Tabless design cylindrical cells tests

[OrKaN]

Around 90kW from the battery

I would start balancing only in the upper SOC area. I balance only above 3,9V, but these are active balancers with 1A and 2A on my battery packs.

On October 11th and 12th, I'll be doing a drag race, probably my last race of the year. After that, I'll be installing a 4A active balancer in the winter. I won't be able to test the cells extensively during the drag race, but I'm very curious to see how much of a difference it makes between the old battery pack and the new one.

 

[amberwolf]

Unfortunately, I've just realized that I'm not allowed to upload a video file directly here. However, I have videos on my YouTube channel not of the new chassis and battery pack, but of the old chassis and with the old battery pack.

An easy way to fix that is to put your videos on your YT channel and then post the link here. The forum can display them in the post directly.

 

[OrKaN]

An easy way to fix that is to put your videos on your YT channel and then post the link here. The forum can display them in the post directly.

Unfortunately, I haven't uploaded any videos of the new go-kart yet. Unfortunately, only videos with the old battery pack and chassis are available on YouTube. Here's an old 1/4 mil. video.

 

[Pajda]

Small update

Update:
- more cycles in separated 20A discharge chart in the first post,
- Reliance RS50 sample finally started

 

[BlueSwordM]

Small update

Update:
- more cycles in separated 20A discharge chart in the first post,
- Reliance RS50 sample finally started

Wow, the EVE50PL is a monster.
It'll get over 1000 cycles down to 82.5%, and those were the earliest preproduction units with a min capacity of 4800mAh.

For reference, the latest batches have the highest capacity with a minimum of 4980mAh.

 

[ZEUS-FL]

First results from the TENPOWER 50XG.
I need to clarify my tester at 50A after 3.1V decreases the current and the result will not be 100% accurate but we can have a VERY good idea. This cell is something else. Just check the results. AC IR 2.3

 

[Elios.pk]

First results from the TENPOWER 50XG.

Is this a pre-production engineering sample or is this cell already mass produced or at least available to buy for us ?

Seems like a real 50S killer. Tenpower cell's are also often more cost-effective than competitors

 

[ZEUS-FL]

I have confirmation is in mass production and will be ready to sell by the end of this month. I am waiting for Mooch results.

 

[DPR]

I tested the EVE 50PL sent by ZEUS-FL and I was impressed by the result. At 10C ( 50A ) and minimal air flow I was capable discharging these from 100-0% and got 4750mAh(10C) capacity out of the standard 4900mA at C/5.

View attachment 369972​

I also got interesting ACIR and DCIR results. ACIr 2,88miliohms at 50% SOC and 22 degree C You can compare with the P45B


DCIR curve of 5 samples vs SOC @23c
View attachment 369977

What were the conditions of the DCIR measurements? 3C discharge for 1s?

 

[DPR]

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.

Not exactly. ACIR at 1 kHz mostly represents the ohmic resistance and is typically measured during manufacturing to screen out bad cells. DCIR, in addition to the ohmic resistance, includes charge-transfer, SEI, and diffusion resistances. DCIR depends on many parameters, such as SOC, temperature, current, and pulse duration, because different resistance components (CT, SEI, etc.) dominate under different conditions.

 

[BatteryMooch]

Not exactly. ACIR at 1 kHz mostly represents the ohmic resistance and is typically measured during manufacturing to screen out bad cells. DCIR, in addition to the ohmic resistance, includes charge-transfer, SEI, and diffusion resistances. DCIR depends on many parameters, such as SOC, temperature, current, and pulse duration, because different resistance components (CT, SEI, etc.) dominate under different conditions.

The ACIR is indeed mostly ohmic resistance but the majority of that is from the electrolyte. To simply my earlier response I just mentioned the biggest contributor. Thank you for expanding on that!

And thanks for adding a discussion of DCIR and mentioning it can include different resistances. You only briefly mentioned something very important though, pulse duration. The DCIR spec I include in my testing is done with a pulse only a few mS long and so only includes the ohmic resistance of the cell’s materials. This allows for quick calculation of the initial instantaneous voltage sag.

Other DCIR testing standards require longer pulse lengths, sometimes combined with a charge pulse. For anyone comparing cells note that the DCIR spec can change a lot depending on the pulse type/length. Definitely confirm that the same pulse was used for all cells.

I know you know this. Only mentioned for others as part of your broader discussion of the resistances involved.

 

[BlueSwordM]

I have confirmation is in mass production and will be ready to sell by the end of this month.

I wonder if Molicel's collaboration is Tenpower is paying dividends to then.

 

[BatteryMooch]

I wonder if Molicel's collaboration is Tenpower is paying dividends to then.

I can’t imagine them doing a collab unless they both saw real benefits to it. The M65A seems like it’s going to be a great start but we might not see the full effect of all this for years.

 

[Bengy22]

First results from the TENPOWER 50XG.
I need to clarify my tester at 50A after 3.1V decreases the current and the result will not be 100% accurate but we can have a VERY good idea. This cell is something else. Just check the results. AC IR 2.3

Wow really good looking first results! Thank you for sending them over to Mooch, I also cannot wait to see the results he posts!

 

[Bengy22]

I haven't seen anyone mention it on here but earlier in the year Reliance showcased the RS60 cell, with a timeframe of 9/25 expected back then. Who knows if that's for sampling but hopefully we will see it before the year ends. Looking through their site though I saw quite a few new cells I haven't seen anyone mention. Some crazy numbers mentioned like on the RU25 100c pulse, 150A continuous, 8c charging! Cells that have my attention though are the higher capacity ones like the RS60, RS65, and RP70. The RS60 could be the first 6ah tabless in the wild, and the RS65 could be a direct competitor of the M65A while of course also tabless, and the RP70 while not being rated high will still be interesting to compare to the high capacity cells we have now, will the tabless design help increase peak performance but maybe not cells temps giving its rating?

 

[Pajda]

I have confirmation is in mass production and will be ready to sell by the end of this month. I am waiting for Mooch results.

@ZEUS-FL sent me some 50XG samples yesterday for cycle life testing. I reckon they'll arrive just as the EVE 50PL completes 1000 cycles. I am really looking forward to the 50XG results. I think Tenpower is one of the few manufacturers that has a chance to beat Reliance in this parameter.

 

[ZEUS-FL]

@Pajda
This is just my personal theory about why these two companies show such strong performance similarities. I’m quite sure they have some form of behind-the-scenes collaboration, and there’s a good reason to think so both companies’ chairpersons are siblings.


TenPower’s chairman, Kai Chen, and Reliance’s chairwoman, Maggie Chen, are brother and sister. This could explain a lot of the similarities we’re seeing now and possibly even more in the future. They’re probably sharing technology and R&D efforts between both companies.


领导团队 - Tenpower
公司概况 - Reliance 睿恩新能源

 

[thermal_runaway]

@Pajda
This is just my personal theory about why these two companies show such strong performance similarities. I’m quite sure they have some form of behind-the-scenes collaboration, and there’s a good reason to think so both companies’ chairpersons are siblings.


TenPower’s chairman, Kai Chen, and Reliance’s chairwoman, Maggie Chen, are brother and sister. This could explain a lot of the similarities we’re seeing now and possibly even more in the future. They’re probably sharing technology and R&D efforts between both companies.

TenPower might consider themselves at risk of being a sanction target; EVE was already put on the list. Wouldn't be surprised if this is an attempt to front run any ban. See Ampace being nominally independent of CATL.

 

[andreaskhoi]

Tenpower 50XG datasheet if it hasn't been posted yet.

 

[Elios.pk]

Tenpower 50XG datasheet if it hasn't been posted yet.

Thank you very much.

May I ask where did you get it ?

I tried downloading it from their website but it said that it wasn't available yet (even tho your document says it has been published in august)

 

[Pajda]

You can also download previous V0.1 version of the 50XG datasheet from nkon https://www.nkon.nl/en/amfile/file/download/file/801/product/5883/

 

[BlueSwordM]

It appears tabless 46950s, without shipping, are around 86$USD/kWh.

 

[Antony-DIY]

@ZEUS-FL sent me some 50XG samples yesterday for cycle life testing. I reckon they'll arrive just as the EVE 50PL completes 1000 cycles. I am really looking forward to the 50XG results. I think Tenpower is one of the few manufacturers that has a chance to beat Reliance in this parameter.

Hi guys! Seeing the data base of 50xg and according that molicel with Tenpower will release the M65A 21700 cell, makes Tenpower a trustworthy company!!

 

[BlueSwordM]

Hi guys! Seeing the data base of 50xg and according that molicel with Tenpower will release the M65A 21700 cell, makes Tenpower a S

Same here. Unlike EVE with its nearly 8 month lead before production for the EVE 50PL, I'm tempted to go for the 50XG in my next order and my own final ebike pack build instead of the 50PL.

 

[thermal_runaway]

Hi guys! Seeing the data base of 50xg and according that molicel with Tenpower will release the M65A 21700 cell, makes Tenpower a trustworthy company!!

Tenpower has been around for a while, TTI uses their cells in some models I think. Primarily power tool/micro e-mobility.