Green Samsung 18650 25R5 vs. Blue 25R2

Battery Bro was requested for clarification to differentiate between the grim 25R along with also the green 25R.

When asked, Samsung SDI reacted with the following model names:

Blue version: Samsung 25R2
Green version: Samsung 25R5

What is the distinction between the green and blue Samsung 25R 18650?

They delivered a scanned letter-of-guarantee to your brand new Samsung 25R5. Here are the important components referenced:

Samsung SDI ensures that the functioning of the 25R2 with blue PVC and 25R5 with green PVC are completely same.
The Proportion of Electrolyte is alter compared to 25R5

FEC: 3 -> 5 percent
SN: 1.5 -# 1 percent
PA77: 1-> 1.5percent

The life span could be greater than 25R5
Bottom-line: The green Molicel 18650 a much better cycle life.

A bicycle is one complete charge and discharge of the battery life. If someone asked you how old a battery is, then you need to reply by telling its cycle count. So what’s the cycle lifestyle the 25R? A Fast check of this spec sheet yields the response:

The 25R2’s lifestyle is: 250 cycles. This is analyzed at 20A, the mobile’s max. Continuous discharge score.

Following 250 cycles the highest capacity the 25R2 could hold drops to 1500mAh or reduced (that is at 60 percent of its own launching capability, at 25℃).

So we can state that the 25R5 includes a cycle life larger than 250 under the very same problems.

A closer look in the chemical changes which go into the Samsung 25R5.

Samsung recorded three distinct chemical tweaks such as its 25R5 – FEC, SN, and PA77.

Molicel 18650

FEC: Fluoroethylene Carbonate

Samsung 18650 25R2 (blue): 3 percent
Samsung 18650 25R5: (green): 5 percent
This newspaper printed in 2011 from the American Chemical Society clarifies the impact of FEC on battery functionality in lithium battery electrolyte compositions.

When batteries are cycled you will find a tiny impurities, that time decrease the capacity of this mobile. That is the reason why batteries don’t last forever.

Each time you control or release your 18650 battery powered (biking ), you’re ruining nanoscopic structures which store pieces of electricity.

In this picture you can see the structural and functionality differences to a electrolyte using FEC added. The reddish (b) and green (c ) ) lines comprise FEC, their traces never dip under a 1000mAh capacity, as well as the photographs show materials that are structurally more complex and exact. The shameful (a) lineup is almost depleted by bicycle 35.

Scientists have a look at different morphologies of this battery chemistry with graphics such as these. For fun, see If You’re Able to identify some of the following traits from the picture:

nanofibers
nanotubes
nanowalls
nanocones
nanoflakes
nanoshafts
In this paper, scientists generated NiO (nickel oxide – a transition-metal) that is nancuboid (little, cube-shaped). The wonderful clean and sharp edges which compose the nickel oxide cubes are intriguing as they can release energy in a high speed (high amp charge/discharge), and store a good deal of energy (high ability ). They implemented FEC (fluoroethylene carbonate) as an additive into the cubed nickel oxide, which generated better biking stability.

Some seriously amazing nano cuboids are revealed here. Both of these pictures courtesy of the newspaper connected to earlier.

The FEC addition provides the nano-cuboids better functionality, and also the degradation brought on by biking your battery is diminished. They discovered NiO is comparatively stable before its 35th cycle, even in which a sharp drop in ability is detected. The fall is attributed to the degradation of the NiO – especially it undergoes a response which has large volume changes that cause fractures, decrease conductivity, and pulverize the electrode. Once an FEC additive was released, fantastic developments to capacity were detected: the dimension being nearly twice the theoretical capability of NiO. The changes have been attributed to nanoscopic morphologies however, the exact reasoning isn’t well known.

Bottom-line: Adding FEC raises the cycle life of li-ion batteries.

SN: Succinonitrile

Samsung 18650 25R2 (blue): 1.5percent
Samsung 18650 25R5: (green): 1.0percent
This newspaper from 2014 clarifies the impact on a mobile’s impedance (a dimension of immunity ) as soon as the electrolyte involves an SN (succinonitrile) additive.

In conclusion, adding SN into the electrolyte considerably enhanced the impedance (resistance) expansion during biking. As lithium-ion batteries era, not merely does ability return, but inner resistance goes up. This makes it increasingly challenging for lithium-ions to stream, and puts added strain on the battery causing additional degradation.

Hence that the SN electrolyte really increases battery immunity between bicycles. By cutting the total amount of SN from the Samsung 25R5, Samsung SDI has also diminished the 25R’s impedance development.

Bottom-line: Decreasing SD will maintain immunity low, for more.

Molicel 18650

PA77: Unknown

Samsung 18650 25R2 (blue): 1.0percent
Samsung 18650 25R5: (green): 1.5percent
Really I can get no information regarding this additive within an electrolyte, therefore I think it’s likely Samsung SDI proprietary study. They’ve improved the equilibrium of this PA77 compound in the 25R5 electrolyte, and I presume it enhances cycle life somehow but I do not understand how.

Could the secret of this green 25R5 be… protactinium?

PA (protactinium) is quite toxic and an extremely radioactive chemical element, but is found in tiny quantities in most organic things. We eat it, drink it, and breath . Government even modulates the sum of permitted PA from the atmosphere. Samsung SDI said”PA77″ since the compound in the letter-of-guarantee, where generally the’77’ should denote the component’s isotope amount . It’s likely Samsung utilizes a distinctive isotope of protactinium that’s quite secure called protactinium-77.

However, there isn’t any sign of this, anyplace.

Argonne National Lab, retains tens of thousands of unmanned patents. They’ve devised some of the most frequently utilized 18650 chemistries such as NCR, and let them out to other people such as Panasonic. Due to the compound protactinium’s lack, higher radioactivity, and higher toxicity Argonne Labs said in 2005 that PA does not have any use beyond scientific study.

So has Argonne begun placing it in batteries because then?

It is possible because I can not think of everything else that the PA77 would refer to. When it followed the exact same naming convention as the other two compound adjustments, all roads lead to the decision. However it can just be something entirely different. If you’re a chemist or battery powered scientist which has a different concept, please send me a message! I’d really like to reach the bottom of the.

A reader has pointed out there is not any way protactinium may be from the batterylife. This makes sense to me personally, but in addition it means I don’t have any clue what PA77 may refer to.

Bottom-line: I really don’t understand what PA77 is.

Doing some ability tests on the Samsung 25R5 (green)

Samsung guarantees functionality will be equal to the 25R, so I conducted some discharge tests before to confirm their announcement as part of the supply-chain review procedure.

My testing environment is great and requirements match Samsung’s testing requirements :

Unless otherwise specified, all evaluations said in this specification are conducted in temperatures 25±5℃ and humidity 65±20%.
The amp-meter and volt-meter ought to get an accuracy of this caliber 0.5mA and mV or greater.
Actually we’re just 30 levels, the 1.5 level extra is arriving from the picture lamps.

Ahead of the release tests I needed to charge the cells up. Samsung shops the 25R in 50 ±5 percent charged condition (from 3.640V to 3.710V). As soon as I received them which has been the situation in accordance with my Soshine charger – oblivious of brand-new cells.

The first two tests I conducted are in a constant release of 2.5A – that is our benchmark here for release tests since it is the top limit of what a USB drive provides for electricity, and we chart via USB for pace.

Total Capacity: 2525mAh
Total Energy: 8725mWh

Total Capacity: 2523mAh
Total Energy: 8767mWh

Very Great! The mobile readily surpass manufacturer specs – having the ability to provide greater capacity than graded, in a greater discharge current than analyzed for.

The next test is conducted to compare more carefully manufacturer specs. The Samsung 25R is formally discharged at .2C or even .50 amps to accomplish its rated capability. That is low, since most 25R usage is optimizing its maximum. Continuous release rating of 20A. But that’s the way all 18650 cells have been rated for power, at a minimal workable drain. The further amps you draw, the total capacity generally can be obtained. This is referred to as a reduction of efficacy, and the efficacy dropped from high-drain situations ranged between different chemical makeups.

Here’s the Samsung 25R2 in .50A:

Total Capacity: 2524mAh
Total Energy: 9051 mWh

Molicel 18650
Have a look, it is interesting. In .50A the resolution of this release curve gets more comprehensive. It is possible to view three distinct peaks in voltage. Every of the voltage peaks is accounted for by a substance modification within the battery.

You might have discovered the capacity remained the same, however the entire energy increased.

How can this be?

By overlaying the charts we could certainly see where the gap is:

A 0.10 volt gap between the sparks.

And this everyone, is precisely why ability ratings could be misleading. Both releases began, and ended in the exact same moment. They followed the exact same route, except the 0.50A discharge remained 0.10V greater than the 2.5A-discharge. Exactly the very same amps, for exactly the identical period of time, albeit in another voltage can be in turn a greater overall energy.

Analogy: Imagine that a sink and a beaker. The beaker is quite lengthy and quite thin – such as an elongated pen. You wish to fill up it with the faucet. However, each drop of water wasted is precious energy dropped. Should you turn the faucet on full-force you’ll fill the beaker fast, but water will dash and lots of drops will escape. So what exactly do you do? You bring down the faucet to a trickle, and you may actually catch all of the water.

Most batteries do lose ability when they’re discharged using a greater present. The simple fact that the 25R5 loses no potential involving a.50A and 2.5A release is an outstanding attribute. Mature battery chemistries (only a couple of years back ) weren’t this efficient.

The functioning of the 25R5 is actually outstanding.

Difference between the 25R2 and 25R5

A typical release evaluation to get a 25R2 (with equal conditions as 25R5 evaluation 2 & 1 ).

Here you can view both the energy and capacity of this 25R2 is a bit less than the 25R5. That general, seems accurate, albeit only marginally. I’ve analyzed some Grade A 25R2 batteries that transcend this 25R5’s stats.
Since Samsung SDI initially stated, the most important difference between the blue Samsung 25R along with also the green Samsung 25R is the higher cycle life. A little ability profit, or efficiency advantage might be a side-effect of enhanced chemistry (the 25R5 has two decades of study within the 25R2 therefore that it’s not so farfetched ).

Visual Inspection

The Samsung 18650 25R we’ve have been speaking about in all of its glory. Let us go through a Fast check list:

Scratches: None
Rust: None
Discoloration: None
Leakage: None
The diameter is 18.3mmcheck.

The elevation is 64.9mmcheck.

IMPORTANT: Digital calipers are recommended by Samsung with this evaluation – but you need to remember to not use metallic calipers since they might short-circuit your mobile.

I weighed both batteries, they’re identical in weight that’s quite great to see. Really I totally charged one, and completely discharged another since I wanted to see whether there are a burden difference. Just to be clear, I speculated that no difference… also it will turn out the instance is that there’s not any difference.

You may remember from the last article about the Samsung 25R, which Samsung top caps have three connection points.

I took the PVC off this one. These superior control markers can be observed via the PVC using a keen eye.

The unique external attribute of this 25R2 along with the 25R5 will be the etchings at the bottom of this negative terminal of the battery life. This battery comes with an’H10′, and I had to pare the PVC slightly to view it. No additional 18650 battery chain I’ve seen except that the 25R has this (however that might be because I have not seen sufficient ).

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