Sony VTC5 or US18650VTC5 is a 2600mAh 18650-size Li-ion cell which supports continuous discharge at up to 30A with 80°C temperature cut or up to 20A with no temperature control. VTC5 can hold up to 100A pulse discharge for <3 seconds.
The battery was bought from Queen Battery which is my reliable supplier of genuine cells and tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.
I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals
I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle the battery was charged at standard charge current mentioned in its datasheet to charge end voltage. Before each discharging or charging i've held a 1-1.5hr pause. The environment temperature was 25±2°C. To be sure in results i've done each test minimum twice (usually 3-7 times).
SONY US18650VTC5
The heat shrink tube carries the following marking: SE US18650VTC5 C5 G 0173736ZC19U which tells that the cell was manufactured on 19 March 2017 by Sony Electronics (Singapore).
DC IR at 2500mA in fully charged condition was 14.6±1mΩ (measured using EB Tester Software's Resistance test feature).
Measured dimensions: 18.2mm (diameter) × 65.0mm (length).
Measured weight: 44.12g.
SONY US18650VTC5
The heat shrink tube carries the following marking: SE US18650VTC5 C5 G 0173736ZC19U which tells that the cell was manufactured on 19 March 2017 by Sony Electronics (Singapore).
Sony VTC5's main specifications according to its datasheet (pdf):
Rated capacity: 2500mAh (0.2C, 2.0V cut-off)
Nominal capacity: 2600mAh (0.2C, 2.0V cut-off)
Nominal voltage: 3.6V
Standard charge current: 2.5A
Charge end voltage: 4.20±0.05V
Max charge current: 4A
Ambient temperature range during charging: 0–60°C
Recommended charge end voltage at <10°C and >45°C: 4.15V
Max continuous discharge current: 20A (8C) / 30A (12C) with 80°C temperature cut
Max pulse discharge current: 100A during <3sec
Discharge cut-off voltage: 2.5V (2.0V for 0.2C)
Ambient temperature range during discharging: -20–60°C
AC impedance at 1KHz: 8-18mΩ
Weight: 44.3±1.5g
Cycle life: After 300 cycles at 4A charge with 100mA cut-off then 10A discharge with 2.5V cut-off the capacity should be ≥1750mAh (70% of rated capacity).
DC IR at 2500mA in fully charged condition was 14.6±1mΩ (measured using EB Tester Software's Resistance test feature).
Measured dimensions: 18.2mm (diameter) × 65.0mm (length).
Measured weight: 44.12g.
Sony US18650VTC5 capacity test results:
First of all, look at the discharge cut-off voltage at 0.2C - it's 2.0V because Sony uses it for rating its cell. At all other discharge rates 2.5V was used by Sony and by me too. I don't understand why Sony does that because the capacity carried between 2.5V and 2.0V is miserable - just look at the violet curve.
Whatever, let's pass to the results. At 0.2C or 0.5A using 2.0V discharge cut-off VTC5 showed 2665mAh - a very expected good result. At all other discharge rates, as i told, 2.5V cut-off was used. At 5A discharge the capacity was slightly below 2500mAh but at 10, 15 and 20A it was above it. The curves look good, almost linear.
Comparison with Samsung 25R
Samsung INR18650-25R is a 2500mAh 18650 cell supporting continuous discharge at up to 20A. Not exactly the same spec as those of VTC5 but i think it's interesting to compare them.
At 5A discharge:
Their curves are almost identical! VTC5's capacity is only 10mAh higher while 25R is ahead in energy by 18mWh.
At 10A discharge:
Look at those curves - they go head to head down to 3V but then Sony VTC5 starts to show who's the better cell. So the difference in the end is 58mAh/173mWh in VTC5's favor.
At 15A discharge:
The picture starts to change - all the way down to 3V 25R's voltage stays higher but then it goes down faster than Sony's resulting in 64mAh/135mWh difference in favor of Sony's cell.
At 20A discharge:
Almost the same situation as at 15A discharge but 25R's voltage is less higher than VTC5's and they exchange roles at 2.95V. The difference is 96mAh/226mWh again in VTC5's favor.
So who's the winner? The results are so close and the difference so small that i can't answer to this question. I prefer to say there is no clear winner and both cells are good at all discharge rates.
Verdict
Sony VTC5 is a real 2600mAh high-drain cell and there is no surprise because Sony is a top league player. 2.5V discharge cut-off makes VTC5 compatible with almost any BMS and 100A pulse discharge during up to 3 seconds makes it an excellent cell for power tools and e-cigs. Vapers will be happy:)
Here is the video version of this review: