Tabless design cylindrical cells tests

Damn 6.5ah and 4C? super impressive for ebike use.
Just released though so i figure us hobbyists aren't getting them for a moment.

Any other battery makers reaching that kind of density today w/o going to semi solid state etc
 
BatteryMooch said:
We can‘t use max temps and/or a single IR number, AC or DC, to compare cells like that.

The DC IR is only the ohmic resistance at whatever temp it was measured at and doesn’t take into account the different other electro-chemical equivalent (AC) resistances that can have a huge effect at different temps.

The standard AC IR measured at 1kHz is just a small sample of, very roughly, the condition at that temp of the electrolyte. It will change in different ways for different cells at different times.

Neither resistance reading can be used to make any judgements or come to any detailed conclusions regarding different cells. Just compare the performance under different loads and the resulting cycle life.

To a degree, max temp doean’t mean much either as different cells have different levels of tolerance to higher temps and, in fact, may be designed to run a little hotter to increase electrochemical efficiency and reduce voltage sag a bit.

We all want this frustrating “it depends” stuff to be distilled down to one or two easy to measure and judge things (especially those who are testing!) but it’s often just not possible.
Click to expand...
Great points. In fact, you just reminded me of an old paper about temperature-activated electrolytes I read a few years ago.
They played with additives that greatly reduce the viscosity of the electrolyte once a certain temperature threshold is reached, leading to *higher* efficiency than an otherwise similar cell at high temperatures.

I wonder if that's what certain cell manufacturers are playing with now, or if they're taking into account that many cylindrical cell packs aren't actively cooled outside of cars, so they design their cells and electrolyte to behave best at high temperatures.

The performance graphs we see at 20-25C may not be the same at 40-45C.

In the end, what matters is that the most Wh are delivered in the smallest period of time when measuring power density.
 
neptronix said:
Damn 6.5ah and 4C? super impressive for ebike use.
Just released though so i figure us hobbyists aren't getting them for a moment.

Any other battery makers reaching that kind of density today w/o going to semi solid state etc
Click to expand...
Well, since big manufacturers are getting the cells in Q4-2025 and "small" ones in Q1-2026, I'm expecting the BAK 7000mAh 21700 to come relatively soon.
 
BlueSwordM said:
I wonder if that's what certain cell manufacturers are playing with now, or if they're taking into account that many cylindrical cell packs aren't actively cooled outside of cars, so they design their cells and electrolyte to behave best at high temperatures.

The performance graphs we see at 20-25C may not be the same at 40-45C.
Click to expand...
For the large prismatics and pouch cells designed for EV use I wouldn’t be surprised that they were optimized for a not-room-temp range. But IMO that isn’t being done for the small round cells we use.

For those I‘m thinking they go for the best performance they can get over a wide temp range due to the large number of applications for those cells, perhaps with some additional work on low temp performance from companies like Moli.

I could be completely wrong though.🙂
 
Last edited:
BatteryMooch said:
We can‘t use max temps and/or a single IR number, AC or DC, to compare cells like that.

..

To a degree, max temp doean’t mean much either as different cells have different levels of tolerance to higher temps and, in fact, may be designed to run a little hotter to increase electrochemical efficiency and reduce voltage sag a bit.

We all want this frustrating “it depends” stuff to be distilled down to one or two easy to measure and judge things (especially those who are testing!) but it’s often just not possible.
Click to expand...
I would just like to add some specific data to support this.

For example, my table data only shows the difference in FC (with ventilator) and AC (without ventilator) cell final temperatures, but I do not include into the tab the difference in discharged capacity@energy, which is typically 2-3% in favor of AC (i.e., discharge is finished at significantly higher final temperature), where this difference is already apparent from 1C-rate.
 
@Pajda @BatteryMooch Apparently, you peeps are not great battery testing sources:
https://www.reddit.com/r/electricvehicles/comments/1mkx6dj/_/n7z5i6e

https://www.reddit.com/r/electricvehicles/comments/1mpflpq/_/n8prnik

I always find it funny when I provide sources with the full testing methodology, a billion high quality graphs, IR + temp graphs over time, etc, and yet, they aren't convinced.

You spend so much time and effort on these things and I could never be thankful enough for what you've given the community.
 
BatteryMooch said:
@BlueSwordM, thank you for your kind words!
He seems quite concerned about range but zero mention of pack Wh, configuration, etc…all the things you actually need to know to compare their battery packs, range, cells, etc.

Otherwise we can just stuff the trunk and back seat with a pile of cells and have huge range. 😂
Click to expand...
Lucid engineers claim that the Panasonic cells used in the Lucid Gravity are ~300wh/kg, and presumably they're fairly power-dense too.

Pretty surprising considering how far behind Panasonic's publically available cells are compared to the Chinese competition.
 
Dan93 said:
Lucid engineers claim that the Panasonic cells used in the Lucid Gravity are ~300wh/kg, and presumably they're fairly power-dense too.

Pretty surprising considering how far behind Panasonic's publically available cells are compared to the Chinese competition.
Click to expand...
inb4 they're 300Wh/kg tabless cells.

However, I'm expecting them to be closer to Molicel PXXB cells, using multiple tabs and high conductivity components to avoid having to retool their assembly lines.
 
I just got 10 samples of EVE 30PL production cell.
I have already shipped 4 to Mooch expedite shipping. I will start testing against the Ampace JP30 cell.

Data sheet included !!!


IMG_4853.jpeg


IMG_4860.jpeg
View attachment IMG_4854.jpeg
 

Attachments

  • IMG_4853.jpeg
    IMG_4853.jpeg
    1.5 MB · Views: 22
  • IMG_4859.jpeg
    IMG_4859.jpeg
    2.2 MB · Views: 22
  • IMG_4858.jpeg
    IMG_4858.jpeg
    1.4 MB · Views: 20
  • IMG_4856.jpeg
    3.4 MB · Views: 11
  • IMG_4854.jpeg
    4.4 MB · Views: 8
  • IMG_4856.jpeg
    3.4 MB · Views: 8
  • PBRI-INR18650 30PL-D06-03-《EVE INR18650-30PL SPEC.》-V2-2025.3.27.pdf
    427 KB · Views: 25
Last edited:
BlueSwordM said:
Oh, I can tell this is one of their newest cells.
4C max chargin speeds, double what the EVE 50PL is rated at.
Click to expand...

The 30PL and 50PL reached full production at essentially the same time.

IMO we can‘t use C-ratings here. The charge rate for the 30PL is only 2A higher than the 50PL’s and that can be solely due to physical cell differences (like smaller radius for heat transfer to the case).

And higher capacity cells often have to scale back current handling due to higher ohmic resistance so charge ratings can’t always scale with capacity. IMO we can (fairly) compare charge rates only for cells of the same size and roughly same capacity.

Okay, sure, we can compare anything we want. 😂
But IMO we can’t say that the 30PL is a later generation cell just because of a higher charge current rating, especially considering the timing of its release. A teardown will be interesting though and I’ll have that for my patrons before the weekend.
 
Last edited:
EVE just released a new datasheet for the 30PL cell, dated June. The previous version was from March.
In this update, the maximum discharge rate was increased from 50A to 60A, the maximum charge rate was reduced from 14.5A 12A to 9A, and they added a specification from 400 to 500 lifecycle at 60%.

Thanks Mooch for pointing out the charging current error. I was mixing with JP30P1 cells that are rated 14.5A.

1757528665710.png

diy500amp.com

EVE 30PL 18650 3000mAh 60A Battery Cell - Tabless

EVE 30PL 18650 3000mAh 60A tabless cell – the most powerful 18650 on the market. 60A continuous, 140A burst, low IR, and perfect for high-performance e-bikes, scooters, drones, and custom packs.
diy500amp.com
 
Last edited:
You must log in or register to reply here.

Similar threads

Pajda
    • Like
Molicel P50B variable charge-rate cycle life test
2
Replies
37
Views
7,334
Gika
Gika
Pajda
    • Like
Cycle life tests of mixed-technology cells
Replies
8
Views
4,526
Pajda
Pajda
Pajda
    • Like
Cycle life tests of High Energy density cylindrical cells
8 9 10 11 12
Replies
280
Views
90,428
freesty
F
Pajda
    • Like
Calendar ageing tests of mixed cylindrical cells
2
Replies
31
Views
7,188
Pajda
Pajda
Pajda
    • Like
Cycle life tests of High Power density cylindrical cells
2 3 4 5 6
Replies
126
Views
41,654
riba2233
riba2233
Back
Top