Search results

Date Relevance Most replies

  1. B

    Influence of DOD and temperature on the internal resistance

    This are different tests. First is test for internal resistance ( around 7000s), second is pulse mode tests (around 4000s).
  2. B

    Influence of DOD and temperature on the internal resistance

    Another 2 cell from LiPo Graphene 1.5Ah 65C pack is added. After 2 cycles with +1A / -1A and 3 cycles with +2.3A / -4A: Cell2: 1487 mAh from SkyRC B6 @1A; 1453 mAh from the battery tester 0.9A / 8A; Cell3: 1490 mAh from SkyRC B6 @1A; 1465 mAh from the battery tester...
  3. B

    Influence of DOD and temperature on the internal resistance

    I will try to do that soon.
  4. B

    Influence of DOD and temperature on the internal resistance

  5. B

    Influence of DOD and temperature on the internal resistance

    My DCIR measure pulse is 10 seconds with 8A. This is near to C/100 for 2.2Ah cell. Maybe you mean my ACIR test pulse - 1.05 ms with 8A or C/ 7 500 000 for 2.2Ah cell.
  6. B

    Influence of DOD and temperature on the internal resistance

    What kind of information gives C/200 DCIR ? No load voltage drop when cell lose some of its capacity. This is not happening bеcаuse of the internal resistance.
  7. B

    Influence of DOD and temperature on the internal resistance

    LiPo Graphene 1.5Ah 65C is added. After 2 cycles with +1A / -1A and 3 cycles with +2.3A / -4A: 1492 mAh from SkyRC B6 @1A; 1467 mAh from the battery tester 0.9A / 8A; Pulse test: 4.1V - 3.4V C= 1265 mAh; E= 17379 J; pulse counter=58; Weight of one naked cell: 42.71 g
  8. B

    Influence of DOD and temperature on the internal resistance

    A123 26650m1b is added. 2530 mAh from SkyRC B6 @1A; 2470 mAh from the battery tester 0.9A / 8A; Pulse test: C= 2245 mAh; E= 25819 J; pulse counter=101; Weight: 75.55 g
  9. B

    Influence of DOD and temperature on the internal resistance

    VTC5A is added. 2460 mAh from SkyRC B6 @1A; 2400 mAh from the battery tester 0.9A / 8A; Pulse test: C= 2029 mAh; E= 26111 J; pulse counter= 89; Weight: 47.34 g
  10. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    Yes, mOhm*gram is correct.
  11. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    Simple example: One cell with 2Ah, 20 mOhm have 40 mOhm /Ah because when are connected two cell in parallel each with 1Ah, 40 mOhm summary capacitance will be 2Ah and internal resistance - 20 mOhm. ...Resistors in paralel: R12 = (R1*R2) / (R1+R2).
  12. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    Here are my testings of 30Q. https://endless-sphere.com/forums/viewtopic.php?f=14&t=73701 I see some differences, but is close to DCIR.
  13. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    How is measured the internal resistance?
  14. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    The charger measure only AC internal resistence and also the measurement is inaccurately. In your case the voltage sag is linked to DC internal resistence and DCIR > ACIR. Your calculation is wrong . 8 mOhm for 5Ah is equal to 40 mOhm/Ah.
  15. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    Easy calcs... 3S 1300 mAh turnigy nano 25-50C weight 139g, or 46.3g per cell. Dc internal resistence will be approximaly 7.7 mOhm or 166 mOhm /g and 37 mOhm/Wh. VTC5A have 377 mOhm /g and 152 mOhm/ Wh. Soon I will make a test on some lipo and I can tell with sure.
  16. B

    Samsung 30Q INR18650-30Q 3000mah 15a cell

    VTC5A has low DC Internal Resistance but lipo has less (approximately 10 mOhm/Ah).
  17. B

    Influence of DOD and temperature on the internal resistance

    From second test on MJ1 I measure internal resistance with 0.5 mOhm higher and updated the upper post. I have started the pulse mode tests @8A, 10s on /30s off. All cells will be charged to 4.1V, 0.2A cut off. The end voltage is 2.9V. Room temp 23*C +/- 0.5*C. MJ1: C= 2409 mAh; E= 29627 J...
  18. B

    Influence of DOD and temperature on the internal resistance

    Yes, I can. I have repeated some tests for the Influence of the DOD and the differences is little mostly because of the different temperature in the room. Edit: I will repeat the test for influece of temp for MJ1 without tabs, because of each tab bring 0.7 mOm and I don't sure in my...
  19. B

    Influence of DOD and temperature on the internal resistance

    30Q vs HG2: GA vs MJ1: 25R vs VTC4:
  20. B

    Influence of DOD and temperature on the internal resistance

    The Influence of the temp on the internal resistance with a minimal influece of the DOD. All cells will be charged to 3.8V, 0.2A cut off. 1. 30Q (new):
  21. B

    Influence of DOD and temperature on the internal resistance

    Sorry for late answer. I have limitation and don't want to damage my cells. But maybe in future I will make tests in extreme conditions. In last chart (for 30Q) near to 35% DOD, DCIR rise up with 1 mOhm because opening of a window in the room and the temperature drop with 2 *C.
  22. B

    Influence of DOD and temperature on the internal resistance

    5.HG2 (new): 2930 mAh from SkyRC B6 @1A; 2891 mAh from the battery tester 0.9A / 8A; 6.30Q (new): 2950 mAh from SkyRC B6 @1A; 2938 mAh from the battery tester 0.9A / 8A;
  23. B

    Influence of DOD and temperature on the internal resistance

    The internal resistance is the most important factor defining the efficiency of the battery. But the data for the internal resistance of a specific battery is incomplete. In pdf's of some batteries there is some information such as: "Internal Resistance - less than 38mOhm/ AC impedance 1 kHz"...
  24. B

    Used Makita pack teardown

    I have19s US18650V from 36V/2.6A/h bosch battery brand 2009. Now capacity is 870 mA/h and 75 mOhm internal resistance for each cell...
  25. B

    Samsung 25R/LG 18650HE2/ Sony VTC5 high power 18650 battery

    In the end of the discharging chart the internal resistance is increased. Sometimes, in remaining 10% of the capacity, the change is bigger than 50%. I have made many test of Li-based battery and without the influence of the temperature - the internal resistance doesn't change above of 10% for...
Back
Top