Hi Methods, no, I do not want to further experiment. I conclude that 25S is a bad idea, and thank you for putting my feet back on the ground, again.
First, let me introduce my Cromotor Commuter ("CC") to you:
What you see is the following:
- Cromotor hidden behind the pannier bags, laced into a 26" HALO SAS rim with black 14G Sepim spokes from JRH
- Lyen 18FET 4110 controller behind the seatpost
- FS Fusion-bikes.de frame painted blue metallic with a rear Fox SL shock. There are two watertight grey boxes (in the traingle of the front fork and lower main tube, and in the triangle below the controller) that contain the main connections. All electric wires from front to rear (or vv) are led through the black wire cover at the lower tube.
- Rear Avid 203mm rotor with Juicy Seven hydraulic caliper. DIY double switch for regen and rear brake-light attached to the brake handle (Left).
- Front 160mm rotor with Elixer Seven hydraulic caliper (Right). No regen or brake-light switch attached.
- Front Rockshox REBA air SL (100mm) fork, painted blue metallic.
- Touring steering bar, with DOT-approved 12V MoFa light and two blinkers. On the left hand side I have the 3-speed switch, regen, brake-light, mirror. On the right hand side I have the blinker activator and the throttle. In the middle is the CAv2 with current throttle hardwired. You can also see the GoPro (movies to follow).
- Rear pannier bags (completely watertight) are attached to the sideframes of a Freeload frame that is attached to the frame. Therefore, they do not benefit from suspension, and I need to be careful when hitting bumps. The rear light / brake light and the rear blinkers are also attached to the Freeload frame. A 74V-12V DC converter is attached to the underside of the Freeload frame, as well as a strobe for the blinkers.
- Single speed freewheel with chain tensioner, and attached to the 44t front cog. Front and rear derailleur have been removed.
This morning's commute was very enjoyable. Yesterday evening I had calibrated the CA up to 0.1A using the foam-cutter function of my ICharger (9.9A at 40.0V from the battery negative to one of the phase wires). So the results mentioned below are as correct as I can get them.
I took a very hilly trajectory (up to 20% inclines) with a total distance of 30km.
I started with a voltage of 83.8V, ended with 75.3V, and used a total capacity of 645Wh. My total pack capacity is 1kWh (74V 13.5Ah), so I am at 65% discharge. Perfect for a commute.
The 18.2 Wh/km really reflects the fantastic regen facilities when going down hill. I regenerated almost 120Wh, aka 21.3%. That really makes a huge difference!
In order to save juice and to NOT push the motor / controller to their limits, I limited the controller to 40A/100A and the CA to 40A as well. Still, going uphill showed some nice peaks at 58A max, and going downhill generated currents up to 32A (2.3kW). Don't try this with anything else than Lipo's! With my 13.5Ah pack, this means I was charging with more than 2C.
- Chain still keeps falling off, despite the chain tensioner, due to misalignment of rear freewheel and front cog. I need to buy another chain guide.
So, the next building efforts will be in finalizing the battery box for within the triangle. I don't want to work on the fiberglass box with the kids nearby, for fear of their health. At the moment the battery is in the left pannier. Due to it's low position and due to the counterbalance of the 3kg charger + 2kg laptop in the right pannier, there is no real unbalance between left or right. But the front-rear balance is obviously not preferable.
Anyway, I love it !
To do list:
- Finalize the battery box
- Post pics of the build and make some nice vids
- Get the CAv3 that is still stuck in customs
- Attach the temp probe and start logging temps when going uphill