Molicel P50B variable charge-rate cycle life test

[BatteryMooch]

Small update:

- added more cycles
- after 1700 cycles at 15 min charging still well above 70% SOH

Thank you for the update!
Fantastic cycle life.

 

[gruiz]

Hey Pajda, Awesome data! Do you happen to have data on the typical variation in initial capacity for your cells (and how many were tested)? I'm designing a BMS for these and my design will change based on how much my cells differ in capacity.

 

[Pajda]

The short answer is no. The main reason is the amount of time such test consumes. In any case, this is a very good point and I am aware that it would be desirable also to perform cycle life tests on at least two samples. But again for me this runs into data processing time problem and also don't have an infinite number of channels on my battery test system.

However, cell consistency tests have recently started to be conducted by @BatteryMooch and I think the P50B will be coming very soon.

 

[Pajda]

Small update:

- added more cycles
- 4C @ 15min charge-rate sample reached 2000 cycles, where you can see it has had enough.

 

[gruiz]

Okay thanks for letting me know. Also, I looked into it more, and found that typically a BMS doesn't really do balancing in order to account for inherent cell capacity differences, and mainly just does it to maintain a consistent SoC. I'll just capacity test my cells before assembling and try to match them as well as I can.

 

[Dan93]

I think it'd be awesome to see the 3C and 4C tests continued until complete failure (1C and 2C would probably take too long I imagine). Molicel's cells are some of the hardiest out there, so it would be interesting to see where their true limits are in terms of cycle-life.

 

[Pajda]

At the beginning of this P50B test, I doubted that it would last 1000 fast charging cycles at 3C charge-rate. So I had the same thought and let the test continue for 2000 cycles. However, the main reason why I decided to stop at 2000 cycles is that two new cells EVE 50PL and Reliance RS50 (it is only with me for a week) have come up in the interim. And once again, unexpectedly for me, both cells absolutely crushes the P50B in all aspects (even the 1 year calendar life test for the P50B didn't go well). And since I have few 20A channels on my battery test system, I decided to free them up for the RS50 and 50PL.

 

[freesty]

At the beginning of this P50B test, I doubted that it would last 1000 fast charging cycles at 3C charge-rate. So I had the same thought and let the test continue for 2000 cycles. However, the main reason why I decided to stop at 2000 cycles is that two new cells EVE 50PL and Reliance RS50 (it is only with me for a week) have come up in the interim. And once again, unexpectedly for me, both cells absolutely crushes the P50B in all aspects (even the 1 year calendar life test for the P50B didn't go well). And since I have few 20A channels on my battery test system, I decided to free them up for the RS50 and 50PL.

totally understandable. Both are better price performance value then the P50B.

 

[Pajda]

Small update:

- added more cycles
- added two new charts in 2000 cycle test: Remaining test @ IEC test capacity

 

[Pajda]

Small update:

- added more cycles
- 1C @ 60min charge-rate sample reached 2000 cycles

 

[evolveinla]

Hey, this is Patrick - CoolWatts on YouTube. Just wanted to say thanks for the great work and incredible amount of time you've put into this. This testing and your results provide super valuable information for PEV, e-moto, eskate, and vape enthusiasts everywhere.

 

[Pajda]

Small update:

- added more cycles
- all samples now reached 2000 cycles which is the end of this particular test

Pajda`s remarks and comments:

- The first sample began testing on July 23, 2024, and the last sample completed 2,000 cycles on October 6, 2025.
- When I started this test, I had no idea that the Molicel P50B would be so quickly outclassed in every respect.
- On my Patreon channel, you can already find comparison results for EVE 50PL, Reliance RS50, and Ampace JP30 at the 2C@30min charge rate and recently I started even 3C@20min test with RS50 (The EVE 50PL does not have 3C continuous charging allowed in datasheet, but that will not stop me from performing this test anyway in the future)
- I am now eagerly awaiting the arrival of the Tenpower 50XG sample, which could rival the current market leader, the Reliance RS50, whose parameters have already been confirmed by @BatteryMooch and @ZEUS-FL

 

[Gika]

Piccolo aggiornamento:

- aggiunti più cicli
- tutti i campioni hanno ora raggiunto 2000 cicli, che è la fine di questo particolare test

Osservazioni e commenti di Pajda:

- Il primo campione ha iniziato i test il 23 luglio 2024 e l'ultimo campione ha completato 2.000 cicli il 6 ottobre 2025.
- Quando ho iniziato questo test, non avevo idea che il Molicel P50B sarebbe stato surclassato così rapidamente sotto ogni aspetto.
- Sul mio canale Patreon, puoi già trovare i risultati del confronto per EVE 50PL, Reliance RS50 e Ampace JP30 con una velocità di carica di 2C a 30 minuti e di recente ho iniziato anche il test di 3C a 20 minuti con RS50 (l'EVE 50PL non ha una carica continua di 3C consentita nella scheda tecnica, ma ciò non mi impedirà comunque di eseguire questo test in futuro)
- Ora attendo con ansia l'arrivo del campione Tenpower 50XG, che potrebbe rivaleggiare con l'attuale leader di mercato, il Reliance RS50, i cui parametri sono già stati confermati da @BatteryMooch e @ZEUS-FL

Ciao, devo montare un pacco batteria da 20 s per la mia e-bike con celle ad alta scarica... dopo tutti i test effettuati, quali celle pensi siano le tre migliori sul mercato?