About what?
Ur not using my beloved Kickstarter.
Hahahha! sorry mate, but in the long term kickstarter is a bigger hassle than what were using now.
Ok well I need to get to bed before the Aussies get on. Canāt have it happen 2 nights in a row.
I think thereās about 5% of the cellās energy left after going lower than 3.6 or maybe it was 3.5. I like 3.6 to 4.1. ā¦but then I always canāt help myself and do 4.2!
This should provide a better idea.
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You can check this discharge curve too
Take a look at the 10-15A discharge curve. Once you use about 1.25 amp hour (50%) of the 2.5amp hours in a 18650 cell you have about 3.4v on the cell. However, due to voltage sag this is probably closer to 3.6v. Since the graph is non-linear the cells deplete rapid when voltage falls even lower, so it wouldnāt read 50% on a voltmeter.
That said, 3.6 is about 50% of the capacity of the battery, but wonāt necessarily read 50% on a voltmeter. You should still have a bit of charge after nominal voltage though, more than 5%.
It depends on the chemistry. Iāve seen differnet numbers.
http://helifreak.com/showthread.php?t=333661
Iāll find lipo specifically and post it. Iāve seen 3.6= 5%
Keep in mind lipo nominal voltage is usually 3.7v, they also have different properties. I speak mainly about 18650 cells because I donāt and will never use lipos myself.
Thatās lipo
- I used a 60 mAH ultra-thin lithium polymer battery.
You donāt need to show me li-ion, Iāve already posted it above. This is a discharge test by Samsung themselves.
Hereās a bunch of Li-ion. They vary.
And then it depends when u test the voltage
Right, though your example is also 3.7v nominal and are chinese cells. Iām talking about quality cells such as those found in the space cell, which was our original discussion point.
Last link is three Panasonic and a Sanyo
Ur graph shows the cells at hard draw ,while being drawn from. The resting voltage is most often the reference
Although it does show a way lower voltsge than any I come across. 1 amp isnāt really a hard draw
You can also see in the Panasonic cells that you have about 40% at 3.6v
Right u are thereās more energy at lower voltages in the Li-ion than the lipo.
If you read his Kickstarter carefully, he never says heās using a 12s battery. He just says that it has 12 Lithium ion cells. He makes the following claims:
20 mph top speed 2200w motor 12 cell li-ion battery with BMS 25+ miles range $699 price
And honestly, that probably can be doneā¦ If you were to use the biggest li-ion cells available and configure them 6s2p. There are a couple oddball 32650 cells out of China that have 6000 mAh capacity at 10 C rating. String em together at 6s2p and you have a 275 WH battery that can discharge 20A continuous. Limit the amp draw with the BMS, pair it with that tacon 245kv motor with proper gearing and you got your 25 miles range / ~20 mph top speed in ideal conditions. The raw materials wouldnāt be that expensive either, you could use a cheap 6s car esc with a little programming.
The problem is that it wonāt have any climbing power and the cells will have a short life if you are constantly pulling the max rated discharge. Itāll fail with bigger riders and hills. The ESC wonāt allow for modifications. Kinda like the Yuneec & benchwheel boards, itāll work only in certain conditions and I doubt youāll get decent customer support from this high school kid in Miami.
I think you mean 10A rating not 10C rating. 10C would be 60amp discharge * 2P for 120A discharge. even with 275 watt hours thereās no way itāll make it 25 miles, not even close.
Yeah 10A continuous discharge per cell, my mistake.
Iām sure that there are lighter riders who can take a single-drive, 275Wh board 25 miles on flat land if they are cruising at a constant speed where rpms are near peak efficiency. Of course, most people would pull more amps just to get up to that speed.
Real world range would obviously be lower.