what makes you say that? Liion lasts for as long as you want if you treat the battery well. look at teslas 8year battery warranty …
problem might be that people always use very small batteries that live on their limit. if you have flat charge/discharge cycles, leave & store the battery around its nominal voltage whenever possible and make sure it doesnt heat up to much, it will last forever.
my first evolve battery 1 year ago probably saw 200 cycles and recently, the guy who bought the battery, sent me a gps log that showed that the battery basically had its first day capacity.
Most 18650 Li-ion cells have about 70% capacity after 250 cycles. They may work to 1000 cycles, as you’ve said capacity would be severely reduced, probably more so than 50%. However, the test environment Samsung tests with discharges to 2.5v which is a lot lower than what most people normally discharge to, so you can probably make 18650’s last a very long time given proper care and treatment.
I wonder if there’s been any tests done to cells like these that discharge to a safer voltage like 3.0-3.2
As for battery, BMS low voltage cut off occurs when a cell hits 2.9v
However, on the optional LCD that comes with battery, 0% is displayed when cells are around 3.2v
And moreover, I recommend if your ESC’s have a Low voltage cut-off to set it at 3.5v… That is the setting I ship all my ESC’s with and will keep both li-ion and lipos healthy for a long time. My MultiStar Lipos have over 200 Cycles and they still give me the same range as first day!
noone in their right mind would charge a battery to 4.2 and discharge to 2.5V. these cycles and capacity drops are NOT what you can expect in a hobby environment where you probably try to keep your batteries happy.
look at teslas 8year warranty is all Ill say here - they have a massive battery and use it within fairly flat charge % discharge states with low current per cell that keeps it nice and cool. and thats basically all there is to the “secret of eternal liion battery life”.
and thats plain wrong in my eyes! I would argue that if your batterie isnt at least at 90%+ after 200 cycles, you probably didnt treat it very well.
always keep tesla in mind: […] the 85 kWh Model S, our most popular model by far, now has an 8 year, infinite mile warranty on both the battery pack and drive unit.
That’s why I added the line right after that which explains that what I’ve said are factory test conditions for these cells. Datasheets are important and give an idea of bare minimum performance of quality cells!
I think people are getting very efficient in reading things nowadays - so much to read, so little time - so they go for the essentials and what “sticked” of your post was “200 cycles, 70%, 1000 cycles 50%”. Im pretty convinced that the yaddayadda about factory test cycles is something that wont reach many people when the skip through this thread, or, worst case, its stored as “200 cycles 70%, confirmed by manufacturer samsung”.
I just wanted to make sure that the “soak things up in 10seconds bottom line is not 200cycles 70%”, but that if you treat your battery well, it will last you a very long time!
@appelton the freerc ones feel the best and I feel have the higher performance. lofty is a close second. the hobbytech get slightly hotter than the rest and are slower since the kv is lower but i don’t feel too much torque benefits for the lower kv.
@willpark16 battery on single 250kv has crazy range! i’ve got over 20mile ride on a single charge. my feet were numb! disclaimer I kicked off ever time i had to start, and keep relatively low speeds around 15-20mph
I usually use dual though as I prefer the even power distribution when accelerating or stopping.
You shouldn’t.
I’ve used the same ESC now for almost a year with different batteries and motors I have gotten.
I’ve used it for range and speed tests. The hottest my ESC has ever gotten is about 140F. That was none stop full throttle up parking garages and braking down with single hub motor.
I was intentionally trying to heat it up as much as possible as well as test regen, and it handled everything like a champ.
I have also hit 40+ mph but only on the dual esc and that one does not heat up at all. nothing i have tried to do on it has made it my dual motor esc break a sweat. Also i can only go 40+ for about 2-3 seconds, i start to run out of straight road.
I do not like to go over 30 with single motors because of the uneven brake/acceleration, can cause nasty speed wobbles
