Sick of manipulated dealer specs!

[Spacey]

For 15mph your energy needs are reduced somewhat compared to 25mph....I have a dastardly plan come the new year to do a real report on range on ebikes.

I will buy one ebike and test it 100%, if it falls short as it will I will then take it back on that day as clean as I bought it and ask for a refund. All the data I have gathered will then be uploaded to a site I will build then on to my next bike until I have covered as many as I can.

I hate bullshit marketing.

 

[MadRhino]

...bullshit marketing.

Is that a pleonasm, or tautology ? :wink:

Litterally, selling bullshit require some sort of lie at the least, else one would have to target a very specific market.

 

[Ykick]

Dogmans rule of thumb for 48v is about .75 ah per mile.

Stating AH per mile without stating the voltage is every bit as stupid as stating range without stating speed.

And nearly as stupid as stating wh/mi, to a noob who barely understands AH. And BTW, nearly all battery sales pages don't say what the wh capcity is. What size is your HK pack? It's stated in milliamphours. So your noob is going to have to calculate to get wh, when he's clueless what a wh is.

At some point, you have to start talking in wh. Obviously this is the universal measure, and it SHOULD be the way a battery is specified in the for sale page. Wh/mi is the only way to accurately measure the efficeincy of a ride, and works to compare any bike to any other bike, regardless of voltages.

The stupid rule of thumb is just used to get people with no experience to have some kind of clue if the bike can do thier commute. Not how far is the max the bike could potentially go. But how far the bike could reliably go in average conditions, AND have some reserve capacity for the messed up day you get to ride home into a 40 mph wind.

That's why it's a rule of thumb. Ive never called it an accurate calculation of range. If anybody wanted that, I'd have to explain wh, wh/mi, and the whole thing. Or I can just type, "you have a 13 mile ride, so a 36v 10 ah battery will be undersize if you want to ride 25 mph. Why? then I quote the rule of thumb.

+1... And to further murky the water - which 48V are nit pickers talking about? SLA, Life, NiMh/NiCd, RC Lipo? Hell, I consider 12S Lipo 48V since it spends way more discharge curve above 48V. Most here consider 12S 44V nominal but anybody running 12S Lipo down to 44V will be cooking those cells. 15S Lipo is about done at 55V and quite a ways from 48V but still probably in the window to be called 48V system.

Nothing stupid about it IMO. 1Ah/mile operating between 40-60V is a very safe and surprisingly accurate estimate which is based on experience more than detailed math formulas. It's a quick and easy calculation with enough room for errors so that users won't be left stranded with no propulsion for a heavy bike.

 

[dogman dan]

I haven't done the testing to come up with a rule of thumb for 12s lipo. Both of my rules of thumb are based on lifepo4, based on my experience with 36 and 48v pingbatteries. So 48v, is actually about 48-56v, with the meat of the discharge at 54v. 12s is just about halfway between 48v and 36v in my opinion. 14s = 48v ping in voltage.

So I'll guestimate .85 ah per mile for 12s. After I ride 500-1000 miles on 12s I'll let you know. Right now it's a guess. My 6s packs have been running a lawnmower. I've barely had them on the bike at all. You don't get a rule of thumb by riding around the block a few times. It takes riding in all weather, uphill, downhill, into wind, etc.

 

[nonlineartom]

Again I think 1AH per mile @ 36V is an accurate rating, I used to get 12 miles out of my 36V 15Ah (actually 12ah) pack riding on road or riding off road trails with pedalling. I could get the numbers up a bit with more pedalling but generally, it was 12 mile range with 12Ah. That was a 30A controller. On a 15-20A controller with a 15mph top speed I managed to squeeze 25 miles out of the battery with constant pedalling. Hills seem to be the real big killer, today on a ride I used 1ah travelling several miles on the canal tow path and then used another 1ah going up a 100 meter steep hill in a very short space of time.

 

[dogman dan]

Your experience mirrors mine. It's not a rule of thumb based on a couple test rides, but based on many many rides in various conditions. Eventually you see, yup, the range on a 10 ah pack is somewhere between 8 and 12 miles, at 20-25 mph, with light pedaling. Depending on hills or wind.

Again, I don't care if they do claim 30 mile range for a 10 ah pack, just tell us you pedaled and went slow. It's fun to report your personal best wh/mi. But not right to say a bike gets that normaly. That is, if normal is 20 mph riding with light pedaling.

 

[Gordo]

Spacey,
Look at these guys, identical motor but one dealer say 30lb thrust and the other shows both 40 & 50 for the same motor.

 

[dogman dan]

At least you get to pay more for the 50 pound thrust one. :wink: Sadly, bald lying in ads is becoming more and more standard. You didn't really think you were going to find that advertized TV at best buy did you?

 

[Gordo]

At least you get to pay more for the 50 pound thrust one. :wink: Sadly, bald lying in ads is becoming more and more standard. You didn't really think you were going to find that advertized TV at best buy did you?

This bestbuy bullshit almost got me on a MB. But, I paid the manager a visit and asked him to look on the computer to prove they even had the bike either in stock or on order. When he looked, he found they did not, so he sold me a $599 bike for $249 IIRC.
As I'm now looking for a TV, I won't bother looking in the flyer's. A friend with TV stores told me to wait until the end of January.