My 102 Miles Ebike Racing Experience

[Evoforce]

Good to see Lyen and Mrbill participate in this challenge. Congratulations on finishing! Hope you didn't destroy too much money in the process. Cool!

 

[liveforphysics]

Ahh yes, the joys of racing. Damaged parts. I was fully expecting to see some puffy-pack pics from over-discharge.
That's how it goes.
Get some of the "goop" brand glue, pop the foil somewhere with a pin, squeeze the pack snug in a vise (between some boards or books or something) to get as much air out as you can, then goop over the hole.

The solvent that has off-gassed can't help the cell anymore by being in there, and if the cell layers aren't tight enough to contact firmly, then they can't function well (resistance goes to crap), so pricking them and sealing them back up is the the only practical option at this point.

KiM (AussieJester) was bold enough to pioneer the technique, and I think about 10 folks, including myself (just to experiment) have done it since then with good results.

Obviously not something anyone wants to have to do, but giving it a shot is better than throwing it out.

 

[Lyen]

Thanks for complimenting me on my race experience guys!

I believe the way to win the race is to know your competitors, the road, your ability, practicing, as well as good preparation.

Luke and Aaron and Ryan and Chroot, MrBill actuall post about the Mega-Monster Enduro event a while ago here.
http://endless-sphere.com/forums/viewtopic.php?f=25&t=23768
But I will let you guys know just in case next time. I have heard from MrBill that there will be a hill climbs challenge in October.

LI-ghtcycle, my average speed is theroically around 21mph. However, I have stopped twice to help out two guys with flat tires. One guy got a flat tire on his tubular wheel right before the second checkpoint. Another person's bike got something pinched through his carbon rim from the sidewall of his tire.

Doctorbass, 12-13Wh per km is around .62 mile or 19-20 watt hours per mile which is very efficient. I managed only around 15 watts hour per mile or 9.43whr per km due to lots of head wind.

John in CR, MrBill said the maximum allowable battery is 2000 watt. I thought I brought enough but the RC charger lied to me and indicated it was fully charged when it was not. I confirmed this by using the Hyperion charger which is more accurate measursing the available capacity. I have learned it the hard way and forced me to pedal one third of the course on my way back.

Dogman, yes it was fun. I believe the death race needs a completely different type of bike and optimization. 2000 watts can only last 50 miles without pedaling at speed of 30mph. I have testified this locally.

Torker, I totally agree with you that recumbent does have its aerodynamic advatanges. But the ebike that MrBill brought is quite heavy that it really takes two person to transport it in and out from his car.

Number1cruncher, yes I do just like Methods. I'm an engineering level III at the US's third largest wireless carrier since 1999. Brewing controllers do really takes up time. I studied electronics at John O'Connell in San Francisco back in 1984. I may have to quite my job to keep it up. My extra bottle was already in used. LOL

Grindz145, Bill used the custom Valence LifePO4 battery. His cells are very unique because each lifepo4 cell is 12v each. He said they can run as low as 5v. He told me his overall power usage is around 1400-1500w only.

Rassy, 64 miles used up only 850Whr is very impressive. Were you riding on your electric trike? I actually had to ride behind other riders to learn how they attack hills and hyper extend the range.

Bzhwindtalker, I did not realize you can overcharge lipo cells. How far can you overcharge the lipo if you do not mind I ask? I have seen the Velomobile on the web. It is very nice looking.

Kingfish, what kind of bike were you using for the century ride? I was thinking of using a road bike instead of a hybrid but did not have the resource to set one up.

Evoforce, I have to admit I suck on taking care of batteries. The good thing is the more I damaged the cells the more I learned from the expensive lessons.

Luke, yes damages are to be expected. I had to overhaul and relube my drivetrain including the planetary gear assembly, sprockets, and chains. Thanks for the idea of getting the gas out of the packs and "Goop" them back. I will test out the differences in capacity prior I execute it.

Seriously, most of the lycra guys without motors are capable of the speed like him:
[youtube]1a_Z-ywTc4w[/youtube]

 

[Kingfish]

...
Kingfish, what kind of bike were you using for the century ride? I was thinking of using a road bike instead of a hybrid but did not have the resource to set one up.

WOW! Great vid

If there are racing constraints as stipulated then an augmented electric using the lightest bike frame with a streamlined rider would likely be the best, however it can be afforded. All my past centuries were accomplished on the “P0” 1991 Specialized Rockhopper with RS-1 RockShox (hardtail). I have yet to perform a century on the current “P1” full-suspension bike frame; it is in a constant state of upgrade-evolution, morphing into a light motorcycle with pedals. At higher speeds, things like tire balance & wear, as well as quality of ride (suspension) and visual-safety (moving in traffic) magnify in importance.

Luke, the puffed battery solution is encouraging; after 16 months, 6 of my 36 are puffed out – not terribly bad, though enough that I’ve taken them out of service. I’m pretty much resolved to not allow the charge to drop below 3.5V/cell; don’t drain the pack to LVC.

Sprinting, KF

 

[chroot]

Look like fake video! No one able accelerating that fast.

 

[bzhwindtalker]

I think LFP is the expert in overcharged lipos here, he got 1/5 more energy than a 4.2v charge by getting them to 4.5v if I recall?

 

[Rassy]

64 miles used up only 850Whr is very impressive. Were you riding on your electric trike?

Yes, it was on the trike currently in my Avatar. But the battery usage isn't too impressive when you consider the slow speed, probably averaging about 10 MPH. One thing I need to do to improve performance is to upgrade my tires. I'm still running the original 40 PSI tires. My pedal only buddy I ride with has 90 PSI tires on his trike and he zooms (his is a TerraTrike Zoomer) ahead of me when we coast down hills.

 

[liveforphysics]

I think LFP is the expert in overcharged lipos here, he got 1/5 more energy than a 4.2v charge by getting them to 4.5v if I recall?

You get 1/5th (1Ah in a 5Ah cell) from going from 4.2v to 4.35v (and seems to have no risk of flame event, but should be taking many 10's of cycles of life out of the cells).

You get a shocking 2.5Ah more (50% increase!) from going from 4.2 to 4.5v. However, all older generation LiPo cells explode right around 4.5v or less. The modern HobbyCity cells generally can handle up to ~5.1-5.2v before blowing (they are damaged before this point, but seldom explode).


Do not try this unless you are willing to risk the pack exploding into flames. Anytime you go over 4.2, you're rolling the dice if you're using an older LiPo formula.
Using good modern LiPo, going to 4.35v has never caused any ill results in my experience, and going to 4.5v is ok most of the time... but only try this at your own risk, and realize you may destroy your pack/bike/etc, and it WILL cost your pack many life cycles.
So, for an occasional race, hey, it's worth an extra 20-30miles of range in a 100mile race, that's worth losing some life off the pack IMHO.

If you're using an unknown quality/brand of LiPo cell, before you put your whole pack at risk, do some test cycles on a single cell to make sure it behaves itself, and make sure you're cell really gives back the capacity to make it worth it.

 

[Doctorbass]

I think LFP is the expert in overcharged lipos here, he got 1/5 more energy than a 4.2v charge by getting them to 4.5v if I recall?

You get 1/5th (1Ah in a 5Ah cell) from going from 4.2v to 4.35v (and seems to have no risk of flame event, but should be taking many 10's of cycles of life out of the cells).

You get a shocking 2.5Ah more (50% increase!) from going from 4.2 to 4.5v. However, all older generation LiPo cells explode right around 4.5v or less. The modern HobbyCity cells generally can handle up to ~5.1-5.2v before blowing (they are damaged before this point, but seldom explode).


Do not try this unless you are willing to risk the pack exploding into flames. Anytime you go over 4.2, you're rolling the dice if you're using an older LiPo formula.
Using good modern LiPo, going to 4.35v has never caused any ill results in my experience, and going to 4.5v is ok most of the time... but only try this at your own risk, and realize you may destroy your pack/bike/etc, and it WILL cost your pack many life cycles.
So, for an occasional race, hey, it's worth an extra 20-30miles of range in a 100mile race, that's worth losing some life off the pack IMHO.

If you're using an unknown quality/brand of LiPo cell, before you put your whole pack at risk, do some test cycles on a single cell to make sure it behaves itself, and make sure you're cell really gives back the capacity to make it worth it.

LFP, Two years ago with my mongoose and Konion cells I had an issue to 4.5V per cells.

I brang my charger to a friend that i combined with couples of 5V 30A Dc DC in serie to rise the voltage 15 more volts for his ebike from 50.4V to 65V.

We did a long ride and when came the moment to charge our battery, when it was my turn to charge my ebike battery, i forgot to remove the dc-dc..

When i wanted to check the Ah charged on my ebike, i realized that voltage was at 54V instead of 50.4 max !

Battery was normal temp.. But i immediatly disconnected the charger. I hcecked the cells boltage and surprizingly they was all still balanced to +/-20mV !!

I decided to go for a ride and to remove this exces of charge ( i thought that what could damage the cell more would be to leave them at this level more time)

I remember that to bring all the cells back to normal voltage of 100.8V ( 2 x 50.4V) It took like 3Ah out of 20Ah i had for the pack

Controller never bown eventhou it was using the 4110..

But battery suffered a bit... but not immediatly...

The fact is that they lost capacity and Ri rised alot over the two next years

Today the Ri doubled ! from 3miliohm for a 1s18p to 6 miliohm.

Capacity is around 17Ah now. ( but i must specify that this pack is made of recycled used makita pack and now have 300 cycles i added to them from when i got them...

But... that ride at 4.5V per cell was... AMAZING !!.. it was like a big Boost!

 

[hydro-one]

I just took 12 packs of 5s5000mah turnigy up to 4.5v per cell, and can happliy report NO FIRE!!!!! . I accidentally plugged my pack on the "boost" meanwell (set to 67.5v for slamming amps at end of charge (usually run with cellog on one pack). I have another charger set to 62.5 which is 4.15v per cell (15s). oops wrong meanwell. went for a ride and seemed to have great power and range. Have not checked pack for swelling (edit : no swelling)or unbalance (still in balance) will report back when i do. have around 700-1000 deep cycles on them already in 1.5 years.
just got busted $300 fines , no transport canada sticker, 45km on sidewalk, busy city, cops followed behind, i was in blissful disregard for them being there, oops, said they take bike next time, i will burn tix in video for you all.
mike

 

[Alan B]

Happy New Year. Only a month and a half to the next one of these races? (actually a bit less...)

http://megamonster.lowkeyhillclimbs.com/2012/

My Greyborg will probably not be ready.