Useful Li-Ion battery site

I thought it was a great attempt at humor as I never could stand it when my fakkus got damp. If I got it, I’m sure SabbelMR did. BTW, what exactly is a ‘fakkus?’

Keith

Well, I did actually understand that it was a great attempt at humor, but as a non-native speaker all I understood was something about moisture and … well probably we should draw a line here :)…

Hehe, there is no such word…

It’s Dampf Akkus, where Dampf = Vape and Akkus = rechargeable batteries (in German we’ve got Batterie = primary battery and Akku = rechargeable battery, as in “accumulator”…).

Excellent work there on the site. Thanks for the effort and input here.

dumb fuckas ? original website :d

Pardon?

:slight_smile:

Good example for the reason why humor works best on an international level if it's funny without words (like Mr. Bean).

Obviously, the German word "dampfakkus" (which is plural of "dampfakku") can be misread as damp fakkus.

So, just like ChiX doesnt like when his fakkus gets damp, scheven took it to a whole new level, making it "dumb fukkas". :D

I'm curious about how the Efest cells will perform.

Btw. are those SMR cells still available? And which cells are inside? Seem to be better than AWs.

Yeah.

And … that would be, eh, let’s try to re-wrap it politely, something about moisture and people you dislike :)?

Oh my god we should have chosen a different domain name in the first place :).

But I am glad that we could contribute some entertainment, too ;). As I said, a more international domain name that will redirect to an english version of the same site is on its way.

What I can tell you is that EFest IMR 14650, 18500 (flat top) and 18650-1500 are the well-known “BDL” aka “BIO” IMR, technically unchanged (proven by measurements, not all of them posted yet though) but now with EFest branding.

As for EFest IMR 18350, 14500 and 16340, these are different from the former BDL/BIO types. Optically, aside from the EFest branding, the positive pole has changed.

The EFest IMR 18350 “flat top” (raised flat top actually) outperforms the BDL/BIO IMR 18350 and can now be stacked, is however still not as good as the AW IMR 18350:

http://www.dampfakkus.de/akkutest.php?id=49

However, EFest is coming up with button top versions of some of their sizes, and the EFest IMR 18350 “button top”, on the other hand, performs worse than the EFest IMR 18350 “flat top”:

http://www.dampfakkus.de/akkuvergleich.php?akku1=49&akku2=47&akku3=146&a=2

The rather new EFest IMR 18650-2000 however performed reasonably well. We will be able to show graphs soon.

The SMR IMR outperformed the AW IMR in 14500 for instance - yes.

But no, they are not publically available and probably never will be. They were made according to my own spec for me by a battery factory as a “proof of concept” that good value for money is possible (IMR 14500 was 2.30 EUR, IMR 18350 2.50 EUR, IMR 18500 3.40 EUR and IMR 18650 3.70 EUR) for a group order at our German vaping forum.

I found that the Efest IMR 2000mAh had a rather high internal resistance and got very hot at high currents. I suggested an alternative cell to use before they get into the full swing of production.

Hi torchy,

what current did you test the EFest IMR 18650 2000 at?

Probably we are talking of a different battery, as mine was a pre-production sample. Perhaps I can send one of my samples to you for comparison.

I will e-mail you later :)…

i want to drive a 120w 12v DC motor How should I choose a combination of reasonable battery life, I need to bring the battery as much as possible the quality of small so it is necessary and reasonable arrangements for the battery and the capacity of each block in about 10-20 minutes.

Go for a serial / parallel combination of a modern high-current ~2.2Ah 18650 cell like for instance Panasonic CGR18650CH, Samsung 18650-22P or Sony US18650V3 (all three LiNiCoMn chemistry and capable up to 10A / cell, so you just need approximately half the number of cells as opposed to classic LiCoO2 / ICR chemistry cells to deliver the same amperage).

There also are some good LiNiCoMn 26650 cells like Kingpower (Kingkong) INR 26650 or Microvast 26650 LiNiCoMn cells - you may want to check if a combination of these gives you more energy density or cost effectiveness for your particular setup.

Oh and you will need balancing and some sort of PCB, of course.

But I guess this is somewhat off-topic here. There is e-mobility forums out there (e-bikers) where people are more into battery pack building.

And there is a lot of companies that would customly design battery packs according to your spec, maybe you want to look out for such a vendor for professional consultation.

120W12V DC motor rated current is about 10A, the battery energy storage for 20 minutes work a maximum power of 120W 40Wh capacity of the battery pack needs about 12V4Ah with lithium-ion batteries power batteries.
Recommended by the combination of manganese lithium-polymer battery

Thanks SabbeIMR! really useful information.

18650 Rechargeable Lithium LiFePO4 Battery .can it even replace two AA cells (on some devices that could use 3.6~3.2 instead of 2.6~3v)?

It can, yes. You could use a 14500 rechargeable LiFePO4 battery and a 14500 / AA dummy spacer cell in a device designed for two AA cells in series, for instance. Be careful though, as your device can be damaged by the slight overvoltage.

For instance, NiZn rechargeable batteries, primarily by the company Powergenix became popular among photographers and other users a while ago as these have some advantages about classic NiMh / NiCd rechargeable batteries, primarily their higher voltage of about 1.7V.

However, what the photographers for instance found is that some 2*AA flash units would work perfectly in a 2x NiZn combination, e.g. with ~0.4V overvoltage compared to 2*AA primary batteries, while a few units got damaged by the overvoltage!

Also, as LiFePo4 is ultra-high drain but low energy density, you may want to check if there is really an advantage in energy density or cost effectiveness to be gained by replacing two AA cells with one LiFePO4 cell (aside from the risk to damage some voltage-sensitive devices).

ASUCELL Rechargeable Protected 3.7V 3000mAh Lithium 18650 Batteries
the quality was brilliant - the best 18650 batteries I had tried.
buy some you will not regret

If you want to see a graph, send us one for review :). As easy as that. We will send it back via registered mail after the tests.

Please understand that we cannot buy all cells on the market, as dampfakkus.de is a private project and 99% of the reviewed cells we bought personally, we did not get them as free samples from vendors or something like that. So it also was a very expensive private project, and we just have to stay realistic, i.e. concentrate on the batteries we consider worth testing.

However, we are always glad for input, recommendations and cells sent in for review (as long as those are just slightly used, as we need representative testing results of course).

They were pretty good when first launched. I bought some of the first production run a couple of years ago, they were around 2600mAh. The last time I tried them they were around 2350mAh.

@SabbeIMR:
When testing the Efest cells do you charge the new cells once and then do the discharge test or do you charge and discharge them a couple of times before testing?
Afaik IMRs need a couple of cycles before they perform their maximum capacity.

From my experience it is rather cells that have been stored for a longer period since manufacturing date that would profit a lot from a couple of “initial cycles”, but generally spoken and as far as your question is concerned:

Yes, usually we have done multiple cycles for each tested cell before a final result finds its way into the database.

To put it kindly, my experience has been the opposite of yours.