King Kong 26650 is HARDCORE! 4525mAh and it's first cycle only!

I think there is a misunderstanding here, only the palight ones are supposed to be protected.

They may be protected, but you can't see the protection circuit clearly.

It's not protected, through a DMM it does not cut. I made sure i just tapped it and let go immediate. Protected cells cut very fast, minimal sparks also.

I mean the Palight ones.

Sorry guys, I didn't even see the reference to Palight ones. My bad for skimming through the thread.

http://www.intl-outdoor.com/kingkong-26650-4000mah-liion-battery-p-136.html

Sorry to annoy you a little bit 2100.

I would like to know how to do the discharge test for my protected pana NCR18650A from NTL-Int, a friend will do it for me as I do not have an RC charger.

Would you let me know what parameters are to be placed on the charger to do it?

Your friend would be able to cycle through the options and see the discharger option. Just select maybe 1 to 3 amps and then select the ending voltage, that is all.

Ending voltage maybe put it as 2.8V?

Thanks 2100, can you also select the voltage?

It depends on the exact hobby charger being used.

Most will have voltage settings for LiFe cells (can't remember off the top of my head, as I never use it myself, but it'll be 3.6 or 3.7v CV), a setting for LiCo/LiMn cells (4.1v) and a setting for LiPo packs (4.2v). Most modern LiCo/LiMn cells can actually be charged to 4.2v without any issues, though the 4.1v setting would tend to make the cells last longer with little loss of stored energy.

Some higher end chargers also allow you to fine adjust the preset CV values, whereas cheaper chargers will have entirely fixed presets. For instance, the iCharger range of hobby chargers will allow the LiPo setting to be adjusted up to 4.30v, allowing you to use more of the potential capacity of some of the newer Samsung and Sanyo li-ion cells that have peak CV values of 4.30 and 4.35v.

Thanks Stephen,

From your comment I understand the charger should be able to be cofigured for some given chemestries (Li-Po,LiFe-Po;Ni-Mh etc) or if it is a good one, it would be possible to adjust the voltage manually.

What I was asking for is for the discharge test, just in case you meant the charging parameters.

Aah, gotcha, thought you were referring to charging rather than discharging.

Same situation - cheaper hobby chargers tend to have a fixed value for the discharge cut-off value of li-ion cells, whereas better ones can be adjusted. 3.0v is normally the cut-off value for li-ion cells.

What a lot of people do if they want to discharge below 3.0v, and have one of the simpler hobby chargers, is to use the NiMH discharge function, which is normally fully adjustable. Honestly though, unless looking to test the full capacity of a cell that is specifically advertised to discharge to a lower voltage, I would personally stick with discharging down to 3.0v.

There is no harm to your li-ion cells in using the NiMH discharge function, as long as you stick within sensible parameters for the cut-off value. However, you should never charge li-ion cells with the NiMH charge function, or vice versa.

hello Steven,

I am missing something dischargin them while selecting Ni-Mh, is it discharging the cells at 1.2V and 1A, or you can tell the charger to discharge 3 Ni-Mh in series to get 3.6V@1A?

It might be a silly question, but it is something I do not understand, and as I see Li-Po batteries are nomally made of series and parallel cells at the same time..

In NiMH discharge mode, you tell the charger what voltage to discharge to, and that voltage is for the complete pack, not voltage per cell within that pack.

Normally with NiMH cells, you would discharge a single cell down to 0.9 or 1.0v. That means that if you if you set the charger incorrectly, and set the per cell discharge cut-off, rather than the cut-off voltage for the whole pack, you could try and discharge a complete battery pack down to 0.9v, which is obviously going to hugely over discharge each and every cell. For instance, if I were going to discharge the 12AA battery pack in my Mag623, to 1.0v per cell, I would need to set the cut-off voltage to 12v - 1.0v per cell, with 12 cells in series. The charger will do whatever you set it to do with the NiMH discharge function.

So with your example of 3 NiMH cells in series, discharging each cell to 1.0 or 0.9v, you would set the charger to discharge down to 3.0v or 2.7v. You also set the charge to discharge at the rate you chose, as the rate is also adjustable. Again you find a difference between cheap and more expensive chargers. Cheap ones generally have a lower maximum discharge rate - 1.0A max is a common limitation. More expensive chargers often have a built in fan to cool the charger, allowing them to be set to higher discharge rates without overheating the charger, and so they can normally be adjusted to higher setting than cheaper chargers without a fan.

With regards to battery packs with a combination of cells in series and parallel, you multiply the number of cells in series to work out the voltage of the pack, and the number of cells in parallel is multiplied by each cells capacity (assuming all cells have the same capacity individually) to calculate the total capacity of the pack. For instance, if you had nine 2000mAh AA Eneloops, arranged in a 3S3P pack, you would have a battery pack with a nominal voltage of 3.6v (3S) and a capacity of 6000mAh (3P). If you were to discharge that pack down to 1.0v per cell, you would set the charger to discharge down to 3.0v, as voltage is dictated by the number of cells in series, not the total number of cells in the pack.

Got my King Kong cells yesterday and here are my first tests at 3Amps:

Cell #1: 4191 mAh

Cell #2: 4087 mAh

Cell #3: 4233 mAh

Best MKNE (from TacticalHID) first test @ 3 Amps : 3989 mAh

The KK have quite a "knee". That make me think these should have no problem with serious amps.

Thanks a lot for the explanation, I will tell my friend to do it following this criteria.

Wow...looks real good at 3A too at 4.2AH and i suppose your room is quite cool too? If running at 1A / medium and the cell is kept warm (well my country is always warm heh), probably get close to my results. I digged it down to about 2.7-2.8V too and the knee might extend a bit and not fall off as sharp as at 3A.

The MKNE IMR doesn't even flinch and experience any change in capacity at 3A. I got ard the same numbers as you at 1A.

68F/20C. Since I intend on using these in the JM07 PRO, this is really highest amperage test I needed to see, but for the sake of science I’ll push them harder tomorrow. :slight_smile:

EDIT: Another interesting thing to think about is the additional POWER of the 26650. Its not just the Ah, it is the watt hours. We've got 3.1Ah 18650s and the 26650 only bumps it up over 4Ah, BUT if you take voltage into account, the story is a little different.

Now I'm making up my own rules a bit, but If I compare my best Panasonic 3100 to my MIDDLE KK 26650 at 3A and cut it off at 3v the power is 8.90Wh vs 14.82 Wh. That means in that particular example, the 26650 has 66% more power than the 18650. If the cut-off was set lower the 3100 would gain a little on the 26650, but I think 3v is reasonable. The advantage is also very similar over a Sanyo 2600.

I like the king kong name, sounds awesome

Well, temperature plays a small but noticeable part. If you are discharging a JM07 at 20 deg C ambient @ 3A, the cell would definitely discharge at at least 50 deg C after 10 minutes. :) My JM07 does 2.6A, btw.