18650 Li-ion at $145 per KiloWatt Hour!

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DrkAngel   100 GW

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 13 2011 5:30pm

My present, home made, 84cell - 18650 (2600mah) pack 25.9v - 31.2ah, will motivate me, at 16mph for 40 miles, motor only - no pedal assist.

If comparable in quality to my (salvaged from old, bad notebook batteries, many year old, 2600mah rated cells), then the UltraFire 3800mah cells (45.6ah) should extend that range to 58 miles!

Oh ... my bike is a comparatively inefficient, a brush, geared, non-hub motor.
So ... a brushless hub motor might give you 70 - 80 miles, or more?

And the battery would hold approx 1kwh. Which makes for some easy math when comparing to gasoline cost efficiency.
USA electricity is right near $.10/kwh, gas is about $4/gal. let's say 75miles/kwh x 40kwh/gal = 3000 eMPG. (40 x 75 =3000)

The equivalent of 3000 eBike miles for the fuel cost of 1 gallon of gasoline!
A car that gets 30mpg pays 100 times as much, per mile, (10,000% more.)
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by redorblack » Mar 13 2011 6:23pm

Just watch out for that brand... or any trustfire/ultrafire cells. Test them first and read the reviews... I went with Trustfire 2400mah cells(black) for my flashlights based on recommendations over at candlepowerforums. Unfortunately I did get one dead cell on arrival out of the 6 cells I've purchased so far, but at under $10 pair delivered it's still cheaper than anything else I've seen in that format that actually hits it's rating.

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 13 2011 6:33pm

grindz145 wrote:even the high quality lico cells have low discharge rates.its a function of the cell impedance.if you're interested I'm building a 2+ kwh pack then these might make sense, but that's still a ton of cell terminations to make, not to mention the safety risk. Just things to consider.
My concern exactly.
If you are drawing 30 amps, and these cells are happy at 0.5C, then you need a 60amp hour pack on your bike.

I don't think that is possible to even fit on a bicycle in the first place. And you won't even get the full capacity as 0.5C is overdoing it on those things, apparently.

Seriously, anything that has a worse C rating than a ping is worth $0 in my eyes. You will be beating on those cells, they will get hot, you won't get all the AH out of them, and they'll live a long life.

If you can only go 16mph on those cells, then your pack must be sagging many many volts from all the internal resistance. Try some lipo or headways on for size and i think you will scoff at the idea of using cells like this.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 13 2011 7:11pm

Top motor speed on EZips is 16mph. Re-gearing motor allows 20mph. Distance trial was made at max oem speed, for comparison purposes against "stock" bike with SLA battery.

The UltraFire, apparently, provide 80% of rated at 1-2C.
SLA provide 60% at, much less than, 1C.
1C draw expends battery in 36min.
So actual out put is .6C for 1 hour = 60% of rated. (SLAs are typically rated at 20hr, usually noted on upper right = .05C)
Ultrafire 3800mah .5C = 90% of rated.

84 UltraFire 3800mah cells (45.6ah), smaller than 2-10ah SLA, could motivate my EZip at 16MPH for almost 4hrs with a draw of about .25C, with an efficiency of, possibly, 95% of rated capacity.

Modified EZip, 450w motor, at 20mph has a draw of well below 20amps, equaling a draw of much less than .45C, possibly only .4C = well above the 90%!

And, my bike uses a brush, geared, non-hub motor. A more efficient motor might draw 20% less!

I've built many Li-ion packs over the years. Sample:
http://endless-sphere.com/forums/viewto ... 93#p375433
Last edited by DrkAngel on Mar 14 2011 12:35am, edited 2 times in total.
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 13 2011 10:58pm

DrkAngel wrote:84 UltraFire 3800mah cells (45.6ah), smaller than 2-10ah SLA, could motivate my EZip at 16MPH for almost 4hrs with a draw of about .27C, with an efficiency of possibly 95%.
There is no way your eZip is 95% efficient.. I don't even know of any brushless motors in the eBike world that are that efficient. Assume 70-80%
DrkAngel wrote:Modified EZip, 450w motor, at 20mph has a draw of less than 20amps, equaling a draw of less than .45C = above the 90%!
That would be a crusing speed, not on hills or during acceleration. Have you ever hooked a watt meter / cycle analyst / etc to your bike to find out your actual usage?
DrkAngel wrote:I've built many Li-ion packs over the years. Sample:
http://endless-sphere.com/forums/viewto ... 93#p375433
I've seen your packs and ya know, those cells weren't really designed to be ran at 1C ( 20 amps on 20 amp hours ) . And i think these ultrafires are worse if they won't even deliver their full rated capacity at half a C. If there is any C rating at which they deliver their full capacity, it is probably .25C or lower.

People complain about PING batterys having massive voltage sag when they are ran at the rated 1C. I cannot imagine how bad these trustfires/ultrafires are then O_O.

These may be cheap but you need a lot of them to provide adequate power.. and god only knows what their charge rate is..
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by liveforphysics » Mar 13 2011 11:31pm

DrkAngel wrote:3.7v 3800mah Li-cells available for less than $2 each!

Batteries to complete a 37v 26.6ah pack for $140 @ about 8lb!
Charger & circuitry extra.
"Pack" build method?
Soldering? Wired "rack"? ???


That equals $145/kwh - @ less than 10lbs. A 20kwh battery pack, for less than, the weight of a 200lb passenger!!!

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... K:MEWAX:IT

"** Large Quantity ** of UltraFire 18650 3800mAh Rechargeable Battery are available to purchase.
Please check out other Quantity items on sale.
If you do not see the "Quantity" you need. Please contact us and we can open an auction for you to buy.
More Quantity, More Discount!"

Price per 100 is noticeably more, due to:
Weight limitations of air mail?
Li-ion shipping safety regulations?

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... K:MEWAX:IT

I have tested, lower capacity, UltraFire 18650's, previously, and found them to be of reasonable quality and to be "rated" responsibly.

I would recommend purchasing a limited quantity, and testing before committing to, large scale, purchases.

I will, of course, post my test results as soon as possible ...



Ultrafire is the rebrand of failed cells from various batches. Started from the DealExtreme guy.
I've never had one make even 2/3rds of its rated capacity, and then they die in about 50 cycles. Perfect for a flashlight. Retarded for an EV.
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 12:10am

neptronix wrote:
DrkAngel wrote:84 UltraFire 3800mah cells (45.6ah), smaller than 2-10ah SLA, could motivate my EZip at 16MPH for almost 4hrs with a draw of about .27C, with an efficiency of possibly 95%.
There is no way your eZip is 95% efficient.. I don't even know of any brushless motors in the eBike world that are that efficient. Assume 70-80%
.27C draw resulting in 95% usable of rated Li-ion capacity! Sorry for the confusion.
And yes, if you looked, you would see that I have, multiple times, stated that my geared, brush, motor is 20%, or more, less efficient than a brushless motor!
neptronix wrote:
DrkAngel wrote:Modified EZip, 450w motor, at 20mph has a draw of less than 20amps, equaling a draw of less than .45C = above the 90%!
That would be a crusing speed, not on hills or during acceleration. Have you ever hooked a watt meter / cycle analyst / etc to your bike to find out your actual usage?
Yes, cruising speed! On the level! Identical course! Best way to provide accurate comparison between different configurations!
My digital amp meter connected, at battery, tells the best story, (a second by second actual usage). But I tend to rely on battery capacity divided by miles motored, factoring in the maintained speed.
neptronix wrote:
DrkAngel wrote:I've built many Li-ion packs over the years. Sample:
http://endless-sphere.com/forums/viewto ... 93#p375433
neptronix wrote:I've seen your packs and ya know, those cells weren't really designed to be ran at 1C ( 20 amps on 20 amp hours )...
These may be cheap but you need a lot of them to provide adequate power.. and god only knows what their charge rate is..
My 25.9v 31.2ah pack never exceeds 30amps, even full throttle from a dead stop, and ... it drops noticeably below 20 amps, being used, at 22mph+!

Just looked up multiple manufacturers, product specs, for their 18650 Li-ion cells, they are rated at 1.5C continuous output ... and 1.5C charging! No! ... I won't make you call me god!

That means that my proposed 45.6ah pack, is capable of about a 70amp sustained output.
That is about 3 times my "surge" usage, and more than 4 times my "typical", cruising, usage.
And, can be fully recharged in 40 minutes!(Just need a powerful charger)

My eBikes, only draw, from below 15, to less than 30 amps.
And I charge overnight, with a much cheaper charger.

Li-ions might run 90% rated capacity at .5C.
SLAs run at 60% rated capacity at.6C. Rated capacity is at 20 hours! SLA = .05C
I've never heard of any battery exceeding a 90% rated capacity at .5C. 80% at 1-2C either!

What does any better? ... ???
Last edited by DrkAngel on Apr 25 2011 9:58am, edited 3 times in total.
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 12:41am

DrkAngel wrote:.27C draw resulting in 95% usable of rated Li-ion capacity!
And yes, if you looked, you would see that I have, multiple times, stated that my brush motor is 20%, or more, less efficient than a brushless motor!
Usually when people talk about efficiency, they are talking about the efficiency of the controller and motor, not how efficient the battery is. I don't even know if calling a battery 'efficient' is correct in the first place. See how i got confused there?

Also, 20amp discharge on a 20amp pack is not .27c, it is 1C.
DrkAngel wrote:Yes, cruising speed! On the level! Only way to provide accurate comparison between different configurations!
Digital amp meter connected at battery tells the best story. But I tend to rely on battery capacity divided by miles motored, factoring in the maintained speed.
No, not really, you need to look at peak amps as well. In fact, all batteries should be chosen with peak amps in mind, not cruising amps.

This is so that you don't exceed the cell's discharge rating when taking hills or accelerating from a stop or lower speed.

If you watch your digital amp meter, you'd know that there is a lot of variance in amp draw.
DrkAngel wrote:My 25.9v 31.2ah pack never exceeds 30amps, even full throttle from a dead stop, and ... it drops noticeably below 20 amps at 22mph+!
That's good, but you still need to design your battery pack around the 30 amp number. Often time the cycles rating is *much* lower than the discharge rating.
DrkAngel wrote:Just looked up multiple manufacturers, product specs, for their 18650 Li-ion cells, they are rated at 1.5C continuous output ... and 1.5C charging!
For the Ultrafires?
That seems to conflict with every review of ultrafires i have ever seen on dealextreme and elsewhere.

They do not live up to their specifications in any way.

Even dealextreme puts big quotes around their capacity ratings.
Ahh, their site seems to be down so i can't even quote them..

But check this site:

http://lygte-info.dk/info/Batteries18650-2011%20UK.html

Image

The 3600's deliver less than 2500mAh at 0.2amp draw. More so around 2300mAh at 0.5amp draw. That means you are getting 33% less AH. So if you build a 40ah pack, you have in reality more like 26AH.

That's best case scenario, assuming these cells aren't actually worse than advertised.
DrkAngel wrote:Li-ions might run 90% rated capacity at .5C.
SLAs run at 60% rated capacity at.6C. Rated capacity is at 20 hours! SLA = .05C
I've never heard of any battery exceeding a 90% rated capacity at .5C. 80% at 1-2C either!
Depends on the lithium cell's chemistry. The laptop cells you seem to be fond of have very low C ratings, often in the 0.5-1c range.

The reason you don't get all their capacity is that you are running them over their comfortable C rating and they are most likely turning some of that energy into heat because of it.

Lipo gives me 100% of it's rated capacity at the 7C i have been discharging it at lately.
Better lifepo4 cells like headways etc. give you 100% capacity at the 1C-2C also from what i have seen.

If you're okay with carrying around a 40AH pack and still getting low cycle life and bad voltage drop when you hit the throttle, go for it. I'm not stopping you.

I'm just saying that these batteries are not all that.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
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Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by liveforphysics » Mar 14 2011 2:00am

You guys are forgetting the most important part. Ultrafire doesn't even MAKE cells. They are just a re-shrink-wrapper of cells that fail QC from manufactures.

Ultrafire = Most sh*t lithium battery on earth. Running them as a single cell flashlight is OK because it doesn't need to match capacity or resistance or anything, it just needs to be able to light an LED for a little while.



Lastly, the absolute best 18650 cell capacity that I've ever tested, a "3.1Ah" panasonic cell only did 2.8Ah at 0.2amp discharge. Ultrafire doesn't make cells, just re-label the failures of other mfg's, so the odds they are going to get to anything near 2.8Ah at a uselessly low discharge, or even 2.3Ah at an EV useful discharge level is pretty much slim to zero.
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 2:06am

neptronix - If as you say, you are discharging your battery at 7C, then it would be empty in less than 9 minutes! At 30 mph you would only have a range of 4.5 miles. Seems almost worthless to only be capable of going 2 miles, and back. ??? My wimpy Li-ions give me 30-40 mile range. Even the oem crappy EZIP SLA batteries gave me twice the range you're getting!

I'm not saying these batteries, (UltraFire), are "anything"! As I have said repeatedly, they look like a good deal, but I am buying a few, to test, before I consider buying any quantity!

As for my notebook cells, I picked them up 3 years ago, discarded and called "bad".
Sorted and built packs that have 5 times the range-capacity of the 24v oem SLA batteries, but smaller and at about 1/2 the weight.
Each have been recharged hundreds of times, and are still running strong.

And yes, I have built many different types of battery packs.
My first EZip upgrade was a bank of 20 - 7ah D cell NiMh, which I quickly upgraded to dual banks.
Then 36v SLA in a toolbox, on my rack.
Then I found Li-ion, tried a 10ah first, decided on 20ah as minimum, built 3 and have used 2 for the past 3 years.
Got some newer EZips and built 25.9v 31.2ah packs. Never even came close to 1C usage!

I have 4 projects waiting:
20 - 1.2v 14ah NiMh "F" cells. (Stockpiled)
180 - 3.7v, 2160mah Li-Po cells. (Stockpiled)
120 - 3.2v, 5000mah Li-Fe cells. (Stockpiled)
84 - Li-ion cells (12 banks of 7 cells 25.9v) & PCB (Protect & Charge Board) in a EZip battery case.
(Alternately to internal PCB, is an external connector to an iMax B8)

PS The Tesla Roadster uses 18650 Li-ions!
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by Hillhater » Mar 14 2011 4:09am

PS The Tesla Roadster uses 18650 Li-ions!
...Tesla Motors battery pack contains 6,831 lithium ion cells arranged into 11 "sheets" connected in series; each sheet contains 9 "bricks" connected in series; each "brick" contains 69 cells connected in parallel (11S 9S 69P). The cells are of the 18650 form-factor commonly found in laptop batteries...
... A fully charged pack stores approximately 53 kWh at a nominal 375 volts and weighs 992 lb (450 kg).
So, 53 kWhr @ 375 v = 141.3 Ahr
with 69 cells in parallel, that is 2.04 Ahr per cell ... of the best cells available !
...The roadster is powered by a 3-phase, 4-pole electric motor, producing a maximum net power of 185 kW...
185kW @ 375v =493A peak
equivalent to 493/141.3 = 3.5C peak
..Those wont be Ultrafire cells ! :roll:
....The Roadster is .. the first production BEV (all-electric) to travel .. The world distance record of 501 km (311 mi) for a production electric car on a single charge ..on October 27, 2009, during the Global Green Challenge in outback Australia, in which it averaged a speed of 25 mph (40 km/h)
..which means 501 kms @ 40km/hr took 12.5 hrs (impressive) ..and averaged 4.24 kW (11.3 A) .. draw..
.. or equivalent to 0.08 C !

Typically..
...According to the U.S. EPA, the Roadster can travel 244 miles (393 km) on a single charge....
and assuming an average of 100km/hr that would imply 13.25 kW average = 35 A average draw.
.. or equivalent to 0.25 C !
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 5:17am

DrkAngel wrote:neptronix - If as you say, you are discharging your battery at 7C, then it would be empty in less than 9 minutes! At 30 mph you would only have a range of 4.5 miles. Seems almost worthless to only be capable of going 2 miles, and back. ??? My wimpy Li-ions give me 30-40 mile range. Even the oem crappy EZIP SLA batteries gave me twice the range you're getting!
That's not the case at all. I pedal and i get a 10 mile range on 5ah of 36v power.
My ( moderate ) pedaling cuts the amps from ~38amps peak while accelerating to ~20amps cruising.

Oh 20AH of lipo i would be getting that 40 mile range.
Dunno about your terrain but mine is mildly hilly with a full stop every mile on average.
DrkAngel wrote:PS The Tesla Roadster uses 18650 Li-ions!
Yes, and much like a prospective pack with these ultrafires, you would need gobs more amp-hours than necessary, just to output decent power.

They didn't put a ~200 mile battery in it for the hell of it. Back in 2006, they didn't really have anything better than laptop cells. They couldn't make a more affordable Tesla Roadster with a 100 mile range.

It is newer chemistries and larger format cells that have made modern EV's useable. Less weight in the cell casing via prismatic cells. Higher output / lower internal resistance.

Of your packs that you have to put together, i say assemble the lipo first. You will see a noticeable difference. Even on my 5ah pack i only dive about 3 volts when i have the throttle at 100%. When the 20ah pack is fitted to the bike, i should be seeing less than 1v of dive. Tis a thing of beauty ;).
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 9:17am

neptronix wrote:
DrkAngel wrote:neptronix - If, as you say, you are discharging your battery at 7C, then it would be empty in less than 9 minutes! At 30 mph you would only have a range of 4.5 miles. Seems almost worthless to only be capable of going 2 miles, and back. ??? My wimpy Li-ions give me 30-40 mile range. Even the oem crappy EZIP SLA batteries gave me twice the range you're getting!
That's not the case at all. I pedal and i get a 10 mile range on 5ah of 36v power.
My ( moderate ) pedaling cuts the amps from ~38amps peak while accelerating to ~20amps cruising.

Oh 20AH of lipo i would be getting that 40 mile range. ...
Well ... my "old" Li-ion - 31.2 ah@25.9v is only slightly larger capacity than your assumed 20ah@36v Lipo, but I can get a "real world" 40 mile range!
With a brush-geared motor!
Without pedaling!!!!

(30ah@24v=20ah@36v)

By your stats, it looks like my old, beat-up, wimpy, li-ion batteries are outperforming your Lipos!
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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by zombiess » Mar 14 2011 1:00pm

DrkAngel wrote:
neptronix wrote:
DrkAngel wrote:neptronix - If, as you say, you are discharging your battery at 7C, then it would be empty in less than 9 minutes! At 30 mph you would only have a range of 4.5 miles. Seems almost worthless to only be capable of going 2 miles, and back. ??? My wimpy Li-ions give me 30-40 mile range. Even the oem crappy EZIP SLA batteries gave me twice the range you're getting!
That's not the case at all. I pedal and i get a 10 mile range on 5ah of 36v power.
My ( moderate ) pedaling cuts the amps from ~38amps peak while accelerating to ~20amps cruising.

Oh 20AH of lipo i would be getting that 40 mile range. ...
Well ... my "old" Li-ion - 31.2 ah@25.9v is only slightly larger capacity than your assumed 20ah@36v Lipo, but I can get a "real world" 40 mile range!
With a brush-geared motor!
Without pedaling!!!!

(30ah@24v=20ah@36v)

By your stats, it looks like my old, beat-up, wimpy, li-ion batteries are outperforming your Lipos!
DrkAngel, I don't think neptronix is bashing on your setup or 18650 setups in general. I believe he is just stating that these cells are far from ideal for an EV because of their over stated capacity and low C discharge ability. I believe most people on here realize that good quality 18650 cells are more than capable of being used in an EV since it's been done many times.

40 miles without pedaling is very impressive, but speed and terrain also plays a very large factor in how far one can go on a pack as I'm sure you already know.

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 2:14pm

DrkAngel wrote:Well ... my "old" Li-ion - 31.2 ah@25.9v is only slightly larger capacity than your assumed 20ah@36v Lipo, but I can get a "real world" 40 mile range!
With a brush-geared motor!
Without pedaling!!!!

(30ah@24v=20ah@36v)

By your stats, it looks like my old, beat-up, wimpy, li-ion batteries are outperforming your Lipos!
Lol, it's not that easy to compare dude. Remember that i am going 20-28mph and incurring all the aerodynamic drag from going that fast. If i didn't pedal, my cruising amps would be lower too. I also have a good amount of stop and go as those are city miles, as well as some rolling hills.

Come to Oregon sometime and we can come to a conclusion on this dick measuring contest :lol:
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 3:45pm

neptronix wrote: If i didn't pedal, my cruising amps would be lower too.

Come to Oregon sometime and we can come to a conclusion on this dick measuring contest :lol:
How in the world can you imagine that you would use less amps, if you stop pedaling?

Then you would be back to your 4.5 mile range!
Using twice the amps!
Not less!

Now you are just being re dick u less!

Sorry about the spelling, just thought I'd lay er down and roll er out a ways .............
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 4:17pm

DrkAngel wrote:
neptronix wrote: If i didn't pedal, my cruising amps would be lower too.
Come to Oregon sometime and we can come to a conclusion on this dick measuring contest :lol:
How in the world can you imagine that you would use less amps, if you stop pedaling?

Then you would be back to your 4.5 mile range!
Using twice the amps!
Not less!

Now you are just being re dick u less!

Sorry about the spelling, just thought I'd lay er down and roll er out a ways .............
Ever watched an amp meter before? once you hit maximum speed, amps are lower.
When you stop pedaling, you just go slower.

When i said 7C; that's my maximum amp draw and not my constant.
I already mentioned to you that i draw about 20 amps constant just like you do.

Why are we measuring penii again?
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 4:56pm

neptronix wrote:
DrkAngel wrote:
neptronix wrote: If i didn't pedal, my cruising amps would be lower too.
Come to Oregon sometime and we can come to a conclusion on this dick measuring contest :lol:
How in the world can you imagine that you would use less amps, if you stop pedaling?

Then you would be back to your 4.5 mile range!
Using twice the amps!
Not less!

Now you are just being re dick u less!

Sorry about the spelling, just thought I'd lay er down and roll er out a ways .............
Ever watched an amp meter before? once you hit maximum speed, amps are lower.
When you stop pedaling, you just go slower.
and ... your amp usage steadily rises, till the battery is capable of maintaining full speed, by itself.
With you assisting, battery might supply 20amps, at 25mph.
Stop pedaling and battery might drain 30amps to maintain 20mph!

Better try your amp meter again! I think you'll find me to be right.

Oh! Make sure you put the amp meter on the battery side, not the motor side!
Motor side is subject to amperage, but also, voltage fluctuations, which might account for your ridiculous conclusions.
neptronix wrote:Why are we measuring penii again?
I don't know?
You're the one who stuck it out there ... to get stepped on!
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 5:03pm

Better try your amp meter again! I think you'll find me to be right.

Oh! Make sure you put the amp meter on the battery side, not the motor side!
Motor side is subject to amperage, but also, voltage fluctuations, which might account for your ridiculous conclusions.
neptronix wrote:Why are we measuring penii again?
I don't know?
You're the one who stuck it out there ... to get stepped on!
Of course the amp meter goes on the battery side, i have a 3 phase brushless motor :p
Battery is also subject to voltage fluctuations due to internal resistance.

My conclusions are not ridiculous, this is the range i get in real life.

And my batteries output 100% of their rated capacity, because i am drawing far below their rated capacity at peak ( 7C on a 5ah pack, or 1.75C on the 20ah pack )

I think you misunderstood me at some point in this posting. Or perhaps i was not clear.

All my figures on the 20AH pack i have are basically the result i get from the 5AH pack i normally ride on, multiplied by 4.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 5:18pm

neptronix wrote:
Better try your amp meter again! I think you'll find me to be right.

Oh! Make sure you put the amp meter on the battery side, not the motor side!
Motor side is subject to amperage, but also, voltage fluctuations, which might account for your ridiculous conclusions.
neptronix wrote:Why are we measuring penii again?
I don't know?
You're the one who stuck it out there ... to get stepped on!
Of course the amp meter goes on the battery side, i have a 3 phase brushless motor :p
Battery is also subject to voltage fluctuations due to internal resistance.

My conclusions are not ridiculous, this is the range i get in real life.

If i didn't pedal, my cruising amps would be lower too.
Ever watched an amp meter before? once you hit maximum speed, amps are lower.
When you stop pedaling, you just go slower.
and ... your amp usage steadily rises, till the battery is capable of maintaining full speed, by itself.
With you assisting, battery might supply 20amps, at 25mph.
Stop pedaling and battery might drain 30amps to maintain 20mph!
I say, you are being ridiculous, when you claim that you use less amps, when you stop pedal assisting!
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 5:35pm

DrkAngel wrote:]and ... your amp usage steadily rises, till the battery is capable of maintaining full speed, by itself.
With you assisting, battery might supply 20amps, at 25mph.
Stop pedaling and battery might drain 30amps to maintain 20mph!
I say, you are being ridiculous, when you claim that you use less amps, when you stop pedal assisting!
With me assisting, i go 27-28mph and draw ~20amps crusing.
Without me assisting, i go 23-25mph and draw ~20 amps cruising.

Accelerating or hill climbing = peak amps, or very close.

And if you watch your amp meter, you know there is a difference between accelerating/hill climbing amps, that's why your eZip uses your claimed 20 amps to maintain speed and not the 30 or 35 amps the controller is rated at.

I think you missed something in my argument ?
Why are we arguing about the efficiency of my motor vs your motor here?

I think the main point is that batteries, if driven over their C ratings, deliver lower capacity and voltage sag gets progressively worse the higher you go over the C rating.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 6:19pm

neptronix wrote:
DrkAngel wrote:]and ... your amp usage steadily rises, till the battery is capable of maintaining full speed, by itself.
With you assisting, battery might supply 20amps, at 25mph.
Stop pedaling and battery might drain 30amps to maintain 20mph!
I say, you are being ridiculous, when you claim that you use less amps, when you stop pedal assisting!
With me assisting, i go 27-28mph and draw ~20amps crusing.
Without me assisting, i go 23-25mph and draw ~20 amps cruising.
Pedal assist - 5ah battery@20amps 28mph = 7 mile total range
Motor only - 5ah battery@20amps 25mph = 6.25 miles total range

Something must be wrong, since you claim a 10 mile range!
The good news is that all your pedaling effort only contributes 10%.
So ... you might as well not pedal!

When I pedal, my range increases 50-100%.
Either put a little more effort into it, or get a better amp meter!
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - February 2019

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 6:51pm

DrkAngel wrote:With me assisting, i go 27-28mph and draw ~20amps crusing.
Without me assisting, i go 23-25mph and draw ~20 amps cruising.
Pedal assist - 5ah battery@20amps 28mph = 7 mile total range
Motor only - 5ah battery@20amps 25mph = 6.25 miles total range

Something must be wrong, since you claim a 10 mile range!
The good news is that all your pedaling effort only contributes 10%.
So ... you might as well not pedal!

When I pedal, my range increases 50-100%.
Either put a little more effort into it, or get a better amp meter![/quote]

Yep, calculations are off either way. You can calculate things like this as much as you want drkangel, but your calculations will never take in account hills, start and stop, aerodynamics, the weight of the rider, rolling resistance, battery current wasted as heat, etc. It is a complete waste of your time.

Real life testing is the only way.

I do get 10 miles on 5 amp hours pedaling. In fact, my turnigy watt meter does report higher amps than actual; but also the infineon controller is known to exceed it's battery current rating, so i am not sure how far off it is.

My batteries were at 3.75v per cell so i probably had a mile or two left in them actually. That's almost an AH on lipo. My range estimation was probably on the conservative side. I probably had a mile or two left in the batteries. As for pedaling, it is at a moderate pace; just barely breaking a sweat.

Anyway can you remind me why we are still on the subject over who's system is more efficient than the other? This original conversation is about batteries.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by DrkAngel » Mar 14 2011 7:37pm

DrkAngel wrote:
neptronix wrote:
DrkAngel wrote:]and ... your amp usage steadily rises, till the battery is capable of maintaining full speed, by itself.
With you assisting, battery might supply 20amps, at 25mph.
Stop pedaling and battery might drain 30amps to maintain 20mph!
I say, you are being ridiculous, when you claim that you use less amps, when you stop pedal assisting!
With me assisting, i go 27-28mph and draw ~20amps crusing.
Without me assisting, i go 23-25mph and draw ~20 amps cruising.
Pedal assist - 5ah battery@20amps 28mph = 7 mile total range
Motor only - 5ah battery@20amps 25mph = 6.25 miles total range

Something must be wrong, since you claim a 10 mile range!
The good news is that all your pedaling effort only contributes 10%.
So ... you might as well not pedal!

When I pedal, my range increases 50-100%.
Either put a little more effort into it, or get a better amp meter!
neptronix wrote:Yep, calculations are off either way. You can calculate things like this as much as you want drkangel, ...
I do get 10 miles on 5 amp hours pedaling. In fact, my turnigy watt meter does report higher amps than actual; but also the infineon controller is known to exceed it's battery current rating, so i am not sure how far off it is.

My batteries were at 3.75v per cell so i probably had a mile or two left in them actually. That's almost an AH on lipo. My range estimation was probably on the conservative side. I probably had a mile or two left in the batteries. As for pedaling, it is at a moderate pace; just barely breaking a sweat.

Anyway can you remind me why we are still on the subject over who's system is more efficient than the other? This original conversation is about batteries.
Sorry ... I have a scientific mind, I eat up facts & figures.
When someone purports self-serving speculations, as fact, I have to jump on it, and shove it up in their face!
If you have to make up numbers, try to be a bit more realistic.
It's just too easy to spot false data, challenge me a little. ... Please!

Realistic estimate, for you:
Factors:
5000m ah battery
10 mile range
30mph (rounded up from 28mph, to simplify math.)
1ah unused (reputed residual charge)
10 miles at 30mph = 1/3hrs = 20 minutes
4000mah x3 = 12amp average usage
(28mph = 7% higher)
12.84 "cruising" amps

Better get a better amp meter.
You claim a 10 mile 28mph cruising range at 20amp "draw".
If, as you claim, battery usage was only 4 amps, then your actual "draw", was less than 13amps.

Bonus!
36v controller (90% efficient - approx)
500w hub motor (85% efficient - approx)
(4000mah X .9) x .85 = 3060mah x 3 = 9.16amp average actual on the road, power
(28mph = 7% higher)
9.8amp average actual on the road, power
Last edited by DrkAngel on Mar 15 2011 8:30am, edited 3 times in total.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - February 2019

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Re: 18650 Li-ion at $145 per KiloWatt Hour!

Post by neptronix » Mar 14 2011 10:33pm

Enjoy the ultrafires.
Efficiency is everything :bolt:

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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