Lithium 18650 Safe Chemistry Performance Shootout @ 5, 10, 15 Amps - AW Added

I just did a CBA-II discharge shootout of the safe Lithium chemistries that I have discussed in other threads, such as this one. Thumbnail images, and graphs with detail capacity and how they hold voltage at 5, 10, & 15 Amp discharge rates. The factory capacity specs (as one might expect) are more optimistic than reality shows.

None of these other 6 cells have a protection circuit in them. They were all taken from various battery packs as described in this thread. I just added the nice performing AW IMR-18650 sold in this thread for $9

The cells started at room temp. They did not got warm with 5 Amp test, but all got warm/slightly hot (80-90° F) at 10 Amp discharge test.

At the 15 Amp discharge they got HOT, reaching peak temps listed below (verified by laser thermometer & Fluke 179):

Added Sony V & VT label images. See AW's sales link or post #5 below images.

Re: Lithium 18650 Safe Chemistry Performance Shootout

Let me throw in some test results of my own brand of Li-MN 18650s. These are designed for flashlight use with a featured button top for better cell to cell connection. Discharge graph shown a pair of cells for consistency test from 3A to 15A :

Re: Lithium 18650 Safe Chemistry Performance Shootout

Thanks.

This is very helpful.

Re: Lithium 18650 Safe Chemistry Performance Shootout

AW said:

Let me throw in some test results of my own brand of Li-MN 18650s. These are designed for flashlight use with a featured button top for better cell to cell connection. Discharge graph shown a pair of cells for consistency test from 3A to 15A :

Click to expand...

AW, what is your timeframe on these? Also, can you perhaps narrow the CBA display ranges for graph, as I cannot read your legend. I set my display graph properties to display from 2.00V to 4.200V & from 0 Ah to 1.7 Ah. (Photo size 800 pixels wide)

So it sounds like yours are going to do better than either Emoli or Sony/Sanyo/Konion ? That would be an amazing accomplishment, given their resources !!! I'm not doubting you, just amazed that the "big guys" can be outperformed.

Re: Lithium 18650 Safe Chemistry Performance Shootout

Photobucket is limiting my picture size to 799 x 438 so I can't make it bigger. I would say the performance of these cells are on par with the Konion V cells ( both rated 1600mAH ).

Re: Lithium 18650 Safe Chemistry Performance Shootout

Lux - thank you for this very helpful data. Excellent work.

AW - Wawaweewahhhh, very exciting to see your new bats! Do you have a time frame for availability?

Re: Lithium 18650 Safe Chemistry Performance Shootout

Ahhh that's better...what was confusing me was the 3A being at bottom of legend that I though was referring to 15A set of lines. FYI bottom "X" axis has ranges of 0.2Ah increments

Re: Lithium 18650 Safe Chemistry Performance Shootout

Yeah I was too lazy and I decided to add the 2C tests when I finished the 5A / 10A / 15A tests.

Re: Lithium 18650 Safe Chemistry Performance Shootout

AW said:

Let me throw in some test results of my own brand of Li-MN 18650s. These are designed for flashlight use with a featured button top for better cell to cell connection. Discharge graph shown a pair of cells for consistency test from 3A to 15A :

Click to expand...

Pretty impressive
are you planning to offer those ?

Re: Lithium 18650 Safe Chemistry Performance Shootout

Don't want to hijack this thread so I won't discuss anything that 'll promote my new cells.

Lux, you may want to do a 15A test on those cells and pay special attention on the temperature because they 'll heat up by a margin ( even though all of them have a very low internal resistance ~30mOhm ). There is a reason why the 26500/26700 cells are using paper wrappers.

Re: Lithium 18650 Safe Chemistry Performance Shootout

AW said:

Don't want to hijack this thread so I won't discuss anything that 'll promote my new cells.

Click to expand...

you're right...

Re: Lithium 18650 Safe Chemistry Performance Shootout

AW said:

Don't want to hijack this thread so I won't discuss anything that 'll promote my new cells.

Lux, you may want to do a 15A test on those cells and pay special attention on the temperature because they 'll heat up by a margin ( even though all of them have a very low internal resistance ~30mOhm ). There is a reason why the 26500/26700 cells are using paper wrappers.

Click to expand...

AW, I started this thread to keep educating people on these safe chemistry cells, and if you have them coming for sale, please give details here as desired so it is all in one place. Otherwise people have to harvest these from various tool packs.

As a general guideline, most of the tool pack sources are averaging about $8-10/cell from Ebay sales (only get new packs & after EBay seller reputatin is verified by ratings), although there is a 20 cell Bosch 36V pack that used to be selling for $73 with free shipping from Amazon...which now almost doubled in price. Glad I got some last week. Then there is the need for a security hex wrench to remove screws, and careful pulling apart cells without shorting or damaging anything, and the time cleaning them up. oo:

Thanks for heads up on the heat. I wish the CBA-II also stored temp profiles for graph since it displays it live. For the first round of these tests, I just charged them all in a Pila IBC charger until green light. Except charged two A123 in series with Hyperion 1210i using that A123 profile.

Re: Lithium 18650 Safe Chemistry Performance Shootout

I'm trying to understand the excitement about these cells from a practical point of view.

From a brief back of the envelope calculation I estimate that one of the high drain subC NiMH cells has about the same volume as an 18650 and has about the same energy storage in watt-hours (perhaps a little less than the best LiMn cells, but not much).

On the positives for subC they have an even higher current capability, and three in series have a lower internal resistance than one LiMN cell. They have a more convenient form factor for mounting in a flashlight tube and a series pack is more convenient to charge with no need for balancing taps. By and large they are cheaper and more readily available, even considering the higher quantity needed to make up a pack.

On the positives for the lithium chemistry are the higher voltage, meaning fewer cells are needed to provide the voltage for big incans.

What am I missing? Where do the safe lithium cells win over NiMH?

Re: Lithium 18650 Safe Chemistry Performance Shootout

Mr Happy said:

...What am I missing? Where do the safe lithium cells win over NiMH?

Click to expand...

Well, several things...but I don't discount your questions about them. Nothing is perfect for all purposes.
Having said those points, there are also real limitations, such as:

Re: Lithium 18650 Safe Chemistry Performance Shootout

AW said:

Don't want to hijack this thread so I won't discuss anything that 'll promote my new cells.

Lux, you may want to do a 15A test on those cells and pay special attention on the temperature because they 'll heat up by a margin ( even though all of them have a very low internal resistance ~30mOhm ). There is a reason why the 26500/26700 cells are using paper wrappers.

Click to expand...

Forgive the dumb question but Whats the reason for the paper?/ obviously something to do with temperature...

But alot of people pull of the card, and re wrap with capton tape...including myself for some mods, should that not be done?




Questions aside :


Great Thread Lux!!!

And Good Effort On the Cells AW.

Re: Lithium 18650 Safe Chemistry Performance Shootout

Raoul_Duke said:

Forgive the dumb question but Whats the reason for the paper?/ obviously something to do with temperature...

Click to expand...

I suppose because paper is more heat resistant than thermoplastic film?

Re: Lithium 18650 Safe Chemistry Performance Shootout

The bigger cells in power tool packs may heat up to 70-80 degree C under pulse loading of 40+ Amps. Regular shrink wrap will shrink more at this temperature posing a risk of exposed metal casing and a short. Cardboard will sustain higher temperature without any issue.

Re: Lithium 18650 Safe Chemistry Performance Shootout

Thank You Lux and AW for posting these results....

I was initially concerned that the alternative lithium-manganese cells popping up in packs, (like the newer Ryobi you tore open) might be of lesser quality, but after looking at your charts, for practical purposes, there appears to be very little difference to be concerned about.

Eric

Re: Lithium 18650 Safe Chemistry Performance Shootout

I have added this thread to the "Threads of Interest" at the head of this section so we can keep track of it.

Tom

Re: Lithium 18650 Safe Chemistry Performance Shootout

Thanks Tom! For reference, I bought the Bosch 36V pack with 20 x Sony cells, and these present yet another version of Lithium Manganese cell from the ones I listed in first post. This is green model SF-US18650-VT which looks almost identical from initial shown US18650-V model.

However these two Sony models apparently have different mAh capacities from each other, and different discharge performance rates. Initial reports (& from Sony's website) claims the "VT" model has 1100mAh, whereas "V" model is 1500mAh.

I will test these Bosch pack "VT" models at 5 & 10 Amps and add to above performance curves. I also plan to do 15A discharge rates on all these cells.