle information on the vehicle's battery pack, such as how many charge and discharge cycles the pack has experienced and the total amp-hours that were delivered over its entire life.

Furthermore, the Cycle Analyst has the ability to over-ride the user's throttle and regulate the power delivered to the motor, turning an otherwise dumb ebike into an intelligent device with a user programmable speed limit, current limit, and low voltage cutout.

• Speed Limit: This has the utility of providing legal compliance to the speed cap imposed on ebikes in most jurisdictions. When used with a full throttle, it serves as a cruise control on the electric bicycle. It can also be beneficial to riders who want to increase their torque and power by using a higher voltage battery, without simultaneously increasing their top-end speed.

• Current Limit: An adjustable amps limit is useful to prevent damage to the batteries from excessive current draw, to increase the range that you'll get on a charge, and to protect the motor controller and motor in setups that draws too many amps.

• Voltage Cutout: A low voltage cutout is used to protect a battery pack from being discharged too deeply, which can cause cell reversals in NiMH/NiCad packs, permanent cell damage in Lithium packs, and sulfation in Lead Acid batteries. The programmable low voltage rollback allows you to set an appropriate low voltage point tailored to your pack.

 

[R3d_N3ck]

Your controller is probably the C961. Download the manual for this.
It won't show amps, volts or watts.

Setting the PAS limit speed is pretty simple.
You could set it for 30km/h. The throttle will override the pas limit.

 

[Robert lafleur]

thanks R3d... my controller is in fact the C961... I had seen the speed limit... and thought it did not work since the throttle overrides it... but know I understand why the PAS was working at low speed but not at a higher speed... but my initial intoragation remains... what is the best gear ratio to maintain a given speed.. since DC motors have a efficiency curve, there must then be a optimal motor rotation!!! I have figured out that the minimum PAS rotation is about 70 RPM and the maximum around 140 RPM... that's why I want a amp/volt/power reader

 

[rmosier]

This is interesting. I have a very similar setup. Bafang BBS02 750 watt motor with a 50V 12.3 AH battery. With the speed limit set to 50kph, and the tire size set correctly at 29" the motor cuts off at 31 mph (which is correct) but it also cuts off using the throttle. I have the newest version motor and controller. Is there a setting to change to allow the motor to ignore the speed limit while using the throttle? I would like to keep the speedo accurate rather than change the tire size.

 

[Robert lafleur]

to rmosier... yes there seems to be a way... In my case I have the C961 controller and the throttle overrides the speed limit set by the user, but not the ones set by the manufactor at the different PAS modes... luckely for me... at PAS 9 the limit is 100% so it will assist me at speeds above 50km/h, I can reach easily 60 km/h... there is a discussion on the Endless-sphere forum showing how to rear and reprogram your controller... It seems very complicated to me... but know I understand why my throttle does not work without peddal assist... it is programmed that way... It can be changed... http://endless-sphere.com/forums/viewtopic.php?f=28&t=58780

 

[Robert lafleur]

to "crazy lenny"... I have gone to the link for the Cycle Analyst... looks very good, but not that easy to install, have you installed one on a ebike like mine?

 

[rmosier]

To Robert Lafleur - Thank you for this information. I'm not sure if I'm up to it, it seems a little complicated. But I am going to look into it. Thanks again.

 

[R3d_N3ck]

Thanks Robert for the re-programming link but that looks way to scary for me.
This may sound silly but I only set 3 levels of PAS.
At level 3 I think it runs about 50% power and full power with the throttle so I never setup any more.
Does someone have specs on the power levels for each PAS level?

The battery level indicator never seems to work on my bike.
I think this is due to the battery being a LiFePO4 and maintains a high voltage until it is almost empty.
The indicator displays full while waiting at traffic lights.
It indicates 3/4 while cruising on the flat (46km/h).
The hills on my commute are not very steep and with a bit of effort I can keep close to 40km/h.
When climbing a hill the battery indicator starts to drop to about 1/4.
This is a sure sign that the load on the battery is increasing uphill as the RPM slows down.

My bike only has 26" wheels so at cruising speed I'm pedalling around 95rpm.
The motor appears to be happier at this rpm than slower but this may be an illusion.
The motor may just be holding back in cruise because we are close to max rpm.

My 11T cog and tools have finally arrived so I will be installing it over the weekend.
If it goes slower, the motor prefers a faster rpm.
If it goes faster, the motor likes a slower rpm.

I won't be buying the cycle analyst as once we know the magic RPM number, we won't need cycle analyst any more.

 

[Robert lafleur]

to R3d_N3ck... reprogramming really looks difficult...

as for the PAS levels... I used to use only 3, but now I have set it at 9...

I have found specs for the 9 levels of the PAS for the C961, but after reading on how to program it.. I see than you can do whatever you what, and I am not sure that all C961 are programmed the same way...

on my C961 with 3 levels of PAS... the no-load RPM for level 1 is 77, level 2 is 96 and level 3 is 130... if I go to 9 levels of PAS, the no-load RPM's are.: 60, 69, 78, 97, 106, 117, 126, 133... ... meaning that max level is about the same, but the low PAS is very different.

I find that when I follow other cyclist, it is easier to have more chose of PAS to follow them...

I agree (half way) with you about the Cycle Analyst... I have read that the magic RPM for the 350W(?) 8fun is about 106 RPM... but the Cycle Analyst would still be useful as a "real" battery indicator...