So I’m looking at alternatives to the 18650s, as I either get high amps and low capacity or high capacity and low amps. To get both, you need a massive pack. So I found these 26650 cells which are rated to 50 amps continuous and have 5000 mAh!I can fit a 12s3p of 26650s in the same space as a 12s4p with 18650s (I build my decks to have 27mm of space inside in height anyways). So here’s the comparison:
18650 LG HE2:
12s4p
80 amps continuous
504 Wh
26650 BASEN IMR:
12s3p
150 amps continuous
756 Wh
Basically, I could get almost double the max continuous amps, and 1.5 times the range. And it would fit in my board as is right now. But this seems too good to be true… Is it? Am I over looking anything? Has anyone tried these cells before? Thoughts?
I would not not trust those batteries on eBay.
They look like counterfeit.
The Basen black 26650 is a 4500 mah battery with 60a pulse and 25a continuous.
I built a 10s2p pack with them and it worked fine on flat ground but the voltage sagged a lot going up hills.
So are there any 26650 cells out there with real continuous ratings that are more than 25a?
Looking through what Mooch said about 26650s, and he seems to think they are all vastly over exaggerated… I’m looking for 100 amp con or higher for the whole pack, as I’m trying to reduce sag…
Not sure what the measured discharge amps are, but they are higher, with the cost in capacity at only 2500mAh.
Digging further - this looks like an excellent cell for us, if you do some in parallel for better mileage.
Mooch:
[quote]This is an extraordinary cell that I am rating at 30A. My maximum vaping amps (MVA) rating is 70A. The two cells I received from EnerCig and the two from Nkon appear to have come from the same batch.
The datasheet has a “maximum continuous discharge” rating of 70A in the
datasheet. But at that temperature, about 85°C, the cell will have a
significantly reduced cycle life. This rating is an absolute maximum,
not a level you should operate the battery at for every cycle. To allow
direct comparison against other batteries I am rating this cell at a
level, 30A continuous, which limits the temperature to 60°C to ensure
good cycle life. Above this temperature the cell’s aging accelerates
significantly. The cell can easily be pulsed at levels above 80A though.
This cell’s lithium-ferrous-phosphate (LFP) chemistry is the safest of
the Li-Ion chemistries we use. While this should never be used as an
excuse to do so, these A123’s can take a lot of abuse before going into
thermal runaway. If they do go into runaway their reaction isn’t as
violent as the other chemistries.
The voltage of this cell is very steady for most of the discharge, very
similar to LiPo’s. This is great for unregulated/mechanical mod users. The iJoy 4200mAh 26650 is a better choice for vaping at up to about 40A though.[/quote]
So it seems like 26650’s might not be the solution after all… I wouldn’t really gain anything and maybe loose range since I would be at 7500 mah with the A123 instead of 10000 mah with the 18650s.
I can agree with @Namasaki , I have a Basen 6s2p pack and while the range is great on flat, of course it does have a lot of sag. Maybe 3p might be okay at 12s, but likely you will still have some sag.
I haven’t fully tested the range, but on this 6s2p I feel like I can get 15-20km.
My daily commute is 9kms and depending on if I do a route with hills or not, I have between 50-70% when I’m back home.
Basically I think it’s safe to assume that you can only get the amount of amps as an 18650 from these cells. So if its the same space as 12s4p, go with that for less sag.
I think voltage sag is one of the main challenges we face with esk8 design.
Even my 10s 60C Lipo pack capable of 300a cont sags a little when going up hills. Still, much less than anything else I’ve tried so far.
Accelerating up a 15% grade, total voltage only drops around 1 volt. That’s only 1/10 volt per cell.
One is riding great (the perfectly balanced), haven’t done extensive testing with the other yet because it’s been raining on/off in the bay area recently. Gets about 4.5 miles of range (1000mah/mile). Both of my packs are with the 4500mah 26650s