How many miles on your Lipo??

[dannyboyohyeah]

I'm just curious. Who'se gotten the most miles on their Lipo setup? What's the size of your pack? What are your riding conditions? I'm more curious about overall lifespan in miles, than how many charge cycles. Once we know you're one've the winners...then maybe we can pick your brain about how you did it. Dollars to miles, I'd like to learn about efficiency of different set-ups.

 

[NeilP]

http://endless-sphere.com/forums/viewtopic.php?f=14&t=37189

 

[dannyboyohyeah]

Yes,,,,,that's a very good thread, Neil...and seems to make my question too simplistic, or assuming that everyone's cells arrive perfect and stayed in balance. Of course that is not the case. I just happen to be about 160 cycles into my first pack and everything is still up and balancing well. If and when I get a rogue, it will be a real bummer because of how to fix it means old and new. So I guess there's an element of luck in getting solid cells that last equally. Hopefully, this thread might reveal the longevity of "repaired packs", in relation to packs that miraculously stayed in balance. And....by "repaired packs", I mean a pack that already has had some significant lifespan, rather than a pack that has been troubleshot and repaired at the outset.

 

[Ykick]

For repairing bricks the calendar doesn't matter as much as cell IR (internal resistance).

Learn how to test cell IR and use similar values when replacing.

As far as your Q, I'm over 10k miles on majority of 20C Turnigy bricks. But that didn't happen without repairs along the way.

 

[NeilP]

Well my packs was 20s4p nanotech 5Ah made from 8 sticks of 10s

8452 miles when I stopped using it as it was getting puffy even fter repairs, with the last 500 miles or so running at 3parallel.

My fault that I had to go from 4p to 3p ..I let cells get to far out of balance..and was charging a few cells to 4.3 That set then went to zero volts, I did not notice, so I was charging what was effectively now a 19s pack to 83 volts calc. so each remaining cell lock was going to 4.35

 

[dannyboyohyeah]

I only have 3100 miles on my first and only pack. The majority of those miles was in California, where I had a 20 mile commute (sort've brutal). 15s 4p for that.
Here, I have zero commute but ride often. Reduced the pack to 3p, and so have these spare cells that I keep similarly aged by rotating in the pack, so that future repairs will be more balanced in terms of IR, etc. I naively assume so. But the thrust of my question is about perhaps an unexplored efficiency of various pack builds in terms of lifespan in miles used.

 

[dannyboyohyeah]

Neil~ That's one heck of a pack. Long commute? Where did you put it on the bike?

 

[recumbent]

Three years (8,000 km) 6,000 miles of daily bulk charging lipo's, and only 30 milli amps deviation is the worst cell from a 14 series 3 parallel pack which is still holding up fairly well.
But rarely charge over 4.1 Volts, and never go below 3.7 volts, and check weekly with Celllog, they stay amazingly balanced.

edit: oops I meant 030 milli-volts.

 

[dannyboyohyeah]

regardless of whatever motor you use or speed to like to travel at, I have always assumed that the most important thing to longevity lies in the % of overbuild you have in reserve, before LVC on your typical commute. This assumption may or may not be at all valid. I just always felt that the closer one gets to LVC, the more perilous for overall life of the batts. This complicates the initial question maybe, but it's part of the point of what I want to learn about. Some people may never discharge more than 50% before recharging....I don't know. Others, by necessity of their commute, may dance along the edges of LVC and get away with it. This I also do not know, but a better than average lifespan is what I want to learn about.

 

[dannyboyohyeah]

Recumbent~~
thanks. How often do you balance-charge??

 

[NeilP]

% of overbuild you have in reserve, before LVC on your typical commute. This assumption may or may not be at all valid. I just always felt that the closer one gets to LVC, the more perilous for overall life of the batts.

Neil~ That's one heck of a pack. Long commute? Where did you put it on the bike?

16 mile round trip..so not that long..but with my job, I wanted to have enough capacity to get to work, get home, then have enough capacity to get back to work with no need to re charge.....I fly the local air ambulance, so have to be prepared to get back to airport quickly. if I am flat out to work, 35-45 mph, I can do the 8 miles in a little under 14 minutes, using 6 Ah or so.
if I keep speed low..20-25mph and pedal a bit I can get 50 miles per charge.

pack is in frame triangle

 

[kriskros]

1700 miles..had to replace one brick...8x6s/5000mah..turnigy...still going...done almost 600miles since repair

 

[recumbent]

Recumbent~~
thanks. How often do you balance-charge??

Twice in three years, but didn't need to, I followed the hype back then when we thought we have to keep it balanced tight, which is not true. .020 Milli-Volts difference is no big deal if you don't drain the pack lower than 3.7 volts each. just set your LVC.
However, it 's good practice to monitor your cells carefully if you bulk charge like many of us do.

 

[zombiess]

Recumbent~~
thanks. How often do you balance-charge??

Twice in three years, but didn't need to, I followed the hype back then when we thought we have to keep it balanced tight, which is not true. .020 Milli-Volts difference is no big deal if you don't drain the pack lower than 3.7 volts each. just set your LVC.
However, it 's good practice to monitor your cells carefully if you bulk charge like many of us do.

I'm not trying to nit pick on you, I just wanted to help you out with your units since you seem to be mixing them up.

0.002 V = 2 mV
0.020 V = 20mV

0.020mV = 0.00002 V... this is 20 uV (micro volts)

Thanks for posting your stats.

 

[dogman dan]

I never tracked miles, and only estimated cycles. But I was storing my lipo the worst way. Fully charged and ready to go. I got two years of use with decent capacity, then the last year was at quickly decreasing capacity. This was true of both 30c packs used a lot, and some 20c stuff rarely actually used. This taught me to stop storing all my packs fully charged.

The very first packs I got I destroyed pretty fast, in a few months. That first 5 ah pack got discharged below 3.5v many times, and was used in a harsh manner on a racing bike. So it's definitely cruicial to carry enough to stop at a more reasonable dod rather than hit lvc every ride. Mostly it just really helps avoid a lot of time consuming balancing charges.

I just figure on two years of prime use from lipo now, whether it's lots of miles or not. I try to keep only what I need charged to 4.1v, and the rest at less than 4v, but charged enough to charge up to 4.1v and use in less than hours.

So I was a loser, in cycles or miles, but proved that when they say don't store fully charged, they are right. However, I also proved you get two years even doing it wrong.

 

[recumbent]

I'm not trying to nit pick on you, I just wanted to help you out with your units since you seem to be mixing them up.

0.002 V = 2 mV
0.020 V = 20mV

0.020mV = 0.00002 V... this is 20 uV (micro volts)

Thanks for posting your stats.

Thanks "Zombiess", I wasn't sure about the lingo, just the numbers on the Celllog.

 

[Kingfish]

The most miles I ever got on a single charge was about 167 miles; the distance between San Rafael and Fort Bragg in California on an August day in 2011, and I was carrying 100 lbs. of LiPo in a 15S26P configuration - pulling a trailer.

Not long ago I managed to squeak out about 90 Seattle hilly miles on the same ebike using a 15S10P setup; no trailer - just a skimpy backpack with water. That is probably the best performance yet.

But really - this is all relative. Weight, weather, faring, amount of human contribution, terrain, mechanical system, wiring - they all factor in on how far an ebike will travel.

Pushing forward, KF

 

[dogman dan]

Re reading your original question, the way to get the lowest dollars per mile is to ride slow. Riding my cargo bike, I can crawl at 15 mph and get close to 12-15 watthours per mile. But the way I ride most of the time at 30 mph takes 40 wh/mi or more if windy.

Thinking in terms of total watthour life expectancy rather that cycles gives you a much better way to calculate real cost per ride. Here's how I feel it works. Right now I am using only RC lico, and my 48v 15 ah pack cost about $450 including shipping. I expect no more than 3 years use from it, and in reality, the pack will lose a great deal of it's capacity by the end of two years. Dying more from age than many cycles. Each week, I typically ride about 30 miles, using about 40 wh per mile.

So, 40wh x 30 is 1200wh per week. Multiply times 104 weeks gets you 124,800 watthours I expect to get for my $450. $.0036 per wh. A typical mile then costs $.144, or 14 and a half cents per mile. Gas for my car costs 12 cents per mile currently. But the cost of the bike is so much less than a car, that it's still saving a fortune every mile I take the bike instead.

There's my battery cost per mile, the way I use it. The way I use it, it will be about 200 cycles. But others could realize double or half that cycle count, particularly doubling the cycle count by taking shorter rides.

FWIW, the cost per mile of my first pingbattery was about half that of the lico. But part of that is because the ping was bought at 2008 prices. Buy one now, and you will pay more for sure, about $200 more than the old 1c cells cost then.

I also use part of the same battery for other uses, so part of my battery may wear out sooner. That shouldn't really change the projected cost per mile. Also, I should be able to ride more that 30 miles a week average, decreasing my cost per mile. But, I don't expect a lifestyle change soon, and only so many trips to the grocery are needed. I figure if I ride 30 miles, it saves me about 15 bucks a week. Not big money, but enough to pay for some of the gas I do use.

 

[friendly1uk]

Spent about $70 on 3 4s 5ah bricks to make a 44.4v 5Ah pack. Spends it's life fully charged or in use. 4.2v down to 3v. 1250 miles so far showing no sign of degradation. That accounts to 5 cents per mile, carrying just 1.6kg of battery to take me about 10 miles at 20mph.

My initial expectation was 1600 miles before I drop below 80% capacity. I consider that dead, but beware, many folks talk about there packs being good, when in fact they are well below this design threshold.

 

[dogman dan]

That's true. I seriously discount folks that say their lico is still good at 3-4 years. I think they use a larger pack, and still get good use from batteries approaching 50% loss of capacity. No loss of capacity is tough to believe, unless they are talking about less than 1c discharge rates. I find my old lico gets really sensitive to a 2 or 3 c discharge rate.

This is what I got from my 3rd year of use with my first set of lico. I use it occasionally to extend range. But to add 10 ah of range to my existing usable 13 ah, I have to carry at least 20 ah more. I get between 2 and 3 ah from the old 5 ah packs, and that's at rates below 1c.

 

[friendly1uk]

Thanks Dogman. Your numeration is very useful to me. With my usage, my pack will last at least a year, or maybe 18 months. It also carries me far enough. If I were to upgrade, I would want to stick with the cheap 5ah bricks, making my pack last 2 too 3 years. By 3 years it's going to die of old age though. It is a close call if I could use a 10ah pack quick enough, and when we consider the doubling of my packs weight it makes the 10Ah pack a bad idea. A 20Ah pack would ruin my build entirely. What I'm going to do is keep this pack as a spare when it dips to 80% so I can do as you do, and just carry it on the bike occasionally as an auxiliary range extending pack. 12-18 months later, the bikes main one will be replaced again, and move in to this auxiliary role. This auxiliary battery will then be retired completely between 2 and 3 years old. Perhaps still with 80% capacity. In which case I will offer them for free.

 

[dannyboyohyeah]

That was quite an analysis, and very useful. It perhaps reveals that my intial question was not a good question. Life of batts has much more to do with how we treat them, than how we build them, which everyone already knew. But at least I sort've know what to expect now, as to the "possible" life left in my pack.
But you also demonstrated that in fact we are all abit crazy, out there in the wind and the weather and risking crashes for about the same money as gallons of gas. Still, I prefer it this way, and don't even have a car anymore. Slow is good. Scenic routes help.

 

[dogman dan]

The savings is in the not putting miles on, or owning a car at all. Gas costs are a tiny fraction of car use costs.

My current daily rider is very expensive as ebikes go. It's huge, it's fast, it's covered with saddlebags that catch the wind like a tying a trash can to the bike. Previous smaller and slower ebikes have been at least 6 cents per mile cheaper to operate. Cost of the battery per mile goes way down if you ride slow. Now I ride this thing at 30 mph most of the time.

But, Its still a ton cheaper per mile than a car. Assuming 10,000 miles, including several sets of tires and brake pads, the bike itself costs about 7 cents per mile. So all in, about 21 cents per mile. This is very comparable to a gas moped in total costs, but the moped could only carry a fraction of what that longtail can carry. In addition, the 50cc gas moped sucked in many ways. Noisy, spewing stinky 2 stroke smoke, and vibrating your hands and ass to death.

The longtail on the other hand is just as fast, but oh so much more pleasant to ride, adjustable to fit my body, and can carry a shitload of groceries, or even tour long distances.

Another vehicle worth comparing with is the small motorcycle or scooter. 150cc. About the same cost per mile, at 25 cents or so in my state, and my good driving record. But the china scooter I had was designed to fit a tiny person. I tried this and that, and it simply could not fit my body. It was unbearable to ride it further than 5-8 miles. I'm comfy on the cargo bike for at least 30 miles. It was faster by far, but unusable to commute to work for me. On the streets, the speed limit made it no faster than the bike, and on the freeway it was terrifyingly too slow. I found riding it on the streets tedious, since I could not use all my bicycle short cuts. In my town, a bike can go routes cars cannot.

I am still interested in a larger scooter, but don't have cash to buy one now. The Suzuki Burgman 350 fits my body just fine. I passed on a great deal on the 650, since I did not want that much speed and power.

Anyway, I've tried this and that, had motorcycles and scooters from 50cc to 750cc, and still find that ebike to be my favorite way to get around. The cost is one reason to bike, but on the list of 100 reasons, it's about number 70.

 

[dannyboyohyeah]

Dogman~
That's quite a mule you got there. It looks like you've got twice the stuff on there I could fit on my Bob trailer, too. I can't believe that standard rear wheel and tire can take it. If you ever have occasion to strip 'er down (unload all that stuff).... I'd like to see how you made that rear, add-on triangle. Happy Trails.
ps.... I really am not counting dollars or pennies as to motivation for ebikes. I just love two wheels and can't risk motorcycles anymore. But our lives are made of miles ridden and things done. Thanks for your contributions.