Now let's look at the middle part of the test. At this point it's worth considering that the slightly lower performance of the VTC5 is simply because of the lower charge it started with. The only reason the 25R and VTC5 show better voltage numbers is because they still have more charge left in the battery. As you can see from the table, the voltage sag from the different batteries are all pretty much identical especially when converted to internal resistance. Here's a table of the voltage sag under load and a calculation of the internal resistance at this point. You can see the 25R has the highest voltage, followed by the VTC5, followed by the VTC4. Let's look at one pulse close up, 200 seconds in. The VTC5 continues to be just slightly worse than the others both under load and off load.Īround the 20th pulse or so a clear difference starts to emerge. However it shows less sag in this region than the 25R so under load they're about the same. After a few pulses though the VTC4 starts to show its lower mAh and by 8-10 pulses in you start to see a bit of a difference at max voltage with the 25R winning. The VTC5 starts at a very slight disadvantage being at 4.18V instead of 4.2V like the others but still even with that considered it sags further than the others and drops in voltage quicker than the 25R. So let's look at the first part of the test in more detail.Īs you can see in the very beginning the VTC4 and 25R are right on top of each other. Here's an overview chart of how the test turned out:Īs you can see from the overview, the 25R lasts the longest, followed by the VTC5, followed by the VTC4. Both power and current decrease as the voltage drops as the test goes on since it's constant resistance. This will mean current levels will vary from 16-21A and power will vary from 51W-88W, per battery. This is done from full charge (4.2V) until the voltage goes to 3.2V. The device is fired for 3 seconds, then turned off for 8 seconds, then repeated. This test simulates a mechanical mod or other constant resistance load of 0.2 ohms with one lithium ion cell (3.0-4.2V). So how do the 25R, VCT4, and VCT5 perform with 0.2 ohms? The Test: 3 second load pulses of 0.2 ohms After verifying there wasn't a huge difference, the data for the new ones will be shown below. All batteries we tested at least one new one as well as a couple that had been lightly used and stored for a bit. ![]() The Samsung 25R is the new green Samsung, the 25R5. The test will be at the top end of the rating of the Samsung and the VTC5 (they are rated 20A continuous), while being mid-way through the rating for the Sony VTC4 (pretty much the only battery that's truly rated for 30A continuous). The batteries under test are the Samsung 25R (full part number INR18650-25R), the Sony VTC4 (also known as VCT4, full part number US18650VTC4), and the Sony VTC5 (also known as VCT5. So we decided to do a comparison test of the voltage drop under this significant constant resistance load, comparing the Samsung 25R vs Sony VTC4 vs Sony VTC5. The results are very applicable to someone using a regulated (constant watts) device as well. ![]() One question we get particularly from the e-cig crowd is which battery will show less voltage sag and perform better under pulses at a specific ohm level, for example in a mechanical mod device.
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