Measured internal resistance on my new batteries

[Alessandros]

Hi everyone,

You may recall (or simply see lower in the board) my post asking for high-quality battery suppliers shipping to Canada. Well, I went with Illumination Supply. Shipping was pretty quick, and the packaging was nice. Measured internal resistance after charging them, and, well, a little disappointed with Nitecore. :undecided:
I guess it's nothing but 18650's for me in the future!

Here's the imgur album: New batteries - Imgur

Thanks for taking a look here.

 

[Marco Polo]

I could be wrong about this, but are you sure the batteries are in the correct position in the charger? IIRC with that charger you should put similar cells in slots 1 and 3, or 2 and 4, rather than side-by-side as you have them. It might not be charging the 18650's properly if that is the case. I could be wrong about that, but that is what I recall from reading a bit.

I note that the initial voltage (no-load voltage) seems low; full charge is ~4.2 and by the time you get to 4.0 volts the cell is well on its way to being discharged and might sag a bit more under load.

What results do you get when testing the 18650's at full charge?

 

[grainde]

Try measuring the resistance from 4 V not 4.2 ish, the curve is rather steep between 4.2 and 4 V. Have a look at my posts in the Dr Lava battery resistance thread for more info.:beer:

 

[RYDorDIE278]

Hi everyone,

You may recall (or simply see lower in the board) my post asking for high-quality battery suppliers shipping to Canada. Well, I went with Illumination Supply. Shipping was pretty quick, and the packaging was nice. Measured internal resistance after charging them, and, well, a little disappointed with Nitecore. :undecided:
I guess it's nothing but 18650's for me in the future!

Here's the imgur album: New batteries - Imgur

Thanks for taking a look here.

Hey i used this resistor for 18650s 4 Ohm 4R 5W Watt Power Metal Shell Case Wirewound Resistor | eBay and got very good consistent results with 18650s, i guess you could run two of your resistors in parallel to load the 18650 cell , but generally it should be loaded capacity/3 acording to this thread http://laserpointerforums.com/f67/h...-how-measure-internal-resistance-57576-4.html i just think the 10ohm resistor might be too much load for the cr123s and definitly too much load for the 10440, im not 100% sure but i would say you will be sagging the smaller cells voltage too much, your 18650 results dont seem too bad though

 

[Alessandros]

IIRC with that charger you should put similar cells in slots 1 and 3, or 2 and 4.
Full charge is ~4.2 and by the time you get to 4.0 volts the cell is well on its way to being discharged and might sag a bit more under load.

Try measuring the resistance from 4 V not 4.2 ish

Tried the staggered positioning of my batteries, still not seeing them reach 4.2V... I'll check Dr. Lava's thread.

Hey i used this resistor for 18650s 4 Ohm 4R 5W Watt Power Metal Shell Case Wirewound Resistor | eBay and got very good consistent results with 18650s, i guess you could run two of your resistors in parallel to load the 18650 cell , but generally it should be loaded capacity/3 acording to this thread http://laserpointerforums.com/f67/h...-how-measure-internal-resistance-57576-4.html i just think the 10ohm resistor might be too much load for the cr123s and definitly too much load for the 10440, im not 100% sure but i would say you will be sagging the smaller cells voltage too much, your 18650 results dont seem too bad though

Hmm, didn't think too little current would yield bad results. I'll grab a lower resistance load soon.

Thanks for the responses!

 

[LarryDFW]

Alessandros;

Your 4 ohm resistor is fine for testing . . .

With my new analysing charger, I check I.R. every time a cell is inserted for charging.

The good 18650's (Sanyo and Panasonic) are down in the 50 milliohm range consistently.

According to 18650 Battery Testing Experts @ Cadex :

75-150 mOhm - Excellent
150-250 mOhm - Good
250-350 mOhm - Marginal
350-Up mOhm - Bad

LarryDFW

 

[RYDorDIE278]

Alessandros;

Your 4 ohm resistor is fine for testing . . .

With my new analysing charger, I check I.R. every time I charge a cell.

The good 18650's (Sanyo and Panasonic) are down in the 50 milliohm range consistently.

According to 18650 Battery Testing Experts @ Cadex :

75-150 mOhm - Excellent
150-250 mOhm - Good
250-350 mOhm - Marginal
350-Up mOhm - Bad

LarryDFW

I think hes using 10ohm resistor, im using 4ohm resistor..
what charger are you using? im still waiting on my "dreamcharger" awesome features to measure capacity and resistance in a charger!

 

[paul1598419]

I noticed that it was stated that the increased resistance of a 10 ohm resistor versus a 4 ohm resistor was called an increase in the load. The higher the resistance, the lower the load. Think of it this way, a 1 megohm resistor would be a huge "load" compared to a 1 ohm resistor. That is backwards. The lower the resistance the greater the load.

 

[RYDorDIE278]

I noticed that it was stated that the increased resistance of a 10 ohm resistor versus a 4 ohm resistor was called an increase in the load. The higher the resistance, the lower the load. Think of it this way, a 1 megohm resistor would be a huge "load" compared to a 1 ohm resistor. That is backwards. The lower the resistance the greater the load.

I dont think we called it that, might be a little confusion because i was recomending 2 things at once
*increase the load for 18650(from 10ohm)
*decrease the load for cr123/10440(from 10ohm)

 

[paul1598419]

I'll take your word for it. It seemed strange to me the way it was worded, but I have made the same mistake in wording myself. So, I apologize if I misunderstood your meaning.

 

[LarryDFW]

what charger are you using? im still waiting on my "dreamcharger" awesome features to measure capacity and resistance in a charger!

This new 2-Cell charger . . .

Charges 18650, 26650, 16340, and 14500 Lithium Ion Cells
Selectable Charging Current of 1/2 amp or 1 amp on each channel
Discharges Cells to Determine Capacity
Analyses Cells to Determine Internal Resistance

Comes with 115 VAC adapter, but also works off 12 VDC from vehicle.

Pretty amazing technology, at a reasonable price point - $36.95 frt ppd in cont. US

LarryDFW

 

[RYDorDIE278]

I'll take your word for it. It seemed strange to me the way it was worded, but I have made the same mistake in wording myself. So, I apologize if I misunderstood your meaning.

Hey no worries paul! my bad grammar/wording..

This new 2-Cell charger . . .

Charges 18650, 26650, 16340, and 14500 Lithium Ion Cells
Selectable Charging Current of 1/2 amp or 1 amp on each channel
Discharges Cells to Determine Capacity
Analyses Cells to Determine Internal Resistance

Comes with 115 VAC adapter, but also works off 12 VDC from vehicle.

Pretty amazing technology, at a reasonable price point - $36.95 frt ppd in cont. US

LarryDFW

Yea not too bad alright, i wish there was a cheap smart charger that fit 32650s aswell!