Although we initially had the eZee controllers modified and advertised as being 48V capable, there have been enough failures at this point that we are going to back down and only suggest them for 36V operation. Under heavy load conditions at 48V, such as going up a long steep hill full throttle, there is a possibility of a mosfet frying. This didn't happen in our original 48V testing as we were using 8AH NiCad packs which would sag to about 43V at 20A currents. But the trend recently has been for "48V" 16 cell LiFePO4 batteries (more properly called 52V packs), and these deliver a higher voltage to the controller under load which can more easily put it over the edge.
For customers currently running their eZee kits at 48V, we recommend using a Cycle Analyst to limit the current draw to 15 amps max. When we receive the new controllers alluded to in the previous paragraph and have validated their robustness at 48V, then we give the option of exchanging these for the eZee controllers so that you have the 48V capability originally implied.
June is bicycle month in Vancouver and this year is off to a rocking start with one of the warmest and sunniest summer weather systems we've had in ages. The bike paths are overflowing with happy riders and new commuters, and tons of bicycle themed events are taking place around town
The Cycle Analyst firmware version 2.1 is now officially released through the entire line of CA products. For most users there is little material difference, the trip amp-hours and distance can now go up to 1999 Ah or Km respectively, instead of 199, and the #poles variable for CA-DP devices now goes up to 99 instead of just 14 poles. But for those who like to tinker, there are extra pads now used for datalogging and external control of the speed or current limit, as explained on the first announcement last year. For those who are in and out familiar with microchip programming, the hex code is available for download here.
On the subject of Cycle Analysts and data logging, we now have a cable assembly prepared that enables you to record the data coming off a CA into your computer or laptop through the standard USB port. This device requires soldering to the Gnd and Tx pads on the Cycle Analyst circuitboard. It includes a built in serial -> USB converter, so it will show up as a COM port on your computer and the data can be viewed and logged with hyperterminal or any other standard terminal program.
It seems that a lot of people who were purchasing the high current Cycle Analyst models did not already have a shunt on hand, so we are now carrying a large 0.25 mOhm shunt that is suitable for 200-300 amps of continuous current and up to 600 amps peak, which will cover a wide range of large EV applications. This part is listed on our accessories store page.
We have also sourced a great metal enclosed 12V halogen light series that mates perfectly with our DC-DC converters. So for those who want more brightness than the LED lights, these halogen lights with a 12V DC-DC will command more than just a presence on the road. We have both 5W and 10W bulb options available, and will be releasing a dual light in the near future that will give up to 20W of illumination.
There is finally an answer to those who have been turned off the rear conversion kits because it meant downgrading from a 9 speed shifter system to 7 or 8 speeds in order to accommodate a screw-on freewheel. The company which produces our 11 tooth 7 and 8 speed freewheels now makes a 9 speed version as well, which we have in stock with an 11-32 tooth gear range. It is of course a bit wider than the 7 speed freewheels, so most installations will require spacers on the axle and some spreading of the dropouts.
The e-brake lever is a device designed to cut power from the motor controller as soon as someone squeezes on the brakes. It's a sensible safety idea, but we stopped carrying them several years ago because the quality of the actual brake levers was so poor that in several cases the lever arm itself failed, leaving the rider without an operable hand brake. Well we now have a decent quality all-aluminum e-brake lever for the eZee kits. It plugs into the 4-pin PAS connector and effectively disables the throttle power when you are squeezing the brakes. It could be easily adapted to other controller systems as well. The switch mechanism is a magnetic reed device mounted outside the housing, normally open, which closes contact and the levers are pulled.
It turns out that trying to include a waterproof on/off button in our fully epoxy potted bike lights posed some interesting challenges. But few thing will phase us, and after a lot of work we've managed to sort through all the challenges and are re-introducing the button LED lights by the end of this week. The rear light is now slightly larger and brighter with 8 LEDs, and both the front and rear lights feature onboard memory as well. When the light is powered off, it remembers what mode it was in (on, off, or flashing) and returns to that state when power is re-applied. Pressing the button then cycles through each of the modes.
Our spring 2009 shipment of Nine Continent motors was unpacked this week and includes a few new items. In addition to replenishing the stock of front 20" wheels, we have also added to the mix:
- 26" hub motors with the higher-rpm 6-turn winding (what we call the 2806 hub)
- 20" rear hub motor with 6-turn winding
- 700c rear motors with the 7 turn winding
The 2806 front motor in a 26" rim is a good combination for people who want to go faster while still sticking to a 36V battery system. The rear motors are here by popular request. The axle spacing is 135mm and works fine with a 5 or 6 speed freewheel. 7 speed or higher requires additional spacers on the right and slight spreading of your dropouts. They have a threaded side cover on the left to accommodate a screw-on disc rotor. The rims are centered on the hub rather than dished, so the wheel is offset about 1cm to the left as supplied. They'll be available through our website some time next week.