52V 21700 Cells When?

Ebiker33

Well-Known Member
The new Archon motor is the best of the best, the only thing that can make it better is a stronger power source, 52V is about as high as we are going to go for this type of bike, after this it has to be cell technology for higher outputs for bursting torque outputs. Here is the information why.

21700 Vs 18650 Choice Fuels Cordless Advancement
Around here, we primarily focus on the tools and gear surrounding the construction industry. That makes the 21700 vs 18650 conversation incredibly relevant to us, but these lithium-ion power sources reach far beyond the latest cordless tools. They’re driving innovation in Teslas, hoverboards, the vaping community, and so much more.

21700 Vs 18650: What do the Numbers Mean?
21700, 18650, 20700 and others simply refer to the physical size of the lithium-ion cell. For 18650, it’s an 18 mm diameter x 65 mm length. 21700 is 21 mm x 70 mm. While the explanation is simple, the difference is profound. It’s easy to see with a quick volume calculation.

18650

3.14(9 x 9)(65) = 16,532 cubic mm

21700

3.14(10.5 x 10.5)(70) = 24,233 cubic mm


An extra 5 mm of length and 3 mm of diameter gives us 47% more volume. That’s a little more than 7,700 cubic mm of space to pack with energy-delivering anode, cathode, and electrolyte material.

More Capacity = More Runtime


The most obvious benefit of going with 21700 vs 18650 is that the extra density means there’s more available energy in them to run your tools and gear longer. Batteries that we see using 18650 cells for power tools range from 1.5Ah (1500mAh) to 3.0Ah (3000mAh) in each cell. 18650 cells on the higher end of that scale have reported issues and 2.5Ah (2500 mAh) cells seem to be where most manufacturers settle at the top.

On the other hand, 21700 cells start around 3.0Ah (3000mAh) and go up to 4.0Ah (4000mAh) for power tool batteries. It’s why we see compact (1P) packs that have 3Ah or 4Ah designations all the way up to 12Ah (3P) big boys.

From the perspective of power tools, you’re looking at a 50%–100% runtime gain over today’s standard 18650 packs. Outside the power tool industry, some of these cells reach 5.0 Ah (5000mAh).

Current Standard Power Tool Batteries (based on 18V/20V max batteries)
18650
  • Compact 1P Battery: 2.0Ah–3.0Ah (36 Wh–54 Wh)
  • General Purpose 2P Battery: 4.0Ah–6.0Ah (72 Wh to 108 Wh)
  • High Capacity 3P Battery: 9.0Ah (162Wh)
21700
  • Compact 1P Battery: 3.0Ah–4.0Ah (54 Wh–72Wh)
  • General Purpose 2P Battery: 6.0Ah–8.0Ah (108 Wh–144 Wh)
  • High Capacity 3P Battery: 9Ah–12Ah (162 Wh–216 Wh)

More Power
Batteries like Bosch’s Core18V, Milwaukee’s M18 High Output, and Metabo’s LiHD packs do more than just take advantage of longer runtime. They improve their packs’ cooling abilities and build them with better materials that reduce resistance (Ohms). The result is a battery with much greater power available.

Take Bosch, for example. Their standard 18V batteries can produce up to 800 watts of power output. When they upgraded to Core18V, it went up to 1440 watts—an 80% power increase! Other brands report significant power gains as well.

It gives them the ability to produce cordless tools that we didn’t think we’d ever see without a cord just a few years ago. And many of them are outperforming their corded counterparts now.

Power tools are hardly the end product. Outdoor power equipment for lawn care and landscaping, battery-powered inverters, and whispers of gas-powered construction equipment are all starting to have cordless options thanks to 21700 cells.

This is what 40V 21700 cells is going to do for power tools.

 
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pushkar

Well-Known Member
We have test batteries like most vendors do. The limitation is that current cases are not designed for that dimension.

I have something special planned for those batteries when there are enough molds for us to choose from. There’s a feature with 21700 (and HG2) that will be crazy great.

At the moment - realistically- we are around 12-15 months away from widespread availability to match the 18650 17ah capacity. so we don’t gain anything in the short run but some of thereally cool things we can put in for the 30Q and HG2 cells.
 
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Timpo

Well-Known Member
Here, I found it.

If you don't know what Grin Technology is, they're a Canadian ebike tuner.
They're well known for their products such as GMAC motor, Phaserunner controller, Satiator charger, Cycle Analyst display, and of course, 21700 pack.
 

JRA

Well-Known Member
I have 3 Hailong (shark) type 21700 cell batteries. I needed a new battery to replace an 18650 3.5A cell battery a few years ago and was thinking the 21700 cells were worth tracking down and sourced one from China via some googling. It is a 52v but have since gone to 48v because there really isn’t much performance gain as far as I can tell.

1) 52v 15ah 5.0A cells that is almost 2 yrs. old

1) 48v 18ah 4.8A cells 1yr.old

1) 48v 12ah 5.0A cells 6 months old

Have a 48v 5.0cell on the way for a build

There is a case made that will fit the 21700 cells and they can be stuffed in a hailong also as one of mine is.

Several big name manufacturers already use internal 21700 cells but for some reason they don’t do much to advertise the fact.

There a some marginal performance gains with the larger cells especially at the top 40% of the charge.

I use a Satiator charger exclusively that will charge up to 7A if I have the need but primarily charge @ 4A. I don’t mess around with anything other than a full charge but do not store at that.

Costs were equivalent to 18650 quality type cell batteries average cost of $500/.

You will see them used more and quite frankly am surprised it hasn’t happened yet.
D0EDEA74-6FD5-4E0E-842F-2A83A5FB015B.jpeg


HL and new mould case above
 

Ebiker33

Well-Known Member
Here, I found it.

If you don't know what Grin Technology is, they're a Canadian ebike tuner.
They're well known for their products such as GMAC motor, Phaserunner controller, Satiator charger, Cycle Analyst display, and of course, 21700 pack.
Very interesting, here is what they say

72V (20s) 9.5 Ah Downtube battery using high power 21700A cells from Panasonic. Uses 30A continuous BMS circuit and is an ideal pack for combining with the Phaserunner 72V Grinfineon controller to produce fast and powerful ebike projects that don't require extensive range.
 

pushkar

Well-Known Member
Yeah. . this battery is only 72*9 = 650wh regardless of what the underlying cells are.
And if you are discharging at 30A ... or say 20 A ... then you are using a fair bit of the battery. this will go quick.
 

Ebiker33

Well-Known Member
Yeah. . this battery is only 72*9 = 650wh regardless of what the underlying cells are.
And if you are discharging at 30A ... or say 20 A ... then you are using a fair bit of the battery. this will go quick.
This battery would have super short run time agreed, but wouldn't this paired with a 25A controller give you 1800W burst power?
 

pushkar

Well-Known Member
Probably would. Yeah. But 20S3p pack won’t be able to sustain max wattage beyond a minute or two max.

someone with more battery knowledge can comment here.
That being said the question is about range. That is low in any case because of low capacity coupled with high discharge rates.
 

Ebiker33

Well-Known Member
Probably would. Yeah. But 20S3p pack won’t be able to sustain max wattage beyond a minute or two max.

someone with more battery knowledge can comment here.
That being said the question is about range. That is low in any case because of low capacity coupled with high discharge rates.
In the power tool industry the battery is communicating to the motor and increasing and decreasing power output as needed to increase life, for example I posted that video of the Makita 40V.
If you were to take a cordless drill and drill only a 1/8" hole in soft wood the drill would tell the battery I don't need much power for this job, transversely if you were using it for a 1" hole saw in steel it's going to ask the battery for much more power.
Is that type of thing happening in the Ebike industry yet between motors and batteries, an example would be riding on flat asphalt verses a rocky 20% grade climb.
 

pushkar

Well-Known Member
At the moment, the motor is pulling primarily based on assist needed. Some motors can calibrate based on battery voltage too (e.g .when nearing a cutoff the motor stops pulling any current).
The BMS (which resides 'in' the battery pack) determines how many amps to send based on the battery condition. This is very common and I suspect any non-integrated system (bafang / Brose / yamaha / Shimano) will have the same "power only" setup.

I dont know if the motor has the intelligence to calibrate based on type of trail. That is currently being somewhat manually enforced using ride profiles (cargo / trail / commuting etc) - we are forcing the motor to behave in a particular way.

I am sure things will improve over time. That being said I dont know if adding that intelligence to the motor / battery thing will mean much. Look at the whole "regen" thing - realistically it adds 5% (if that) to a ride. It does "something".. but if you are riding with a 1600Wh / 1800Wh pack, is it meaningful to a rider? IMO perhaps not.
 

CityExplorer

Active Member
If we get 1600Wh packs then we are set!! :)
Realistically I think we need the next battery tech for a weight reduction, EUCs not just pushing 3800Wh batteries from a custom build to one about to be released.I think they have now hit the limit for them, but a bike is a lot heavier so hits a realistic weight limit earlier. Still if the packs were setup like pannier bags you could get some wicked range, but a less that idea setup. And if people start demanding integrated batteries then the problem is tougher. External batteries are so much better for long term maintenance and upgrading, but some don't care if their bike is not good for 5 years, let alone 10, 15, or 20.