Oh boy… I had a feeling this was going to end up being the case.
I guess I’ll have to wait & see. They should be here in a day or two anyhow.
This may be a captain obvious comment, but, is it possible Molicel could be getting different guage insulators & shrink wrap from time to time, run to run?
Ok, well, I received the cells.
I can confirm, all 4 of them look just like @1stein 's pictures with a very slight protrusion.
If it’s useful for comparison, my date codes are-
109 2N120 03
Thanks for the helpful posts folks.
Perhaps. Differences from wrap thicknesses would be minimal but the top ring thickness might vary some.
Length changes between batches (or even within a batch) could also be due to different assembly lines being used, different batches or sources of metal top contact structures, different top contact sealing ring batches, metal can mold wear, and other can assembly stuff like that.
Hi all, recently bought some P45B cells from Illumn. Also got in a Vapcell S4 plus V3 charger from Wurkkos. I’m getting a little low results on the Capacity test and am wondering if this is valid for a new cell literally first discharge and charge. It seems a little low? Charger was left in auto mode. Should it be closer to 4500mAh?
Don’t know if it belongs here or in a Vapcell charger thread
New li-ion cells from the larger manufacturers don’t need “breaking in” unless they’ve been sitting around for a crazy long time. Yes, your results should be above the 4300mAh min spec, up near the 4500mAh typical spec. Those readings you got are very low.
Are your discharges from 4.2V down to 2.5V? I measured 4375mAh and 4401mAh for the two 2022-dated P45B’s I tested.
Yes, since they are new cells I wanted to test the capacity. I believe each started at 3.7V. The Vapcell charger charged it up to 4.2V and discharged down to 2.5V and charged back up to 4.2V for the whole test, as you can see it took around 8hour 30 minutes for each. Does the charging/discharging rate matter here, or something I don’t understand? I left that function on Auto instead of choosing a manual current.
In my experience pretty much anything under 1A for a power cell like the P45B gives you about the same results. The standard is 0.2C though, 900mA for the P45B. Doing it at 1A would be very close.
If you get the same results at a 1A manual setting then I’m thinking it’s just not very good at measuring capacity. If it’s consistent though then you can use it to track capacity loss over time or to compare different cells.
Try cycling the cell three times and see if the capacity measurement goes up. I don’t think it will make a difference…it shouldn’t that is…but it’s worth a try.
If there’s a thread for this model charger here it’s probably worth posting there to see if others have had low readings.
I have a few cells that have been sitting in storage for 1-2 years (80°F, at 3.7V)
Would you recommend “breaking” these in, and if so, how?
I should have phrased that differently, without using “breaking in”.
There can be something called “recoverable capacity loss” but it’s not much (compared to the “irrecoverable capacity loss” that happens over time, in storage or while being used) and I’ve never seen much more than a few mAh recovered.
Even some P42A’s I had in storage since 2019, and were made in 2018, only recovered about 45mAh earlier this year
There’s no way to recover/reverse any noticeable internal resistance increase that I’ve seen but perhaps that is cell dependent. I haven’t read enough about this to know for sure though.
I just use the cells normally and any recoverable capacity comes back that way. Doing a separate cycle, or cycles, just shortens the overall life of the cell with no real benefit here IMO.
Confirm that your cells are still at over 2.5V before using them though. If not, recycle and replace them as they will have been at a too-low voltage for a while and that can cause damage.
On a side note…I’ve seen some pouch LiPo’s that, IMO, seem to have skipped (to save money?) some of the formation cycling that is done after being assembled. These cells can benefit from cycling to improve their performance but you can just use them normally (gently to moderately) for a few cycles instead of wasting the limited number of cycles they have.
Ok, I was able to do the capacity test on my last fresh cell at 1000mA on the manual settings, it took nearly 17.5 hours but we got it done
Does the result look any better @Mooch? Ended with 4276mAh (the last picture) It still seems kinda low compared to what you said, 4375 and 4401
Should I try the next capacity test at 500mA since I can’t go inbetween to the 900mA recommended?
I don’t think it will make any difference but you could try. Unfortunately I think it’s just that your charger isn’t accurate. This is a verrrrry common problem with slot round cell chargers.
