My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
- Thread starter justin_le
- Start date
panurge said:
That indeed would have been so fun. Me and AnSo were talking about trying to connect with you while going through Italy but assumed you were much further south. Bruno was such an amazing character and it's nice to see that he's been widely appreciated too. We have some good video footage of the visit and now that we're back in Canada it should be faster to get these edited and live for others to see.
Anyways I'm back in Canada now, recovering from jetleg, the entire body is still a little stiff from all that exercise and inadequate stretching. Gained 3 pounds compared to when we left, which I'm hoping is mostly muscle weight
Miles said:
You sure know what's coming next on my project list Miles! Before that though, for our upcoming wedding in 2 weeks, I'm thinking of building the worlds most inefficient electric boat. Imagine a wood-burning hottub, floating in the ocean, with a couple peltier devices between the furnace and the cold ocean water to power a small electric propeller and scoot around the bay at 1-2 knots
For any Farsi speakers, we finally got a link to the final interview piece inside Tehran from just before we wrapped things up and disassembled the trike:
[youtube]W9CysLNVbOY[/youtube]
and there is a fair bit of the raw footage available from the Associated Press site:
http://www.aparchive.com/metadata/MEEX-Iran-Solar-Cyclists/2369a9685cf6322c8d4d78b94fd5d34f
maitilupas
100 W
- Joined
- Mar 6, 2018
- Messages
- 146
really nice , and now your famous in Iran!
Can't wait to see the wood powered boat.
So what are you going to do with the solar trike now? It should probably go in the ebike museum somewhere. But it takes up a lot of space, so I could imagine keeping it disassembled.
So what are you going to do with the solar trike now? It should probably go in the ebike museum somewhere. But it takes up a lot of space, so I could imagine keeping it disassembled.
eCue
10 kW
a BIG Congratulations happy everyone is safe and the Trip was a success SWEET you guys were IMO in some scary territory 
happy everyone is safe and the Trip was a success SWEET you guys were IMO in some scary territory Cephalotus said:
So I've not got all my raw data available for anyone who wants to look at it here:
https://www.dropbox.com/s/kt8in0sfmvdd5y9/Justin%20Suntrip%20Log.zip?dl=0
The start and stop point of the files isn't exactly at the start of each day depending on when I remembered to reset the databox logging device, but most of them are reasonably close. This is just raw log data, we're working on some web tools that will do automatic day by day summaries of all the stats and enhancements to the trip analyzer page so that it can handle and display way larger data files without chocking.
Still coming soon! But I'm going to start with another near perfect day which was the first day of the race. Conditions in the week before the Suntrip gathering were terrible (lots of people pedaled their rigs to Lyon in endless downpour), and then improved during the June 14th-19th preamble from Lyon to Chamonix, and finally on the race start day it couldn't have been better, with bright skies, clean air, and tailwinds. It was like everything was going to fall into place.
We left from France at 10am, went over two 1500m peaks, rode through a flat valley in Switzerland, and then climbed up and over a 2000m pass. Descended from there into Italy having covered 199km, pretty much spot on our initial daily target. If you look at the graph data, we were doing 30-35 kph on the flat valley, hovered above 20kph for most of the hill climbs while consuming 1400-1600 watts, and clamped our speeds to 40-50kph on the descents with regen.
On the solar, it shows a total of 4kWhr, but that's because I hadn't reset the logger from the previous day, so when we started it was already at 1200 Wh giving us a total of 2.8 KWhr. Since the battery was charged in the morning before the 10am departure we didn't collect anything from the sunrise to 10am point.
Because there was so much mountain climbing this was a perfect leg to showcase the benefits of DD hub with regen, though it also became apparent that we didn't have our setup quite as dialed as would be ideal. I had configured each Phaserunner controller to do a max of 12 amps of regen (so 900 watts net from both controllers) in order to keep the combined solar+regen charge current to just a little over 1C on the LiGo batteries to keep the cells happy.
However, what that meant is that if the hill was steep enough that 900 watts regen was not sufficient to keep the speed clamped, then the bike would continue to accelerate, and the faster down you went the LESS regen torque you would have on the motor because at a higher RPM fewer Nm are needed for a given braking power and regen wattage. We would only get more than 900 watts of regen once the speed of the bike had reached a point where the back-emf voltage of the motors was above the pack voltage which would be at +45 kph, and then suddenly the regen would increase again since the controller has no way to limit it.
This resulted in a situation where if our goal was to maximize the amount of battery charge recovered on the downhill, it was often advantageous to still use the mechanical brakes to keep our speed at say 30 kph. If we didn't use mechanical brakes, the speed might increase to 45 kph; we'd still be getting just 900 watts into the battery but the descent would be over that much sooner so the total amp-hours recovered would be less, with a much larger share of our potential energy would have gone into wind drag losses. It also meant that pedaling on the steep downhills like this was similarly counter productive, it would just mean going downhill faster less time spent getting this fixed regen into the battery.
Here's a link to just the data from the 2nd hill pass.
http://www.ebikes.ca/tools/trip-analyzer.html?trip=nbc8ZL
You can see that we get 42% regen range extension, with some sections where we were going above 50 kph and having more like 1200-1400 watts of regen from back-emf, but mostly we stayed slower using the brakes to keep it in the 900 watts regime.
Ideally, we would have had a setup with either higher C rated cells that can be charged at 2-3C, or a larger battery pack, that could take full advantage of absorbing the potential regen energy from the motors and Phaserunners. In that scenario with the phaserunners not having a max regen curren tlimit, we could have set a speed on the descent of say 30 kph, rowed and pedaled on the downhill sections too, probably had 1500+ watts going into the battery and likely doubled the amount of regen energy captured. Not that 42% regen is bad, but it doesn't represent the true potential in this scenario.
Another thing that this first day was very useful for was giving us an idea of how many Watt-hours we needed for a given elevation climb. Here is the data on this pass at 100m elevation steps.
View attachment 1
As a good ballpark we could see that we were averaging about 100 watt-hours consumed for each 100m of elevation gain, and that became a really useful rule of thumb for budgeting our battery reserves on future hill climbs during the entire trip. If we knew that there was a 500m elevation climb ahead, we'd aim to ensure we had at least 500 watt-hours in the battery, or about half full, so that even if we lost sun while climbing there would still be enough in reserve to make it to the top. Once at the top, a flat battery is no issue since it's all regen going down, but if you run flat while climbing a hill then moving a behemoth of an ebike like this with no motor assist is a real grind.
You can see that on this 2000m pass, we dialed it pretty well. We took two breaks on the climb to allow some solar charging while the motors would cool, and only just hit the system's low voltage rollback right at the top of the mountain. The CA's LVC was set to 29V, but that includes the voltage drop along the long lead from the battery to the two motor controllers. The actual voltage as seen by the datalogger directly connected to the packs was a bit higher at 30.3V.
And for those who want to see a video of this first day of the Suntrip race, Aaron here at Grin has finished editing a bunch of the gopro footage that we took on the first day. We wanted to see most of the other riders for one last time before everyone went their own way at their own pace.
[youtube]pvQny7iZO3U[/youtube]
I tried to have this ready like a month ago but too much logistics challenge dealing with large video files and restricted internet access while on the road. So now we're publishing the trip video of the first day right after one of the riders has already completed the entire 12K+ km and finished the race in Guangzhou!
https://www.thesuntrip.com/raf-van-hulle-join-guangzhou-canton/
https://www.thesuntrip.com/raf-van-hulle-interview/
More to come...
[youtube]pvQny7iZO3U[/youtube]
I tried to have this ready like a month ago but too much logistics challenge dealing with large video files and restricted internet access while on the road. So now we're publishing the trip video of the first day right after one of the riders has already completed the entire 12K+ km and finished the race in Guangzhou!
https://www.thesuntrip.com/raf-van-hulle-join-guangzhou-canton/
https://www.thesuntrip.com/raf-van-hulle-interview/
More to come...
philf
1 kW
Speaking of "Perfect Days"... When exactly is yours, Justin? This coming weekend? (Apologies if it appears elsewhere - you guys have been all over the various media, but everything I've read merely alludes to the month). I don't think I have the power to will every day in August to be perfect for you and Anne-Sophie, but I'll try .
.
wturber
1 MW
philf said:Speaking of "Perfect Days"... When exactly is yours, Justin? This coming weekend? (Apologies if it appears elsewhere - you guys have been all over the various media, but everything I've read merely alludes to the month). I don't think I have the power to will every day in August to be perfect for you and Anne-Sophie, but I'll try
Yeah that was my thot. What's he doing compiling ride data? Doesn't he have a wedding to prepare for? Oh wait!! This is Justin. Last minute prep is his standard. ;^)
Great video BTW.
solarEbike
100 W
Now we're getting to the good stuff! Thanks for posting this analysis and the sample logs. Zooming in on the longer regen segments helped me better understanding what's going on.
Well, this would seem to explain some of the unexpected behavior I've been seeing on long and/or steep descents like increase/decrease in braking power around the 45 kph mark and more/less regen amps than my max regen amps setting on the PR. When comparing to your example speeds, it helps that I'm using the same motor (Grin 5T DD), wheel size (20") and battery (36V). Maybe if I re-read the definition of back-emf for the 11th time it will eventually sink in...
Now I get why I saw ~40% regen on an extra-slow ride I took a few weeks back when the same hilly loop usually gets me 20-25%. I was descending the same hills at around 20 mph (32 kph) instead of the usual 30 mph (48 kph) or so. I knew the potential energy from the top to the bottom of the hill hadn't changed but it wasn't clear to me why I was getting so much more regen. (I also used less battery energy on the ascent.)
Excellent. I've been struggling with this aspect of on-the-fly range estimation. Now that I have the GPS Analogger working with the solar firmware, I'll have to figure out my Wh per 100m number.
So over 4% voltage drop? Was this a deliberate design decision or the result of something else like not having a larger gauge wire size on hand at the last minute? For residential PV design, I was taught to keep voltage drop under 1% on the AC side and under 2% on the DC side. I've been trying to keep it around 1-2% on my bike (both charging and discharging) but 2-3 meters of of 10 AWG (5.3 mm^2) wire adds up to some significant weight.
justin_le said:
Well, this would seem to explain some of the unexpected behavior I've been seeing on long and/or steep descents like increase/decrease in braking power around the 45 kph mark and more/less regen amps than my max regen amps setting on the PR. When comparing to your example speeds, it helps that I'm using the same motor (Grin 5T DD), wheel size (20") and battery (36V). Maybe if I re-read the definition of back-emf for the 11th time it will eventually sink in...justin_le said:
Now I get why I saw ~40% regen on an extra-slow ride I took a few weeks back when the same hilly loop usually gets me 20-25%. I was descending the same hills at around 20 mph (32 kph) instead of the usual 30 mph (48 kph) or so. I knew the potential energy from the top to the bottom of the hill hadn't changed but it wasn't clear to me why I was getting so much more regen. (I also used less battery energy on the ascent.)
justin_le said:
Excellent. I've been struggling with this aspect of on-the-fly range estimation. Now that I have the GPS Analogger working with the solar firmware, I'll have to figure out my Wh per 100m number.
justin_le said:
So over 4% voltage drop? Was this a deliberate design decision or the result of something else like not having a larger gauge wire size on hand at the last minute? For residential PV design, I was taught to keep voltage drop under 1% on the AC side and under 2% on the DC side. I've been trying to keep it around 1-2% on my bike (both charging and discharging) but 2-3 meters of of 10 AWG (5.3 mm^2) wire adds up to some significant weight.
FredTheSwede
10 µW
- Joined
- Aug 5, 2017
- Messages
- 5
Great fun to read, my french in not so up to date so I have some teams I always check first before using translation services.
Thanks for the data will download in a second.
Is the data for others available somewhere, and should be default be handed out, or is it owned by each team or by the "Suntrip" team?
(Would be nice to run some scripts and compare designs with performance).
/Fred
before using translation services.Thanks for the data will download in a second.
Is the data for others available somewhere, and should be default be handed out, or is it owned by each team or by the "Suntrip" team?
(Would be nice to run some scripts and compare designs with performance).
/Fred
rachdatu
100 µW
Fantastic race. Congrat for the report and the data.
Good to know that you were in Switzerland, in Valais (flat valley) and then up to one of these "legendary" Swiss pass (Simplon pass).
Switzerland is a nice country to test ebikes, don't need to go far to find all kind of profiles.
A bit of tourism: https://www.valais.ch/en/touren/roa...ycling/simplon-pass-legendary-mountain-passes
By the way, I did not know you were speaking French as well. Next time I send you an email, you know in which language it will be
Walter
Good to know that you were in Switzerland, in Valais (flat valley) and then up to one of these "legendary" Swiss pass (Simplon pass).
Switzerland is a nice country to test ebikes, don't need to go far to find all kind of profiles.
A bit of tourism: https://www.valais.ch/en/touren/roa...ycling/simplon-pass-legendary-mountain-passes
By the way, I did not know you were speaking French as well. Next time I send you an email, you know in which language it will be
Walter
Hey Justin thanks for the updates! You said something that struck a chord for me -
When you are climbing a hill, a given throttle setting (on a torque-throttle setup) gives you a steady climb. If the bike sees a transient acceleration (i.e. you pedal or something) then it starts climbing faster. This requires more power (since you are increasing elevation at a faster rate) but torque hasn't changed - so you slow back down to the speed you were at before. Same thing happens if there's a transient slowdown - you speed back up to the speed you were at before.
At low speeds where drag isn't much of a factor this should be pretty simple to figure out - you climb at the speed where power = weight * (height/time.)
At first I thought going downhill with regen should be similar. After all, on my bike (as on most bikes) regen gives you a fixed torque resisting your descent - so you should descend at a constant speed, with regen "holding" you at that speed.
But what I found was the opposite. Because while the same formula holds (p=w*h/t) it's not stable. On a downhill, if you transiently speed up a little, then the "power" from the descent available (which is w*h/t) goes up - and the braking torque goes down as you describe. (same power, more RPM = less torque.) So you accelerate. Now you have more available power from gravity, since your h/t is going up, but braking torque is dropping, so you accelerate even more rapidly, until you hit the terminal velocity caused by increasing aero drag. When you transiently slow down a little, then the power available from gravity (w*h/t) goes down but braking torque goes UP, so you slow down even more. And you keep slowing down until you hit the limit of the regen, and then you creep down hill at some low regen point, usually a few kph.
One of the games I play during a long descent now is to try to find the magic point where the two (regen and descent 'power') balance out, both to maximize regen and for something to do. The one thing I don't like about this is it effectively requires me to 'pulse' the regen on and off (via the brake handle) to maintain this, and that's somewhat jarring. Someday I may find a two-way throttle (spring loaded return to 'zero' so you can twist one way for power, other for regen) so I have more control over regen, which would make the above a lot easier - and perhaps harvest a little more available power on a given descent.
An alternative, I guess, would be to have a speed-hold mode to keep you from exceeding X kph, and using regen to hold it there. Ironically one of my first ebikes (an EMS E+) did exactly that; when you were coasting downhill and the speed of the motor started exceeding base speed, the controller body diodes would start conducing power back to the battery and hold you at that speed. As I went to higher and higher battery voltages that stopped happening.
Thanks again for all the updates.
This is something I've noticed in my own riding, and it was very counter-intuitive to me at first.justin_le said:
When you are climbing a hill, a given throttle setting (on a torque-throttle setup) gives you a steady climb. If the bike sees a transient acceleration (i.e. you pedal or something) then it starts climbing faster. This requires more power (since you are increasing elevation at a faster rate) but torque hasn't changed - so you slow back down to the speed you were at before. Same thing happens if there's a transient slowdown - you speed back up to the speed you were at before.
At low speeds where drag isn't much of a factor this should be pretty simple to figure out - you climb at the speed where power = weight * (height/time.)
At first I thought going downhill with regen should be similar. After all, on my bike (as on most bikes) regen gives you a fixed torque resisting your descent - so you should descend at a constant speed, with regen "holding" you at that speed.
But what I found was the opposite. Because while the same formula holds (p=w*h/t) it's not stable. On a downhill, if you transiently speed up a little, then the "power" from the descent available (which is w*h/t) goes up - and the braking torque goes down as you describe. (same power, more RPM = less torque.) So you accelerate. Now you have more available power from gravity, since your h/t is going up, but braking torque is dropping, so you accelerate even more rapidly, until you hit the terminal velocity caused by increasing aero drag. When you transiently slow down a little, then the power available from gravity (w*h/t) goes down but braking torque goes UP, so you slow down even more. And you keep slowing down until you hit the limit of the regen, and then you creep down hill at some low regen point, usually a few kph.
One of the games I play during a long descent now is to try to find the magic point where the two (regen and descent 'power') balance out, both to maximize regen and for something to do. The one thing I don't like about this is it effectively requires me to 'pulse' the regen on and off (via the brake handle) to maintain this, and that's somewhat jarring. Someday I may find a two-way throttle (spring loaded return to 'zero' so you can twist one way for power, other for regen) so I have more control over regen, which would make the above a lot easier - and perhaps harvest a little more available power on a given descent.
An alternative, I guess, would be to have a speed-hold mode to keep you from exceeding X kph, and using regen to hold it there. Ironically one of my first ebikes (an EMS E+) did exactly that; when you were coasting downhill and the speed of the motor started exceeding base speed, the controller body diodes would start conducing power back to the battery and hold you at that speed. As I went to higher and higher battery voltages that stopped happening.
Thanks again for all the updates.
So if I understand you correctly -teklektik said:
Set up speed limiting and enable regen limiting. Control it via the AUX pot. When riding normally keep the pot all the way on (a limit of 60kph or something) and when descending dial it down until you are at the speed you want to descend at? I may try that; I have an aux pot connected but unassigned right now.
SprocketLocket
100 W
Justin, please be careful in your travels, and do not make the same mistake as this naive lefty couple who unfortunately proved another dogma of leftist culture wrong in the hardest way possible with (ironically and sadly) a "Darwin award". We want/need you around. From your carte, it looks like yous two will be going through similar or close-by areas, and there are many areas I would consider "No-go zones" (the existence of which was--until recently--denied by lefties, now no longer able to lie about it, with developments like Sweden now officially ceasing mail delivery to certain quarters, for the safety of their workers).
I know y'all are experienced travelers, but a Super Soaker filled with vinegar will be inadequate if insular, murderous Muslims (yep, I said it--been around it, it's real) decide to prove their anti-human value to the moon. I've been in more no-go zones than I'd like to delve into right now... and my best briefest advice regarding no-go zones is, simply, don't go.
Millennial Couple Bikes Near ISIS Territory to Prove ‘Humans Are Kind’ and Gets Killed
https://www.pluralist.com/posts/1824-millennial-couple-bikes-near-isis-territory-to-prove-humans-are-kind-and-gets-killed
Bleeding-Heart Liberals Bike Through Tajikistan to Prove “Evil Is a Make-Believe Concept” — Are Stabbed Dead By ISIS
https://www.thegatewaypundit.com/2018/08/bleeding-heart-liberals-bike-through-tajikistan-to-prove-evil-is-a-make-believe-concept-are-stabbed-dead-by-isis/
Can't help but draw the congruency.
I'll be really glad and relieved when you're both back safe and sound, and even some of my non-ebike friends will know and be happy too.
I'm not criticizing; your journey is epic... but we already knew you were epic. Just reminding (or begging--fine, I'll ditch pride) yous to defer to caution, and please trust that intuition and common sense that leftism teaches to go against [btdt]. ("The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." -quote from 1984 by George Orwell, which is an exposition of, and warning against, a leftist technocratic conspiracy truly being [strike]planned[/strike] exercised by elites. George Orwell split from that crew, which community included Aldous Huxley, who wrote Brave New World--which, unlike 1984, was not a warning, but an announcement; whose brother Julian founded the United Nations and UNESCO; and H.G. Wells, who, yes, wrote "The Time Machine", but have you ever been told he also wrote the book, "The New World Order"? Celebrating and inviting "international [globalist] socialism".) It IS time for everyone to awaken, get into that un-taught history, and reclaim common sense.
I know y'all are experienced travelers, but a Super Soaker filled with vinegar will be inadequate if insular, murderous Muslims (yep, I said it--been around it, it's real) decide to prove their anti-human value to the moon. I've been in more no-go zones than I'd like to delve into right now... and my best briefest advice regarding no-go zones is, simply, don't go.
Millennial Couple Bikes Near ISIS Territory to Prove ‘Humans Are Kind’ and Gets Killed
https://www.pluralist.com/posts/1824-millennial-couple-bikes-near-isis-territory-to-prove-humans-are-kind-and-gets-killed
Bleeding-Heart Liberals Bike Through Tajikistan to Prove “Evil Is a Make-Believe Concept” — Are Stabbed Dead By ISIS
https://www.thegatewaypundit.com/2018/08/bleeding-heart-liberals-bike-through-tajikistan-to-prove-evil-is-a-make-believe-concept-are-stabbed-dead-by-isis/
Can't help but draw the congruency.
I'll be really glad and relieved when you're both back safe and sound, and even some of my non-ebike friends will know and be happy too.
I'm not criticizing; your journey is epic... but we already knew you were epic. Just reminding (or begging--fine, I'll ditch pride) yous to defer to caution, and please trust that intuition and common sense that leftism teaches to go against [btdt]. ("The party told you to reject the evidence of your eyes and ears. It was their final, most essential command." -quote from 1984 by George Orwell, which is an exposition of, and warning against, a leftist technocratic conspiracy truly being [strike]planned[/strike] exercised by elites. George Orwell split from that crew, which community included Aldous Huxley, who wrote Brave New World--which, unlike 1984, was not a warning, but an announcement; whose brother Julian founded the United Nations and UNESCO; and H.G. Wells, who, yes, wrote "The Time Machine", but have you ever been told he also wrote the book, "The New World Order"? Celebrating and inviting "international [globalist] socialism".) It IS time for everyone to awaken, get into that un-taught history, and reclaim common sense.
wturber
1 MW
Was this really just an excuse to say "leftist" a lot? Your concern seems misplaced since they caught their flight out of Tehran many weeks ago.
I'm going to give Justin and An-So credit for probably making a reasonable evaluation of the risks involved in the trip. I seem to recall some mention about areas that were off-limits for different reasons. For my part, I figure the risks of getting run over by some careless motorist who wasn't paying attention were probably far greater than the (very real) risks of being victimized by a terrorist or other criminal type who was up to no good.
Fact is that the vast majority of people are kind and benevolent - given half a chance. But that truth doesn't mean that there aren't still a small number people who are quite the opposite. So yes, you should probably try to avoid them. Unfortunately it is often hard to know where they are and who they are.
http://www.dailymail.co.uk/news/art...t-death-road-rage-attack-getting-runover.html
I'm going to give Justin and An-So credit for probably making a reasonable evaluation of the risks involved in the trip. I seem to recall some mention about areas that were off-limits for different reasons. For my part, I figure the risks of getting run over by some careless motorist who wasn't paying attention were probably far greater than the (very real) risks of being victimized by a terrorist or other criminal type who was up to no good.
Fact is that the vast majority of people are kind and benevolent - given half a chance. But that truth doesn't mean that there aren't still a small number people who are quite the opposite. So yes, you should probably try to avoid them. Unfortunately it is often hard to know where they are and who they are.
http://www.dailymail.co.uk/news/art...t-death-road-rage-attack-getting-runover.html
solarEbike
100 W
teklektik said:
I'm finalizing the wiring on my solar ebike so I'm at a point where I have to address this issue. I've wired an on/off switch to the Phaserunner but need to keep the CA3 powered on anytime the bike is charging from solar which includes leaving it on overnight to record early morning charge current for those days when I don't get up before dawn.
Can I just run the CA-DP Plug's red V+ wire to the battery through a switch? Is there a way to turn off the CA3 backlight?
Yep - just switch the CA to Vbatt+ and you're all set. I wire my bikes this way - the switch also powers the lighting DC converter and there's a kill switch on the throttle to turn off the controller. This keeps the lights working and the CA instrumentation alive regardless of whether the controller is ON. Lets you switch off a sick controller and pedal on with everything otherwise working normally.solarEbike said:
There's presently no means to switch off the backlight but a switch and minor electrical component could be added easily enough - there's enough room on the bottom or side of the CA case. The backlight actually plays a necessary role in the 5V regulator circuit so it's a matter of switching in an alternate component. I don't know the needed voltage drop off the top of my head but let me know if you want to pursue this and I'll post up something.
solarEbike
100 W
teklektik said:
Thanks for the confirmation. I have an unused switch next to the throttle and now that you mention it, it's a good location for the controller switch.
I'm using a separate (3rd) switch for the 12V DC converter for lighting and accessories so I can cut the parasitic drain while keeping the CA powered. I tried using one of these lighted switches for that but it failed closed in less than three months. The autopsy revealed heavily pitted contacts. I guess it's arcing due to inrush current on the converter. I think I'll just replace it with a beefy toggle switch but that's just kicking the can down the road. I've read up on adding soft start circuits to mitigate this but that sounds like more work than I have time for right now. I'll let future me judge the wisdom of that decision.
teklektik said:
I've noticed that brightness of the backlight is occasionally mentioned during troubleshooting so I had a feeling you might say something like that. I think I'm going to leave the backlight alone for now so please don't go to any extra effort unless others express an interest.
The conspicuousness of the backlight at night was one reason for asking. I guess I can just cover it for now if I feel the need. The other reason was suspected current drain which I just measured to be 50 mA at 41.5V for my CA3 with backlight on and Sempu BB plugged in. The Sempu accounts for 40 mA of that which got me thinking that I'm losing 20-30 Wh per day in standby losses if it's left on for 16-20 hours per day when I'm not riding. But after re-reading this post I confirmed that the Sempu goes into sleep mode after 10 minutes and draws less than 10 mA.
I'm finding that quiescent current draws which are inconsequential for daily commuting with AC charging can add up to several miles lost per day when trying to cover a lot of distance on solar power. I see a lot more switches in my future...
Actually, on one of my bikes I switch a big converter with a 40A 48V relay to avoid the inrush issue. Annoying and eats power. The other uses a very much smaller converter for LED lighting that doesn't have the inrush issue of the big moose one and so gets the simple switch treatment.solarEbike said:
Yep - figured as much. Blanking the screen so it looks OFF in daylight is simple, but the backlight thing is not so easily twiddled. I have to add that there is also a red backlight option in there already that can be made electrically switchable if you want to go after a whole extravaganza of nighttime options....solarEbike said: