18650 Li-ion at $145 per KiloWatt Hour!

neptronix said:
Enjoy the ultrafires.
Click to expand...

It's just too easy to spot false data, challenge me a little. ... Please!

Realistic estimate, for you:
Factors:
5000mah battery
10 mile range
30mph (rounded up from 28mph, to simplify math.)
10 miles at 30mph = 1/3hrs = 20minutes
1ah unused (reputed residual charge)

4000mah x3 = 12amp average usage
(28mph = 7% higher)
12.84 "cruising" amps

Actual cruising amp usage would be less than 13amps, not the ~20amp you purport.
Since you claim multiple stop-starts and hills, actual, level "cruise draw" might be less than 10amps.
Which, obviously, calls "suspect", your, identical, non-pedal claim of ~20amp usage!
Your claimed, "cruising draw", is more than 54% "off" from the maximum possible!

Obviously your data is wrong!
If due to faulty test equipment, this must be pointed out.
If due to incompetence, I can only recommend: "Don't mess with equipment you're incapable of understanding".
If an outright lie, to promote your own viewpoint, then it must be refuted ... vehemently!!!
 
neptronix said:
Lipo gives me 100% of it's rated capacity at the 7C i have been discharging it at lately.
Click to expand...
Wow! Everyone else only gets 90% rated capacity, at less than 7C!
lipo_discharge_curve_sm.png
Personally, I would rate fully expended, where the discharge curve, hits a 45degree angle, at the 85% of rated point. Beyond that looks about as effective as beating a dead horse. 30 seconds travel drops you from reasonable, to danger, voltage level! (Permanent Damage!)

I would like to know where "neptronix" got his unique, freakishly miraculous, battery?
 
Judging by the graph, neptronix's 5ah Li-po, expended at a lesser 6C, would be totally empty at 4.5ah.
Everything I've read, cautions that draining a Li-po below 20% greatly reduces the life and capacity of the battery.
Meaning that, if more than 3.6ah is used, serious damage is being done.

Deeply discharging batteries, high discharge rates, high recharge rates too, greatly shortens the life of Lipos. Examples cited 50 cycles for such "abused " batteries compared to 500 - 1000 cycles for more gently used cells.
Doubling the size of the battery would give you twice the range, and possibly, 10 times the lifespan!
 
ohay guys, random "first"ish post, but my review of these batteries, which I'm planning to put in a gigantic pack for a EV go kart.

Same batteries as listed, LC 18650 Ultrafire 3800mAh's. Took quite a while to charge.

1f3b49a4.jpg


I hooked up 3 in series and actually managed to turn over a 50lbs Raymond (newly rebuilt) forklift motor (which is going on the kart). Took the cells 5 seconds for it to fully rev up, and got HOT (rather weirdly, they all heated up a tad differently. One of them was MUCH hotter than the other two, despite measuring a higher voltage after that test - different internal resistances?). Positive I was drawing around 10-20A.

These these can take 1C no problem, personally hooked up a airsoft motor to it. Drew 4A and tapered down to 2.2A. (BTW, I'm assuming these are 2000mAh). Did it for 20 seconds, batteries didn't even get warm.

Anyone want a video? :p
 
If you have a balancing charger, it would be nice to see the voltage dip, and graph how much capacity is given at 1C, 2C, and 0.5C.

If they heat unevenly when pushed, that is a bad sign. That means cell quality could be real hit and miss.
We need a bigger sample though because 3 isn't enough, but so far it's looking like these are B grade cells of various quality.

Nonetheless welcoem to the forums and thank you for your report.
 
I have 27 more I can swap around in random pairs and try if you'd like me to :p

I don't have a balance charger unfortunately (I charge the cells up individually, and then put them in series). I have a balance charger for LiPo's, however, can probably adapt them somehow.

Yeah, that's what I was thinking. I'm planning on using the UF's either way for the battery pack, will hopefully make a video later. Will try and measure the voltage sag when the load is applied though.
 
If your balancing charger is compatible with logview ( hyperion, icharger, etc ) then i'd love to see some graphs.

Most lipo chargers can charge lifepo4 / other chemistries that have voltage ranges of 2.0v - 3.65v.
 
Got my test batch of 3800mah UltraFires.
Charged a couple, up to the nominal 4.2v.

Put 1 in a "300"lumen, (Yeah ... everything gets exaggerated), CREE flashlight, checked initial draw, .7amp, let it run ...
5 hours later, it had noticeably dimmed, 3.2v - .27amp.

Only test I had time for.
Doesn't say much, except it is no dud.
Lasted longer than various other makes of cells.
 
liveforphysics said:
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.
.
Click to expand...

And the award goes to !!

Just how bad is it ? .. well.. alot worse than i expected.. hehe.. exactly how much tbd soon.

Testing the 3.2ah red one's now.. so far i canot get them to take or deliver even 100 mah at 1 amp !!!
 
DrkAngel said:
neptronix said:
Lipo gives me 100% of it's rated capacity at the 7C i have been discharging it at lately.
Click to expand...
Wow! Everyone else only gets 90% rated capacity, at less than 7C!

Personally, I would rate fully expended, where the discharge curve, hits a 45degree angle, at the 85% of rated point. Beyond that looks about as effective as beating a dead horse. 30 seconds travel drops you from reasonable, to danger, voltage level!

I would like to know where "neptronix" got his unique, freakishly miraculous, battery?
Click to expand...


Hey retard, all LiPo is not the same. Showing some graph of some lame-ass crap is like showing a picture of a bad painting or something, and saying all paintings are bad.

I pull 5.4Ah from some "5Ah" cells. I pull over 5Ah from some 5Ah cells charging to 4.12v and discharging to 3.5v.


What we do KNOW.

There are NO 3800mAh 18650's on the public market.
The best in the world right now are a claimed 3.4Ah, and only deliver that at 0.25C discharge.
Ultrafire does not, and can not make batteries, it's a guy named Kai and his buddy who shrink-wrap the lots of factory reject cells with various shrink wrap labels that claim various things. They get the reject cells at the cost of the recyclable materials worth.


Making an EV or even a more than 1-cell use for unmatched garbage reject cells is about as smart as building your EV out of paper-mache, with the exception that you could conceivably have good results from a paper mache chassis if done correctly.


I should take my box of 500 garbage 18650's here under my desk, and order up a roll of shrink for them that says "1,000,000mAh" and put up a listing somewhere so you can buy them and be impressed with the performance.
 
liveforphysics said:
... I pull 5.4Ah from some "5Ah" cells. I pull over 5Ah from some 5Ah cells charging to 4.12v and discharging to 3.5v. ...
Click to expand...

Wow! What brand do you claim to deliver better than "rated"?

Or ... how are you determining the capacity?

Measured discharge?
Measured charge?
C rate???
 
Must be inside...nothing for it, gunna haveta autopsy it. :p
 
liveforphysics said:
I should take my box of 500 garbage 18650's here under my desk, and order up a roll of shrink for them that says "1,000,000mAh" and put up a listing somewhere so you can buy them and be impressed with the performance.
Click to expand...

oh man you got me rollin' on the floor...

BTW i have somehow drained 5.1AH from my lipos before, but that was on my wimply lil' 14a setup. No cells were below 3.0v.
Measurement was per the iCharger 1010b+. Can't think of a more accurate source than the charger itself..

The cells themselves have labels that indicate they are 5100-5200mAH in capacity to begin with, so it makes sense.
 
Lol... Omg...
So f*ucking clueless....

Modern lipo has around a 3.8-3.9v nominal, and has under 5% capacity left by the time it reaches 3.45v.

Likewise, its not a linear distribution between capacity and SOC voltage...


Ypedal- that ultrafire cell is somethig from an OEM pack it was spot welded into that failed QC. Likely a laptop pack. This is how ultrafire works.



DrkAngel said:
liveforphysics said:
... I pull 5.4Ah from some "5Ah" cells. I pull over 5Ah from some 5Ah cells charging to 4.12v and discharging to 3.5v. ...
Click to expand...

Wow! What brand do you claim to deliver better than "rated"?

Typical voltage for liPo is 4.2v fully charged and 2.8v fully discharged.
The rated capacity is determined by a 1.4v variance.

You are claiming a greater than rated capacity with a .62v variance?
Full capacity might be 11.3ah! ... ?

It would seem that you are claiming that some company is selling 11ah+, actual capacity lipo cells, and underrating them as 5ah.

What company is so incompetent, ... or just plain foolish?
Selling LiPo and rating them at only 45% of actual capacity?

Or ... how are you determining the capacity?
Something sounds way ... way ... way! ,,,,, OFF!
Click to expand...
 
DrkAngel said:
liveforphysics said:
What we do KNOW.

There are NO 3800mAh 18650's on the public market.
The best in the world right now are a claimed 3.4Ah, ...
Click to expand...

Panasonic announced their production of 4000mah 18650's, last year.

http://www.ecofriendlymag.com/susta...-application-of-silicon-based-alloy-in-anode/
Click to expand...


They are vaporware right now. They have an agreement with Tesla to try to deliver 3.6Ah first, and even at unobtainium pricing, there are ZERO in production and way behind schedule.

Silicon anodes will be kick-ass if they can get them past the 50-100cycle mark that a few Mfg's have been stuck on for the last 3-4 years...
 
In order to pass Li-ion safety regulations, some manufacturers might "throttle-down" or regulate the input-output rate capability, to the point that any possible excessive input or output could be safely dissipated as heat.
 
I like how the safety circuit is a single PTC..... Pretty sure all cells in the world that aren't complete junk already have this, and that is NOT a safety circuit (unless it's in the cell, like Ypedal pointed out)
 
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