Molicel P50B - 60A 5000mAh 21700

[Asphalt]

A high-performance cell that enables the possibility of 1p packs.

Opens up the potential for ultra-lightweight EUCs.

 

[on one]

That's amazing, where can I buy some of these?

[alcatraz]

Test results.

This preproduction model seems to struggle past 30A discharge rates when left uncooled.

I forgot if the 50S could do 20 or 25A continuously "uncooled".

Edit: Indeed the 50S overheats at 25A continuously. It's essentially a 20A cell without cooling.

It means that the P50B can sustain ~50% more current than Samsung 50S. That's a good start. What of pricing?

Edited July 31 by alcatraz

[Asphalt]

Here are the more detailed test results by Mooch:
https://www.e-cigarette-forum.com/threads/bench-test-results-molicel-p50b-60a-5000mah-21700.986092

Looks like they are available on AliExpress, but I have no idea if they are legit:
https://www.aliexpress.com/item/1005007198071228.html

Molicel has a manufacturing facility in Vancouver, Canada, but I don't know if they do direct sales:
https://www.molicel.com/tag/p50b/

Molicel P50B vs Samsung 50S

Capacity:

• Both 5000 mAh

Discharge:

• Samsung 50S = 35A
• Molicel P50B = 50A

Weight:

• Samsung 50S = 72g
• Molicel P50B = 68g

Price:

• Samsung 50S = €4.99
• Molicel P50B = €12.45

Comparison source:
https://eu.nkon.nl/molicel-inr21700-p50b-5000mah-50a.html
https://eu.nkon.nl/samsung-inr21700-50s-5000mah-35a.html

[Asphalt]

The battery pack currently used in the mTen4, mTen5, A2, and A2+ are all 20s2p, available with both Samsung 50GB and 50S.

The Samsung 50GB is rated for 10A discharge (https://eu.nkon.nl/samsung-inr21700-50gb.html)
So a 20s2p pack would be rated for 20A discharge.

A 20s1p Molicel P50B pack would be rated for 50A max discharge.
Even at an uncooled 30A discharge (thanks @alcatraz for pointing this out), the 1P Molicel P50B (30A), still outperforms the discharge of 2P Samsung 50GB (20A).

The weight of a 2P Samsung 50GB pack is 2S * 20P * 70g = 2800g (6.16 lbs)
The weight of a 1P Molicel P50B pack is 1S * 20P * 68g = 1360g (2.99 lbs)

I'm excited by the possibilities of the new form factors and use cases that this cell enables, especially when combined with lightweight materials and thoughtful design.

[thendless]

What caught my eye in the review was the following:

"After 300 abusive cycles (30A discharge to 2.5V, recharge at 5A while still warm) the P50B only lost about 11.5% of its run time and had essentially the same max temperature and DC internal resistance as when new. This is incredible."

[alcatraz]

The cooling aspect can vary. In a lab environment there's room temp 20-25C so a limit of 80C for the cell gives us a delta of 60C. (80-20)

When riding you might have a smaller delta if any part of the pack heats up (proximity to controller, legs, riding after fast charging, hot ambient temp, long descents). So you might wish to have some headroom.

However riding rarely requires continuous max amps so the cells will have time to cool. You can exceed 30A for short bursts without problems.

It's good to assign a discharge rate so you can compare cells. Traditionally a 10A cell does 10A sustained. Now with P50B and 50S we're beginning to see specified rates that can't be sustained. It's a bit deceiving so to be fair it's best to look at a 50S as 20A and P50B as 30A when comparing, regardless of the specified rates.

The infamous M50T were claimed to be 10A cells but in testing did 7A without overheating. That should have been a warning.

Edited August 1 by alcatraz

[DavidB]

18 hours ago, Asphalt said:

I'm excited by the possibilities of the new form factors and use cases that this cell enables, especially when combined with lightweight materials and thoughtful design.

At 2.5 times the price of 50s cells I am less excited. Even more so on 1P battery packs. May be ok for a scooter but not an EUC.

[alcatraz]

6 hours ago, DavidB said:

At 2.5 times the price of 50s cells I am less excited. Even more so on 1P battery packs. May be ok for a scooter but not an EUC.

These cells are only superior in small packs so the price might not be a dealbreaker. Personally I'd still go with 50S. What's the hurry? 

[Asphalt]

7 hours ago, DavidB said:

At 2.5 times the price of 50s cells I am less excited. Even more so on 1P battery packs. May be ok for a scooter but not an EUC.

The Molicel P50B is a brand-new cell, so prices are at a premium with limited supply.
Prices will drop as availability improves.

While 1P EUC battery packs are now feasible, it also means significant performance possibilities in 2P packs - we might actually see an A3 or a Falcon 2 that can hit 35 mph.

[mhpr262]

The guys in all the high performance flashlight forums on the internet must be getting a rock-hard erection right now

[xiiijojjo]

This is really exciting for battery technology, but I doubt we'll see them in EUC anytime soon. I have a feeling that 50S is here to stay for the foreseeable future, but I hope I'm wrong.

[Tep]

The key point is that this cell is too expensive. The only reason we're seeing Samsung 50S getting used in EUC production is because there was a notable price drop for bulk pricing last year.

I can see people getting their packs custom made with this cell, but that's about it, for the average Joe, 50S should be fine for most use cases.

[alcatraz]

6000mAh cells are incoming and they aren't expensive. So the choice is going to once again be range/lightweight vs power (50S). 

[mhpr262]

12 hours ago, alcatraz said:

6000mAh cells are incoming and they aren't expensive

That's great to hear. Those would be perfect for me as I almost never go faster than 20mph and barely put any load on the battery. I love the range of my EX20HT with the 3.6kWh battery, but damn is it heavy. A 6.000mAh cell might get us a battery pack that has the same range but is a good deal lighter.