I remember comparing cells on Batemo and being surprised by the difference between power and current between cells meaning Molicels sagged less.
You are right it won’t change the rankings but it might change whether a different brand is worth it over molicels. If I get some from Nkon I can let you know.
edit: actually it looks like cells like tenpower 40tg are all round better than eve 40p.
Links?
The big thing to remember IMO is the limited voltage range for these discharges. At moderate to high power levels a great cell is going from about 3.6V or lower (after initial sag) down to 3.0V. There’s not much of a change in current for a constant-power (CP) discharge over that limited a voltage range.
For example:
120W CP = 33.3A to 40A for that voltage range.
37A CC discharge is never off by more than about 10% for that current range and very close to it for most of the discharge. A cell that sags a bit more means even less of a change in current.
Same +/-10% worst case or so for a 100W discharge.
Nothing against CP discharges at all though. CC easier for many though and just pointing out the numbers and why I stick with CC for my testing most of the time.
Batemo data for 40P https://www.batemo.com/products/batemo-cell-explorer/eve-energy-inr21700-40p/
Batemo data for 40TG
And it’s €2.65 per cell when buying 130 which is perfect.
Thanks!
Essentially identical IMO, no noticeable difference in use. Would need cycle life testing at moderately abusive levels to know for sure how they compare.
It might be down to cost for me. Looks like 40P is a touch more expensive?
Arrgghh….US vendors just don’t have all these great cells!
I’m not sure about the hazards of shipping them but i could send you cells.
Are,you in the EU?
I’d be happy to pay for the cells and take the time to test the 40P and 40TG if you sent them to me here in NYC! Discharging them down to 2.8V removes most of their energy and triple packaging them with lots of air space (assuming the box will be crushed is a good thing to do) prevents them from getting damaged.
I can’t afford to pay for the cells, take the days to test them, and also pay for shipping though. Shipping from the EU costs a fortune! But DHL is the best option IMO, I just received cells from a client in France via them.
Yep I’m in Ireland stuff from Nkon takes just 4 days. DHL is really expensive €80-90 but An Post here will do it for about €15 which I don’t mind covering.
I saw the 40P when they were available but they are out of stock again I’ll contact you as soon as they are available. If it takes long I’ll get a Tenpower cell in the meantime.
I need two cells for any you can send, happy to pay for them.
Yes, he told me that expected Molicel INR18650-P30B and INR-21700-P50B after about 10 weeks. It was 5 of may (3 weeks ago). So, finally we know the price and time. It is good news!
for my project with 56 cells (14S4P) it will be not so cheap =( Samsung 50S cost 3.55€ per pcs. P50B - 9.95€. Alsost 3 times more expensive =( Also customs tax…
This is great to hear!
These will probably be the same “engineering samples” I have and not production cells so there might only be a few available. If anyone wants to buy these I recommend you get them immediately after they go live. They will sell out,quickly and it could be many moths before more are available (same as P28A, P30B, P42A, and P45B).
If someone needs a few cells for testing, I can bring these from EU to US in hand luggage.
Will also ask Moli if the NKON offer for P50B are from their test production run in Taiwan.
Was told “P50B will be sometime in Q4, likely closer to the end of Q4.”
In 2025 a company I know will order palets of P45B and P50B direct from the factory.
So I can offer these cells in EU.
In the last years theres been a huge jump in commercially available cell’s ability to store energy and power. How is molicell doing it? Aren’t these high energy/power cells inherently less safe as insulation is getting thinner? Break through dendrites more likely? Spontaneously internally shorting more likely? Instant fire more likely?
Maybe wait for mass production in Q4.
The separator doesn’t have to be made thinner but it could help with allowing thickening of the current collectors to reduce IR. But if they kept it the same then the triple tabs to the bottom inside of the can (and the top contact?) they use could account for the low IR since the tabs are a real choke point for current.
Over the years the separators have gotten thinner but dendrite growth, and cell failure from that, isn’t much of a problem. The cells are retired at the manufacturer’s end-of-life, well before reasonable used cells start to get too much dendrite growth.
It’s the overcharged, overdischarged, charged when cold, etc. , cells…ones that have been abused…that are the ones that could potentially have risky dendrite growth. You just don’t get that kind of risk increase in cells that are used within their specs.
These newer cells, from any manufacturer, do probably have a higher cobalt content***, up from 50% and 60% for older cells to 80% or even 90% for ultra-high energy cells. That gives them more power for the weight/volume but brings them closer to LiPo’s in terms of volatility (since LiPo’s use a 100% cobalt cathode, lithium-cobalt-oxide, LCO).
So they don’t need thinner separators or thicker current collector foil to be riskier to use but those higher cobalt (higher power) cathodes mean their thermal runaway threshold temperature is probably lower and their reactions in runaway will be more violent. Not as bad a LiPO but most people won’t make that kind of distinction when their pack is acting like a pile of rocket engines.
Does this make these newer cells “more dangerous”? That’s a judgement call for each of us. I guess if someone considers LiPo’s to be a lot more dangerous then newer standard li-ion cells (with higher cobalt cathodes, that is) could be considered “less safe” than older lower performance cells with less cobalt in them.
With li-ion there is always a tradeoff. 
***Going from NMC532 and NMC622 chemistry up to NMC811 and NMC955.
That’s what I was told too. I’m guessing Q1 2025 before we can actually have a chance to buy production cells.
My other guess is that Nkon found some of the “engineering sample” cells, same as the ones I tested. This is what happened with vendors and P42A’s and P45B’s.
Occasional small lots of sample cells becoming available for the year or two it took before the cells were in production and more available.
Not P50B but P45B
What would you estimate the cost for 12pcs of P50B shipped to Oregon? And what would you estimate for timeline?
The 40TG is back in stock and 40P is available for pre-order. I’m about to order them do you want anything else from Nkon.
