Hohm Tech HohmGrown 32.3A 4307mAh 26650 Bench Test Results...only 23A, same as Basen/Brillipower

[Mooch]

These cells were donated for the purposes of testing by All Day Vapes (www.alldayvapes365.com). Thank you! To prevent any confusion with the eGo-type "batteries", I use the term "cell" here to refer to a single 18350, 18650, 26650, etc.

While the test results are hard data, the conclusions and recommendations I make based on these tests are only my personal opinion based on my criteria for setting a rating. Carefully research any cell you are considering using before purchasing.

Testing cells at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved and how to minimize them.

If the cell has only one current rating number on it, or if it says "max discharging current" then I have to assume that the company is stating that the cell can be discharged at that current level in any way, including continuously.




Bottom Line
This is only a 23A cell that I am rating at 4300mAh. It is identical in appearance and performance to the Basen and Brillipower 4500mAh cells. It is damaged after just a single discharge at its 32.3A rating and the voltage at that discharge current level is very low. The Grown cell only delivers 181mAh down to 3.2V at its rated 32.3A.

Having said this, it is still one of the better performing 26650's as it seems to use the same cell as the Basen and Brillipower 4500mAh cells. The 26650 ratings/performance table has been updated to include the Grown cell.

This testing has been part of a weeks-long series of events that have also involved Hohm Tech. I want to say that Hohm Tech strongly believes that their testing methods and ratings are valid and accurate and they stand firmly by them. They insist that the HohmGrown cell is an improvement over the cell that is used by Basen and Brillipower. I am unable to explain why I do not see that difference in my testing.


Continuous-Current Test Results (with comparison to Basen/Brillipower at 15A)



Pulsed-Current Test Results



Comments

• At 0.5A continuous it reached 4299mAh. I am rating this cell at 4300mAh.
• At 10A continuous the temperature rose to 48°C. This is significantly below the average temperature of a cell running at its continuous discharge rating (CDR).
• At 15A continuous the temperature rose to 63°C. This is below the average temperature of a cell running at its continuous discharge rating (CDR). Discharges of the Basen and Brillipower 4500mAh cells were also included for comparison to the HohmGrown cell.
• At 20A continuous the temperature rose to 74°C. This is just a bit below the average temperature of a cell running at its CDR and is an indication that we are near the cell's true rating.
• At 25A continuous the temperature rose to 87°C. This is above the average temperature of a cell running at its CDR and is an indication that we are over the cell's true rating.
• At 30A continuous the temperature rose to 96°C. This is an incredibly high temperature and a clear indication that we are above the cell's true rating. The voltage is sagging very badly, another indication thst we are above its rating.
• At 32.3A continuous, the cell's rating, the temperature rose to 98°C and the voltage is sagging very badly. Additional discharges show damage being done to the cell every time it is discharged at this level. The cell only delivered 181mAh at 32.3A down to 3.2V. It is clearly not a 32.3A cell.
• I am setting a CDR of 23A for this cell. Operating at that level would bring the temperature near to the average for a cell operating at its CDR. While operating any cell near its rated maximum current level causes damage to the cell, I would expect decent cycle life from this cell at 23A continuous.
• I have included pulsed discharges but I haven't set pass/fail standards for pulse testing yet. The discharges were done at 5sec on/30sec off, down to 2.5V. One chart shows the entire discharge at each level. The other chart is zoomed in to show the first 5 minutes to make it easier to see the voltage sag at different current levels.

To see how other cells have tested and how hard you can safely push them, check out these links:
List of Battery Tests | E-Cigarette Forum
18350/18500 Safety Grades and Pulse Performance Data | E-Cigarette Forum
18650 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum

 

[BrandonDigital]

Hi I seen on Reddit that Hohm Tech responded to this test (copy/paste):

" Hello Reddit members. We are thrilled with this posting, although it doesn't highlight us favorably, we are excited to see users here discussing the topic. Various testing methods will all ultimately lead to different results. However, no one at Hohm Tech Corp., BBC, or IC would devalue or question the results and great work John "Mooch" puts forth. These are the results he has found and we agree it does not look favorable. We greatly appreciate his sincere dedication to the industry and the direction of that dedication. Hohm Grown cells were tested by a 3rd party of IC (Indonesia Chemistry) and again internally at BBC (Bofuneng Battery Co.), in which they set and grade the valuations in which we concur with by the results we achieved in-house from an analog testing apparatus that runs cells wide open. BBC stock cells are rated at 26A & 29A CDR, in which they build for power tool manufacturer battery packs. However, their testing method and protocol of methods are surely different and lead them to different valuations/grading. This we cannot elaborate on as we are not in position or aware of these methods of tests. All in all, if we, or the Hohm Grown cells are referred to as bogus, "snake oil", etc, we can only humbly wish users the best of experience with any 26650 cell they may wish to go with. We won't partake in further testing of the cells as they've proven to be among best available with our EPTC applied to it, cathode revision, and 1.9% chem modification. Although the results aren't a "revolution", we are pleased with the results towards safety and the headway towards further evolution of li-ion cells. "

Hohm Tech HohmGrown 32.3A 4307mAh 26650 Bench Test Results...a 23A battery, identical to Basen/Brillipower 4500mAh • /r/electronic_cigarette

I have read and watched many cell results, and have seen companies fight back versus addressing the issues/concerns. This reply by Hohm Tech was sensible, and quite respectful and has my faith continuing on with them. I can't vouch for Basen, but I can with Brillipower, AWT, and MXJO. IMO, these Growns have performed very well for me. I haven't pushed the Grown cell terribly hard, as I build primarily a .08-.12 ohm setup every time (unregulated). I can however say that without a doubt the Grown cell is hotter than my yellow AWT's, MXJO's, and Brillipower. I admit the Brillipower is darn close, but I do sense faster heat formation and overall hotter vape. As always Mooch is the man