Cycle Analyst 2.0 - Happy Host

[knightmb]

100mile ride!!! there would have been a lot of peddling without the motor i'm guessing? or did you use the motor the whole time?

Combination. But I was only doing the "pack" speed, which for these long rides are like 15 to 20MPH tops. I was drafting a group of like 40 people, so it's amazing how little energy it takes to move the bike when there is no wind resistance, hehe. I wish I had a drain brain during those times though. The ride takes about 5 hours or more, which is in line for about a 100 watt ride on the batteries which after my discharge test, they handle this just fine. When I do a free wheel spin, I'm burning about 90 watts and it takes about 5 1/2 hours to discharge the pack.

But.... today I had to chance to see how much draft can help. I got behind a large truck that was only doing 30 mph for a 2 mile level stretch of road. So I drafted the truck big time. The CA only showed 200 watts for 30MPH, and that was with normal pedal effort by myself at the same time. So I can see why these last for 100 miles when I'm only doing 15 to 20MPH and I have a large group of riders in front to break the wind resistance.

 

[knightmb]

Here are some pictures from past events.

A lot of people ride the tour Tour de Nash, getting more every year
Remember that game of "Where's Waldo", how about "Where's Knight?", LOL.
These are old pictures from 2005, 2006. So far, I've done the ride every year for 2004, 2005, 2006, and 2007 this year.

 

[justin_le]

My only concern was that you have to remember to reset your CA before it reaches 199.9 otherwise your total distance won't increment properly. I can live with a 199.9 trip limitation.

Seems he should be able to separate the tripometer count function from the odometer count function without adding memory or processor, or removing digits -- but I don't know much about digital processing.

Well right now, the tripometer is accurate because it's calculating out to the 0.001 decimal place. 1 mile being 5280 feet, so every 1 decimal place is 5.28 feet. On the flip side, 1 km being 1 meter per digit. So if he cuts out the thousand place, to move it over to a bigger 2000+ number, the accuracy gets chopped down to .01 in which case that's 52.8 feet or 10 meters per digit of accuracy. In the grand scheme of things, 52 feet or 10 meters might not make a big impact on accuracy for a 30 mile or 50 km trip. It would for a short trip though.

Wow, what a lively discusssion resulting from some tough programming decisions made a while back! The actual reason for the 199 limit on trip distance was a tradeoff between low speed accuracy and total expected distance travelled. In the original design the unit calculates distance by integrating the speed over a 10mS time period. In 10mS, a vehicle doesn't travel very far, so even though the display resolution is to the nearest 1 meter, the internal distance is recorded to the nearest 0.1mm. 0.1 mm times a signed 32 bit number gives a maximum of 214.7483648 km before the number overflows. If instead the distance was stored to the nearest 1mm, then the overflow wouldn't happen until 2000 km. But at very low speeds you are only travelling a few mm in that 10mS time loop, and so roundoff errors from repeatedly adding say 9mm instead of 9.7mm could become significant.

<p> In any case, there are several ways I could do work arounds in the code so that there is no such cap on the trip distance and given the feedback here it sounds like this ought to be a priority. The trip distance is only added to the odometer distance counter after a reset. The two counter values are added together before being shown on the display, which is why the odometer would appear to stop incrementing as well.

Also, I would expect people to generally hit the 1999 watt-hour limit before the distance limit. This will make the the wh/km or wh/mi readings inaccurate. Few PEV's have more than 2KWh of battery capacity, so if the unit is reset after each charge as it was designed then this is not an issue. But it will cause problems if you want to run for days or weeks at a time to get a long period average of the vehicle performance. So keep that in mind.

The microchip used in the CycleAnalyst has more code and memory space than the DrainBrain, so I should be able to get rid of these trip accumulator limits in the next version release.

-Justin (still working on the CA manual, it's coming soon I promise)

 

[xyster]

Also, I would expect people to generally hit the 1999 watt-hour limit before the distance limit. This will make the the wh/km or wh/mi readings inaccurate. Few PEV's have more than 2KWh of battery capacity, so if the unit is reset after each charge as it was designed then this is not an issue. But it will cause problems if you want to run for days or weeks at a time to get a long period average of the vehicle performance. So keep that in mind.

Thank you, Justin, for the explan and your continued dedication to improving this unique product. I use a 2,500 watt-hour pack. So far as I know, it's the highest capacity pack here. My range at normal bicycle speeds is over 120 miles. Over time though, there's bound to be more large packs, particularly for distance riders pulling a trailer, and as fuel cell/chemical battery hybrid packs become affordable.

 

[TylerDurden]

In any case, there are several ways I could do work arounds in the code so that there is no such cap on the trip distance and given the feedback here it sounds like this ought to be a priority. The trip distance is only added to the odometer distance counter after a reset. The two counter values are added together before being shown on the display, which is why the odometer would appear to stop incrementing as well.

Excellent.

Lazy people like myself will neglect to read the operating instructions or reset the tripmeter... then complain about the odometer stopping.

:?

 

[knightmb]

Well to make this topic even more picture filled than it is.

Did a battery bash test this morning. Fully charged batteries, took the bike out on the highway (but not the kind that had 70+ MPH speed limits, we call that the Interstate here :wink: ) I did a full throttle non-stop (with an occasional stop light) run on the batteries until they finally hit 40 volts for the 48 volt pack. Going up and down hills, as fast as they could take me. There was also this bad headwind, but I figured it good because it was helping to keep the watt meter maxed all the time
I did sorta pedal at one stop light because I was racing a dump truck, but afterwards, it was just some pretend pedal, casual pedaling.

I was surprised to find that I've gained AH capacity since my last full drain test? It doesn't make sense why at full throttle I would get better capacity that just having the wheel sit off the ground and spin, but who am I to argue. Maybe I'm getting a better charge into the batteries since I can tell with more accuracy of "when" they need to be charged.

On a side note, after they were discharged, I could still limp home at 200 watts of power without dropping the voltage below 40, so even at a nearly full discharge I can maintain an easy 15 mph.

 

[justin_le]

I use a 2,500 watt-hour pack. So far as I know, it's the highest capacity pack here. My range at normal bicycle speeds is over 120 miles. Over time though, there's bound to be more large packs, particularly for distance riders pulling a trailer, and as fuel cell/chemical battery hybrid packs become affordable.

2,500 watt-hours, wow talk about not needing to be easy on the throttle. With the present version if you have a shunt resistance that is less than 1mOhm then you can setup the unit for High Range mode which extends the total watt hours to 20,000. So for the higher power rigs using a remote shunt a much larger capacity battery can be accomodated, but with the stock 1.4mOhm shunts it's capped to 2kWh.

In any case though I'll make raising the trip watt-hours and trip distance caps a priority for Version 2.1

While we're at it, is anyone here approaching the 199 Amp-hour limit?

I did get rid of the 99 speed cap from before so now it's good up to 655.36 km or mi/hr. I think ebikes are still a long way from pushing this boundary! Then again I thought 99 kph was plenty enough until Lowell came along...

Justin

 

[xyster]

I use a 2,500 watt-hour pack. So far as I know, it's the highest capacity pack here. My range at normal bicycle speeds is over 120 miles. Over time though, there's bound to be more large packs, particularly for distance riders pulling a trailer, and as fuel cell/chemical battery hybrid packs become affordable.

2,500 watt-hours, wow talk about not needing to be easy on the throttle.

300, 2.2ah lithium 18650s to go with that most-excellent, amp-happy 5304 you sold me.

In any case though I'll make raising the trip watt-hours and trip distance caps a priority for Version 2.1

Thanks! I'll get one one of these days. Waiting has its advantages when the developer keeps improving the product so fast.

While we're at it, is anyone here approaching the 199 Amp-hour limit?

LOL. I don't think so. Mine is 33ah, some people here use SLA packs in the 30-40ah range. That's the highest I'm presently aware of.

I did get rid of the 99 speed cap from before so now it's good up to 655.36 km or mi/hr. I think ebikes are still a long way from pushing this boundary! Then again I thought 99 kph was plenty enough until Lowell came along...

Justin

LOL. Now that he knows the new limit is 655.36 kph/mph, I expect Lowell will post a video from the Salt Flats testing that.