Tabless design cylindrical cells tests

At Vapcell (Shenzhen Vapcell Technology Co., Ltd.) from my experience they have the most up-to-date information on their Alibaba store and it's also probably the most seamless way how to order from there as well. Here is the link https://www.alibaba.com/product-det...tml?spm=a2700.shop_pl.41413.19.769c7121O4V8Ne

Just click on "Chat now" and write that you are interested in a particular cell, a salesperson will contact you thru the Alibaba Messages chat and make a quote for cells and calculate shipping cost for you. The minimal order amount is usually 10pcs.
 
Seems like the 50PLs on market are MP too. Interesting! JP50s starting sampling earlier this year, so we'll probably start seeing those too.

LG will be joining Samsung in launching a tabless cell sometime late this year/early next from what I hear. Wonder if Panasonic will try to get one out too?
 
Hey, just doing a PSA. I went to grab some JP30s from Shenzhen on Alibaba. When I inquired about the grade they told me "so far we only have grade B. don't have grade A". This is despite the JP30 description clearly showing grade A. When asked about the difference between grade A and B I was told: "A is quite stable and good for battery pack, Grade B is only good for single device use". I assume they mean devices that use a single cell.

In this case does grade B mean larger than acceptable variance in capacity by the manufacturer?
Does anyone know a good supplier of JP30s with grade A cells?
 

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jonjonmia said:
In this case does grade B mean larger than acceptable variance in capacity by the manufacturer?
Does anyone know a good supplier of JP30s with grade A cells?
Click to expand...
Each grade has its own acceptable level of capacity variance. So ”Grade B” doesn’t have a larger than acceptable variance for the manufacture, just larger than what could make it “Grade A”. It could be perfectly acceptable for a “Grade B” cell and millions upon millions of them are used successfully in products every year. IMO we buy huge numbers of them and never notice they’re not “Grade A” because we have actually never used one before for that cell model.

Lower grades do mean greater capacity variance but that’s typically not visible until down below 3.0V/cell (or even lower). Greater differences in internal resistance can mean greater cell-to-cell current flow within pack p-groups and/or greater differences in voltage sag under load for the p-groups but typically not a big concern. Greater differences in self-discharge rates can result in more work for the BMS to keep the pack balanced but that isn’t much of an issue unless the pack is stored for long periods of time.

So, lower grades (not the real junk) can mean the cells are “worse” but many people wouldn’t even notice the difference between top grade cells and a bit below that. There’s just not much difference between typical “Grade A” and “Grade B” cells.

IMO, there are no top grade JP30’s available yet. Like any hot new cell, IMO 100% of them are being bought up by the big customers and only lower grades are available to these resellers. We’ll either have to wait until the big customers sell off excess inventory after a production run of their product or demand drops and higher grade JP30’s can be directly purchased from Ampace.
 
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On the topic of bleeding edge cells, does anyone here know if some manufacturer is planning to make direct path tabless cells? I've only seen CALB make an announcement on this back in 2023 for their large format cylindrical cells. Since then, nothing.

Direct path tabless cells, otherwise known as u-tab interconnects, are just normal tabless cells with dedicated current paths for the negative electrode to completely bypass the canister as a conductor and should be the last big interconnect gain for a while.

Source: https://www.notebookcheck.net/CALB-...-density-and-10-minute-charging.706566.0.html
 
BlueSwordM said:
On the topic of bleeding edge cells, does anyone here know if some manufacturer is planning to make direct path tabless cells? I've only seen CALB make an announcement on this back in 2023 for their large format cylindrical cells. Since then, nothing.
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This might have been part of CATL’s lawsuits against CALB, which CALB pretty much lost (but are appealing), and so the tech is not being used by others? And CATL might have thought it just wasn’t worth the expense of finishing development and modding their production line(s) for the small number of customers willing to modify their products (or pack assembly practices) to use that new contact arrangement?

Nothing on CALB‘s web site either…which would be strange if they were still moving forward with it.

It just seems that something would have otherwise popped up…it’s been two years.. 🤔🤷‍♂️
 
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BlueSwordM said:
Direct path tabless cells, otherwise known as u-tab interconnects, are just normal tabless cells with dedicated current paths for the negative electrode to completely bypass the canister as a conductor and should be the last big interconnect gain for a while.
Click to expand...
I’m thinking we still need to see the “tabless” 18650’s and 21700’s actually go tabless. All of them still have a cathode tab (from current collector plate to the cell contact) and the BAK 45D even has an anode tab.
 
22426be7-7c20-44b5-950d-568e54cf5f00.jpeg

What about this other new cell? Anybody hear of this one? I just order 5 samples to test.

The numbers looks impressive, charging capabilities and cycle life. We need to see if is true.

Reliance INR21700-RS50 Specifications

Summary
Cell Type: INR21700-RS50
Nominal Voltage: 3.6V
Nominal Capacity: 4950mAh (minimum)
Max Continuous Discharge: 70A (with 80°C temperature cutoff)
Max Continuous Charge: 15A
Standard Charge: 2.5A (0.5C) CCCV to 4.2V, 100mA cutoff
Fast Charge: 15A (3C) CCCV to 4.2V
Impedance (ACIR @1kHz): ≤4.0 mΩ
Discharge Cutoff Voltage: 2.5V
Charge Temperature Range: 0°C to 60°C
Discharge Temperature Range: -40°C to 80°C
Weight: ≤67g
Dimensions (Max): Ø 21.35mm x 70.30mm

Storage Temperature:
1 year: -20°C to 25°C
3 months: -20°C to 45°C
1 month: -20°C to 60°C

Cycle Life
Test Condition: 25°C, 8A charge / 40A discharge
Result: 400 cycles with ≥60% capacity retention

Test Condition: 25°C, 15A charge / 30A discharge
Result: 400 cycles with ≥60% capacity retention

Test Condition: 0°C, 8A charge / 10A discharge
Result: 200 cycles with ≥80% capacity retention

Test Condition: -10°C, 3A charge / 10A discharge
Result: 50 cycles with ≥80% capacity retention (Note: manufacturer does not guarantee performance/safety for charging below 0°C)
 

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ZEUS-FL said:
View attachment 370931

What about this other new cell? Anybody hear of this one? I just order 5 samples to test.

The numbers looks impressive, charging capabilities and cycle life. We need to see if is true.

Reliance INR21700-RS50 Specifications
Click to expand...
What was the price for those samples, curious how it compares per cell to the all mighty 50PL
 
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