Search found 183 matches

by solarEbike
Jun 18 2020 12:41pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

Final assembly of the trailer panels is proceeding apace. Tab wires and Kapton tape on the back of the panel for bypass diodes. 48D9EA8A-8DC0-4616-839C-5AEF317DF177.jpg Epoxy potting compound candy-coating to keep them dry. This stuff takes 4 days to fully cure at room temperature or two hours at ov...
by solarEbike
Jun 06 2020 11:43pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

I wasn't expecting this much trouble with wind because the previous single wheel trailer (almost) never had this problem. This version is 26% lighter, has 7% more surface area, tilts to 85° from horizontal instead of 45°and is a little higher off the ground for more suspension travel. Each of these ...
by solarEbike
Jun 06 2020 11:54am
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

Right after completing my 139 mile trip, I started planning what will hopefully be my first double century ride (200 miles, "triple metric century+"??). The target date is June 20, given or take a couple of days so I can cherry-pick optimal weather conditions. Not only is it another bucket...
by solarEbike
May 21 2020 1:44pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

I think I solved the mystery of why the bypass diodes appear to work intermittently. It has more to do with the very low breakdown voltage of SunPower cells and the way they interact with the Genasun MPP tracking algorithm. I got similar results with a conventional bypass diode and the Texas Instrum...
by solarEbike
May 19 2020 10:52pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

john61ct wrote:
May 19 2020 10:06pm
Solution for partial shade impact mitigation:

one SC per panel, full stop.
I already have 3 solar charge controllers for 4 panels. As soon as one or two cells are shaded, I lose the whole panel. This is a way to get back 30-140 watts.
by solarEbike
May 19 2020 10:43pm
Forum: Alternative Energy
Topic: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery
Replies: 15
Views: 1378

Re: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery

But these particular panels aren't really worth the weight of carrying them on the trike (at least, not the generic (possibly harbor-freight) ones, that I have three of). Definitely not. Thin film is around half the efficiency of traditional crystalline silicon so twice the surface are and twice th...
by solarEbike
May 19 2020 9:47pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

Fast forward to today and we have "active diode" or "smart diode" devices like this Texas Instruments SM74611. It's not small enough to encapsulate within the cell but the cost ($3-4), forward voltage (26 mV) and reverse leakage current (3 µA) make it feasible to put one for eve...
by solarEbike
May 18 2020 10:38am
Forum: Alternative Energy
Topic: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery
Replies: 15
Views: 1378

Re: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery

Hope you feel better soon. Upon further reflection, it occurred to me that my explanation makes it difficult to see the bigger picture. This chart might help make it clearer why the voltage range of these (or any other) solar panels is unsuitable for direct connection to a lithium battery. The Vmp i...
by solarEbike
May 16 2020 4:36pm
Forum: Alternative Energy
Topic: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery
Replies: 15
Views: 1378

Re: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery

PS: A 250 watt solar panel in Phoenix, Arizona with 90% charge controller efficiency and 10% shading losses would average the following watt-hours per day. ( source ) Phoenix-250w-panel.png You guys get some serious sun. There's a reason the U.S. Global Horizontal Irradiance map looks like this: US-...
by solarEbike
May 16 2020 1:11pm
Forum: Alternative Energy
Topic: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery
Replies: 15
Views: 1378

Re: MPPT (or whatever) to use 4 series small panels as "charger" for 14s EIG NMC battery

Maximum Power Pmax 15w +/-5w ... (unreadable) AM1.5.10000W/M2 It's +/- 5 % (+/-5W would be huge on a 15W panel). The unreadable part is "Standard Test Conditions" or STC and refers to the conditions at which all the voltage and current are measured. They're temperature and irradiance depe...
by solarEbike
May 11 2020 12:53pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

...including this one short stretch which was paved with carpet remnants (seriously?) Carpet remnants, if large enough, are MUCH better than mud... I figured it was something like that. It was just so unexpected to find in the middle of nowhere. One moment I'm on a paved bike path and suddenly it's...
by solarEbike
May 07 2020 5:44pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

I'll be building a cargo trike - tadpole configuration. Ideally I'd like to have a removable awning framework to support solar panels for recharging either while riding or when parked for when I'm using the trike for extended trips. Most of the around town trips can be covered by my current battery...
by solarEbike
May 07 2020 3:52pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Love in the Time of Cholera or Solar Touring in the Time of Coronavirus

Coronavirus Diary. Week 8 of lockdown. Cabin fever. Riding about 150 miles (240 km) per week but getting bored with the same loop over and over again. Outdoor exercise, including bike riding, is permitted in the SF Bay Area but non-essential travel is not. Scouring Google Maps for fresh ideas, I spo...
by solarEbike
Apr 15 2020 4:55pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

In my opinion your panels that you will use on your trip are perfectly fine at the moment. Agreed. I'm a little disappointed because I had expected slightly higher output. I'll need to add module degradation as a factor in my solar production modeling and route planning but I don't expect it to pla...
by solarEbike
Apr 15 2020 3:42pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

It explains exactly what I've seen happen to a number of panels mounted to the front of my recumbent over the years. I've just usually upgraded to a bigger panel before it got too bad each time, although I did have one panel drop to <3W which was rendered useless. So what is the solution? Can we bu...
by solarEbike
Apr 14 2020 6:06pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

U assume that Covid-19 destroyed your trip so far :-( Have you already been on the road? I'm stuck in Oakland, trying to focus on the positive aspects of not having to deal with the pandemic while traveling. The trip is on hold for now but my intention is to go ahead when it becomes feasible. In th...
by solarEbike
Nov 30 2019 5:32pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

Best way to analyse this now would be to make IR photographs of the used modules. Or fully calibrated power measurements with irradiance and cell temperature, taken before and after the race but that's not likely to happen either. It would also eliminate errors in reported panel output ratings. Raf...
by solarEbike
Nov 30 2019 4:42pm
Forum: EBike Build Threads
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 342
Views: 65881

Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

This website offers plenty of information about winning long distance races: https://ridefar.info/ Okay, we are talking about 10 days vs 45 days, but still the 250km/day don't look so impressive any more. Great resource, thanks. I look forward to reading more of it. If we're looking for ultra long ...
by solarEbike
Nov 29 2019 6:40pm
Forum: EBike Build Threads
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 342
Views: 65881

Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Thanks for the analysis. This provides a stark contrast to my much higher Wh/mi consumption in my city e-bike commuting. Same here. It took me a long time to figure out what kind of Wh/mi to expect for solar touring. It's different from everyday local riding where a bigger battery will easily solve...
by solarEbike
Nov 28 2019 5:15pm
Forum: EBike Build Threads
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 342
Views: 65881

Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

My last post offered some conclusions about building a solar bike for casual touring but what does the data say about strategies for winning The Sun Trip 2020 ? Max out your solar array For single riders, the 2018 rules allowed up to 450 solar watts deployed while riding. The 2020 rules no longer sp...
by solarEbike
Nov 27 2019 5:17pm
Forum: EBike Build Threads
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 342
Views: 65881

Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

There must be an abundance of data form all those data Loggers. I was interested in exploring the data to see what guidance it may contain for selecting solar panel size and tilting vs. non-tilting mounting design choices for casual solar bike touring. Here's what I found: Screen Shot 2019-11-27 at...
by solarEbike
Nov 26 2019 10:27pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

Here is maximum output of Jack Butlers solar array... I don't know, but I assume that the solar panels Jack Butler used did have significant performance problems at the end. When searching for a picture of the mounting of his solar panels I noticed that he crashed his bike. Interesting idea to look...
by solarEbike
Nov 25 2019 1:29pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

IR Pictures can be made easy and cheap with a dark room, a suitable DC power source to reverse power the solar module (bypass any diodes) and an old Sony F717 or Sony F828 with s small magnet to put it into "nightshot" mode. This is great. Thanks for sharing. I remember we talked about th...
by solarEbike
Nov 24 2019 10:25pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

I don't just randomly buy cheap solar panels from eBay hoping for the best. I look for domestic importers/manufacturers that use eBay as another store front and have a review history online. Mine was at about $1 per watt. I also did my research and still ended up with some good panels and a couple ...
by solarEbike
Nov 24 2019 4:55pm
Forum: EBike Build Threads
Topic: Around the world on a solar ebike
Replies: 326
Views: 56476

Re: Around the world on a solar ebike

<sarcasm> OTOH, ebay seems to be the place where you can find the most high tech of 18650 cells. One need not look far to find 18650 cells that have 6800, 7900, and even 9900mah capacities. So clearly ebay must offer the leading edge of high tech componentry</sarcasm> I buy plenty from ebay. And th...