icerider
100 W
In May 2014, I bought a used Terratrike Cruiser with a PL350 (old style I2C G1 console) Bionx system. The bike is circa 2009 and appears to be a “Power Cruiser”, originally delivered from Terratrike with the Bionx system installed.
When I took possession of the bike, it came with two Bionx batteries. One of these appears to have good capacity remaining and is capable of about 15 miles in the top level of support (level 4). With an advertised capacity of 9.6AHr, this seems reasonable, not great, but reasonable. The second battery was STONE dead.
After several attempts to recover the “dead” battery, I figured … why not… and opened the case. The battery was wired 10s6p as expected. The old I2C Bionx system does not have a battery management system as such. The pack of 60 cells is bulk charged without any attempt at “balance”.
Disassembly yielded 60 LiMn 1600mAh 18650 cells in varying states of life. Roughly 30 of them proved to be dead, leaky, and unrecoverable. The other 30 retain some “spark” of life and I have managed to recover 10 of them more or less fully.
Living in Arizona and now knowing that the Bionx system had no balance circuitry made for an interesting idea. “Why not a Solar Power Cruiser?” A quick look for solar panels showed up an initial problem. Solar panels are HEAVY. Most 100W solar panels weigh 16-21 pounds (7.5-10 kg) and come with heavy frames and tempered glass faces designed to withstand the impact of golf ball sized hail without damage. A worthy goal for an installed panel, but not very necessary for an electric bike that is already probably at least a little allergic to rain, let alone golf ball sized hail. Further looking produced an interesting candidate (https://www.renogy-store.com/100watts-bendable-panel-p/rng-100db.htm). A 100W Monocrystalline bendable solar panel. Bendable…hmm…but more important, the weight is 3 pounds (1.35kg). OK, that might be workable…not cheap, but workable. The panel is 41x21 inches (1049x530mm). Maybe very workable. Next question is simple…where to mount this thing. So take a picture of the bike from the side, drop it in PowerPoint, and take a line the right length and start waving it around over the picture. Ah ha…did I mention that I live in Arizona? My bike is about to have an umbrella.
On to the next problem. The solar panel produces 17.7V and 5.90 amps at the max power point, and I need 42V for a 10s battery. OK, I need a boost power supply. Amazon to the rescue with (http://www.amazon.com/gp/product/B00F0E0F2E), a DROK DC Voltage Converter Regulator 10-32V up converted to 36-60V Boost Regulated Power Supply. Now they caution that it needs enhanced cooling over 80 watts and I still live in Arizona and it is getting on July. A 50mm 12 volt fan will fill the bill nicely. And a project box from the local radio shack, and oh yes, a low-loss blocking diode with very low forward voltage drop. Say like (http://www.amazon.com/gp/product/B0087YQKQ4) a Vishay 30A 100V trench MOS barrier Schottky diode…just what the doctor ordered. Now we are ready to try to build this thing.
I started with taking the 10 good 18650s recovered from the dead Bionx battery, wired them 10s1p and put them back into the Bionx battery case and wired up all the other stuff in the project box. I wired the solar panel to the input of the boost supply and to the little 50mm fan. I wired the output of the boost supply into the Bionx battery and dragged the whole thing into the sun (Arizona strikes again). I adjusted the output voltage to 42 volts. I mounted the mess to the Power cruiser with ¾ inch PVC schedule 40 water pipe and now I had a Solar Cruiser with a battery capacity of 1.6Ah and a total energy of 59 Whr.
Hmm, this probably isn’t going to work very well but what the hell, it is a down and dirty prototype. If I get it up to speed without using the motor, and then go REALLY gentle on the throttle, and keep the required battery (and panel) power to say no more than 100W then I can go 14mph !!!!! on level ground. Or so says the simulator (http://www.ebikes.ca/tools/simulator.html). I fed it Bionx PL350 Motor, 36 volt, 20a controller, 150kg full recumbent with fat old guy and 78% throttle. I don’t believe the 14mph, but maybe this won’t be a complete failure…maybe.
So now the 59Whr (1.6Ah) battery is all charged up to 42V, the sun is shining …sorta, we are getting into monsoon season and there are clouds around. I push the menu (start) button and the Bionx system powers up – first time in a couple of years this battery has come to life in the system. The circuit board in the older “dead” Bionx battery is still mostly? WORKING. This is a BIG step in the right direction.
Down the drive and out onto our little rural road. Lo and behold, if I get it up to 12 mph with my legs and then use the throttle VERY gently, I get a couple of bars on the power meter (couple of bars out of say 16 bars) – not too far maybe from 100W. And the bike rolls on at 12 mph without pedaling at all. If the power is split 50/50 between battery and panel then I am drawing roughly 1.5A (1C) from the poor abused 18650s in the Bionx shell and 50 W from the panel and boost supply. OK, so far kinda sorta working, let’s try a little more throttle – BANG low voltage cutout and the system is locked.
OK, put it into diagnostic mode, which on the I2C Bionx system appears to ignore low battery. I continue to ride using the throttle. With the diagnostics running , I see the low voltage warning (err 25), but there is no low voltage cutout, just the diagnostic warning. When I give it more throttle, the voltage drops like a stone to around 30 volts and the bike continues to roll at maybe 13 mph. OK, the first test is a rousing, but limited, success. I now have a “working” battery to play with (and my other unmodified good Bionx battery is not at risk) and the solar system is trying to do what it should, I can hear the little 50mm 12v fan running faster (no load) and slower (as the solar panel is loaded by the boost supply and the voltage drops). Don’t have any diagnostics except the voltage report from the Bionx controller, but when I coast, the voltage comes back up to 38+ volts … and RISING, the solar system is charging the Bionx battery. This thing is working. The first ride went for 2 miles and never got above about 13 mph. Not too far from what the simulator predicted, but not NEARLY enough fun.
So, everything is sort of working. What I need now is a higher battery capacity. I can buy a replacement brick of lithium batteries for the Bionx battery shell for around $500 from electricrider (http://www.electricrider.com/Lithium-Battery-Replacement-for-Bionx-Kits-p/bionxrebuild.htm)– and I still may, but that seems like a big investment just to take the next step to a Solar Power Cruiser.
Hobbyking to the rescue, did you know they have a new US warehouse. Two 5s 20C 5000mAh LiPo bricks (http://www.hobbyking.com/hobbyking/store/__9174__Turnigy_5000mAh_5S_20C_Lipo_Pack.html) and an iMAX balance charger are $150.
The two 5s 20C 5000mAh LiPo bricks fit with a LOT of room to spare into the Bionx battery shell. And, even if I know the LiPo can be dangerous, I also know that I am using them VERY gently. Say the Bionx system peaks at 750W, that is 20A at a nominal 37 volts or 4C out of the 20C LiPo bricks. And the charge rate is around 0.5C at best. Pretty undemanding life for an RC LiPo. But, it is Arizona, and they will have to be in the sun to charge, and the garage is uninsulated…so we’ll keep a watchful eye on them. Charged and balanced the LiPos and put them into the Bionx battery shell with three power leads (high, mid, and ground) sticking out of the case for charging. i also extended their balance leads outside the case so I can check and correct out-of-balance problems.
So now for the first REAL ride on the Solar Power Cruiser. It is early – pre dawn. The battery is fully charged and I am anxious to know how far my new 5Ah (185Wh) battery will carry me. I set the console to max assist and use the throttle freely. I also peddle consistently but not particularly hard. I work to keep the speed UP on uphills for efficiency in the Bionx direct drive motor. I rarely drop below 17mph. When the pack (10s) voltage reaches 35 volts, I have gone 14 miles (13.2 Wh/mile) on a loop in relatively hilly terrain with a total loss/gain of 700 feet. WOW, that is better than I expected, pretty darn good for a cheapie rebuild of a Bionx battery. But that was in the dark. The sun is now up and low in the sky, I put the back wheel of the cruiser up on a bucket to give it a better solar angle. I manually track the sun just correcting the pointing maybe once per hour for 4 hours from 7 to 11 am. At 11 I walk past the bike and notice the little 50mm fan is REALLY racing. I check voltages and the battery is back to 42V and the boost supply is taking virtually nothing from the solar panel so the little 12v 50mm fan is getting about 20 volts from the panel, no wonder it is racing. With a fully charged bike I set out at 11am to see how much further I go with the sun shining. I get 14 miles on the same loop again at max assist and using the throttle freely. When I get back to the starting point, the battery voltage is still at 38.5 volts (about half full). I ride the circuit again, I am getting a little bored and am using the throttle a LOT this time around. At about 26 miles I have dropped to 35 volts under load and back off the assist to finish the last two miles. I finish the 28 miles right at 35 volts. The solar panel has essentially doubled my useful range in the highest assist mode.
So at this point, I am elated. I ride for fun, and do not commute on the bike. 14 miles is a good morning ride and even 20 miles is enough to go to the nearest town for groceries, etc. This is going to work. For the next three weeks, I ride the bike every morning and just leave it in the sun when I am done with the morning ride. My wife keeps an eye on it and rolls it into the garage when the little 50mm fan starts to get fast and noisy. It is the height of monsoon and she also takes it inside if it looks like it is going to rain. In three weeks it fails to fully charge by noon on only one particularly dark and gloomy day (Arizona remember).
I have now ridden for four weeks and been on a charger only once and that was to be sure the LiPos were properly balanced. I got an RC balance checker (http://www.amazon.com/gp/product/B003Y6E6IE) an Integy C23212 Lipo Voltage Checker, and have kept track of the LiPo cell voltages. At full charge, the cells are at 4.17 volts plus or minus 0.01 volts. At 90% discharge they are at 3.4 to 3.5 volts with a total range among the cells of less than 0.10 volts. After roughly 20 full cycles they still have better than advertised capacity ~5200mAh.
So what is the bottom line? Dogman is right, if all I wanted was range, the batteries are lighter than the solar panel (but not too much lighter). On the other hand, on weekends I ride with friends and use the lowest 2 assist levels. In that case, I can reasonably expect to go 60 miles starting first thing in the morning. If we kept riding through mid-day, I would expect to have a nearly full battery at 2pm after 7 hours at 12-14 mph. That is starting to sound like a reasonable touring solution, at least in sunny Arizona. Besides, it is kind of fun to have an electric bike that never has to be charged from the wall, just left in the sun and ridden whenever I want.
There is also an interesting “bug” in the ointment. Starting out at 42 volts, that old I2C Bionx controller occasionally enters “never land” and locks up. It is easy to clear, just push the “menu” button and wait for 20 seconds or so and the console will “reboot” and become useable again. When this happens in the diagnostic mode, the controller shows err 26 (no comm with battery). I think it is related to the fact that the max voltage the Bionx system was expecting is from 41-41.5 volts and the diagnostic display shows 42.4 volts at startup fully charged. The other unique problem is that the battery gauge was showing nothing (no bars). I reset the battery gauge and it worked once, but did not work after recharging. I tried again and reset the battery gauge when the battery was full. I rode it half empty in midday sun and left it to charge. When I came back the battery was fully charged 41.7 volts but the battery gauge still showed only 50% charge (it didn’t move at all. This suggests that one of the functions of the circuit board in the battery in the I2C (old) Bionx system is to act like a cycle analyst and integrate the received charge. Since I am charging the batteries direct to the battery terminals and NOT through the battery circuit board, this feature does not work. I am going to try resetting the battery gauge immediately before every ride (when the battery is fully charged) and see if that works. After being reset, the battery gauge seems to follow the battery voltage as a guide to energy remaining, and the curves for LiMn and LiPo are relatively similar.
In any case, I am having a great time with my Solar Power Cruiser.
When I took possession of the bike, it came with two Bionx batteries. One of these appears to have good capacity remaining and is capable of about 15 miles in the top level of support (level 4). With an advertised capacity of 9.6AHr, this seems reasonable, not great, but reasonable. The second battery was STONE dead.
After several attempts to recover the “dead” battery, I figured … why not… and opened the case. The battery was wired 10s6p as expected. The old I2C Bionx system does not have a battery management system as such. The pack of 60 cells is bulk charged without any attempt at “balance”.
Disassembly yielded 60 LiMn 1600mAh 18650 cells in varying states of life. Roughly 30 of them proved to be dead, leaky, and unrecoverable. The other 30 retain some “spark” of life and I have managed to recover 10 of them more or less fully.
Living in Arizona and now knowing that the Bionx system had no balance circuitry made for an interesting idea. “Why not a Solar Power Cruiser?” A quick look for solar panels showed up an initial problem. Solar panels are HEAVY. Most 100W solar panels weigh 16-21 pounds (7.5-10 kg) and come with heavy frames and tempered glass faces designed to withstand the impact of golf ball sized hail without damage. A worthy goal for an installed panel, but not very necessary for an electric bike that is already probably at least a little allergic to rain, let alone golf ball sized hail. Further looking produced an interesting candidate (https://www.renogy-store.com/100watts-bendable-panel-p/rng-100db.htm). A 100W Monocrystalline bendable solar panel. Bendable…hmm…but more important, the weight is 3 pounds (1.35kg). OK, that might be workable…not cheap, but workable. The panel is 41x21 inches (1049x530mm). Maybe very workable. Next question is simple…where to mount this thing. So take a picture of the bike from the side, drop it in PowerPoint, and take a line the right length and start waving it around over the picture. Ah ha…did I mention that I live in Arizona? My bike is about to have an umbrella.
On to the next problem. The solar panel produces 17.7V and 5.90 amps at the max power point, and I need 42V for a 10s battery. OK, I need a boost power supply. Amazon to the rescue with (http://www.amazon.com/gp/product/B00F0E0F2E), a DROK DC Voltage Converter Regulator 10-32V up converted to 36-60V Boost Regulated Power Supply. Now they caution that it needs enhanced cooling over 80 watts and I still live in Arizona and it is getting on July. A 50mm 12 volt fan will fill the bill nicely. And a project box from the local radio shack, and oh yes, a low-loss blocking diode with very low forward voltage drop. Say like (http://www.amazon.com/gp/product/B0087YQKQ4) a Vishay 30A 100V trench MOS barrier Schottky diode…just what the doctor ordered. Now we are ready to try to build this thing.
I started with taking the 10 good 18650s recovered from the dead Bionx battery, wired them 10s1p and put them back into the Bionx battery case and wired up all the other stuff in the project box. I wired the solar panel to the input of the boost supply and to the little 50mm fan. I wired the output of the boost supply into the Bionx battery and dragged the whole thing into the sun (Arizona strikes again). I adjusted the output voltage to 42 volts. I mounted the mess to the Power cruiser with ¾ inch PVC schedule 40 water pipe and now I had a Solar Cruiser with a battery capacity of 1.6Ah and a total energy of 59 Whr.
Hmm, this probably isn’t going to work very well but what the hell, it is a down and dirty prototype. If I get it up to speed without using the motor, and then go REALLY gentle on the throttle, and keep the required battery (and panel) power to say no more than 100W then I can go 14mph !!!!! on level ground. Or so says the simulator (http://www.ebikes.ca/tools/simulator.html). I fed it Bionx PL350 Motor, 36 volt, 20a controller, 150kg full recumbent with fat old guy and 78% throttle. I don’t believe the 14mph, but maybe this won’t be a complete failure…maybe.
So now the 59Whr (1.6Ah) battery is all charged up to 42V, the sun is shining …sorta, we are getting into monsoon season and there are clouds around. I push the menu (start) button and the Bionx system powers up – first time in a couple of years this battery has come to life in the system. The circuit board in the older “dead” Bionx battery is still mostly? WORKING. This is a BIG step in the right direction.
Down the drive and out onto our little rural road. Lo and behold, if I get it up to 12 mph with my legs and then use the throttle VERY gently, I get a couple of bars on the power meter (couple of bars out of say 16 bars) – not too far maybe from 100W. And the bike rolls on at 12 mph without pedaling at all. If the power is split 50/50 between battery and panel then I am drawing roughly 1.5A (1C) from the poor abused 18650s in the Bionx shell and 50 W from the panel and boost supply. OK, so far kinda sorta working, let’s try a little more throttle – BANG low voltage cutout and the system is locked.
OK, put it into diagnostic mode, which on the I2C Bionx system appears to ignore low battery. I continue to ride using the throttle. With the diagnostics running , I see the low voltage warning (err 25), but there is no low voltage cutout, just the diagnostic warning. When I give it more throttle, the voltage drops like a stone to around 30 volts and the bike continues to roll at maybe 13 mph. OK, the first test is a rousing, but limited, success. I now have a “working” battery to play with (and my other unmodified good Bionx battery is not at risk) and the solar system is trying to do what it should, I can hear the little 50mm 12v fan running faster (no load) and slower (as the solar panel is loaded by the boost supply and the voltage drops). Don’t have any diagnostics except the voltage report from the Bionx controller, but when I coast, the voltage comes back up to 38+ volts … and RISING, the solar system is charging the Bionx battery. This thing is working. The first ride went for 2 miles and never got above about 13 mph. Not too far from what the simulator predicted, but not NEARLY enough fun.
So, everything is sort of working. What I need now is a higher battery capacity. I can buy a replacement brick of lithium batteries for the Bionx battery shell for around $500 from electricrider (http://www.electricrider.com/Lithium-Battery-Replacement-for-Bionx-Kits-p/bionxrebuild.htm)– and I still may, but that seems like a big investment just to take the next step to a Solar Power Cruiser.
Hobbyking to the rescue, did you know they have a new US warehouse. Two 5s 20C 5000mAh LiPo bricks (http://www.hobbyking.com/hobbyking/store/__9174__Turnigy_5000mAh_5S_20C_Lipo_Pack.html) and an iMAX balance charger are $150.
The two 5s 20C 5000mAh LiPo bricks fit with a LOT of room to spare into the Bionx battery shell. And, even if I know the LiPo can be dangerous, I also know that I am using them VERY gently. Say the Bionx system peaks at 750W, that is 20A at a nominal 37 volts or 4C out of the 20C LiPo bricks. And the charge rate is around 0.5C at best. Pretty undemanding life for an RC LiPo. But, it is Arizona, and they will have to be in the sun to charge, and the garage is uninsulated…so we’ll keep a watchful eye on them. Charged and balanced the LiPos and put them into the Bionx battery shell with three power leads (high, mid, and ground) sticking out of the case for charging. i also extended their balance leads outside the case so I can check and correct out-of-balance problems.
So now for the first REAL ride on the Solar Power Cruiser. It is early – pre dawn. The battery is fully charged and I am anxious to know how far my new 5Ah (185Wh) battery will carry me. I set the console to max assist and use the throttle freely. I also peddle consistently but not particularly hard. I work to keep the speed UP on uphills for efficiency in the Bionx direct drive motor. I rarely drop below 17mph. When the pack (10s) voltage reaches 35 volts, I have gone 14 miles (13.2 Wh/mile) on a loop in relatively hilly terrain with a total loss/gain of 700 feet. WOW, that is better than I expected, pretty darn good for a cheapie rebuild of a Bionx battery. But that was in the dark. The sun is now up and low in the sky, I put the back wheel of the cruiser up on a bucket to give it a better solar angle. I manually track the sun just correcting the pointing maybe once per hour for 4 hours from 7 to 11 am. At 11 I walk past the bike and notice the little 50mm fan is REALLY racing. I check voltages and the battery is back to 42V and the boost supply is taking virtually nothing from the solar panel so the little 12v 50mm fan is getting about 20 volts from the panel, no wonder it is racing. With a fully charged bike I set out at 11am to see how much further I go with the sun shining. I get 14 miles on the same loop again at max assist and using the throttle freely. When I get back to the starting point, the battery voltage is still at 38.5 volts (about half full). I ride the circuit again, I am getting a little bored and am using the throttle a LOT this time around. At about 26 miles I have dropped to 35 volts under load and back off the assist to finish the last two miles. I finish the 28 miles right at 35 volts. The solar panel has essentially doubled my useful range in the highest assist mode.
So at this point, I am elated. I ride for fun, and do not commute on the bike. 14 miles is a good morning ride and even 20 miles is enough to go to the nearest town for groceries, etc. This is going to work. For the next three weeks, I ride the bike every morning and just leave it in the sun when I am done with the morning ride. My wife keeps an eye on it and rolls it into the garage when the little 50mm fan starts to get fast and noisy. It is the height of monsoon and she also takes it inside if it looks like it is going to rain. In three weeks it fails to fully charge by noon on only one particularly dark and gloomy day (Arizona remember).
I have now ridden for four weeks and been on a charger only once and that was to be sure the LiPos were properly balanced. I got an RC balance checker (http://www.amazon.com/gp/product/B003Y6E6IE) an Integy C23212 Lipo Voltage Checker, and have kept track of the LiPo cell voltages. At full charge, the cells are at 4.17 volts plus or minus 0.01 volts. At 90% discharge they are at 3.4 to 3.5 volts with a total range among the cells of less than 0.10 volts. After roughly 20 full cycles they still have better than advertised capacity ~5200mAh.
So what is the bottom line? Dogman is right, if all I wanted was range, the batteries are lighter than the solar panel (but not too much lighter). On the other hand, on weekends I ride with friends and use the lowest 2 assist levels. In that case, I can reasonably expect to go 60 miles starting first thing in the morning. If we kept riding through mid-day, I would expect to have a nearly full battery at 2pm after 7 hours at 12-14 mph. That is starting to sound like a reasonable touring solution, at least in sunny Arizona. Besides, it is kind of fun to have an electric bike that never has to be charged from the wall, just left in the sun and ridden whenever I want.
There is also an interesting “bug” in the ointment. Starting out at 42 volts, that old I2C Bionx controller occasionally enters “never land” and locks up. It is easy to clear, just push the “menu” button and wait for 20 seconds or so and the console will “reboot” and become useable again. When this happens in the diagnostic mode, the controller shows err 26 (no comm with battery). I think it is related to the fact that the max voltage the Bionx system was expecting is from 41-41.5 volts and the diagnostic display shows 42.4 volts at startup fully charged. The other unique problem is that the battery gauge was showing nothing (no bars). I reset the battery gauge and it worked once, but did not work after recharging. I tried again and reset the battery gauge when the battery was full. I rode it half empty in midday sun and left it to charge. When I came back the battery was fully charged 41.7 volts but the battery gauge still showed only 50% charge (it didn’t move at all. This suggests that one of the functions of the circuit board in the battery in the I2C (old) Bionx system is to act like a cycle analyst and integrate the received charge. Since I am charging the batteries direct to the battery terminals and NOT through the battery circuit board, this feature does not work. I am going to try resetting the battery gauge immediately before every ride (when the battery is fully charged) and see if that works. After being reset, the battery gauge seems to follow the battery voltage as a guide to energy remaining, and the curves for LiMn and LiPo are relatively similar.
In any case, I am having a great time with my Solar Power Cruiser.