Best 18650 battery (with criteria)

[N/Apower]

I do not know of course, but my theory is if they told the truth people would not believe it, "everyone knows" batteries have some self-discharge rate, and they think their specs would lose credibility?

https://uwspace.uwaterloo.ca/bitstream/handle/10012/12177/Catton_John.pdf?sequence=3&isAllowed=y

file:///D:/Downloads/energies-11-03295.pdf

Given the massive capacity difference, I am inclined to go with non LFP cells, as even the slight increase in degradation will still put me far ahead in a timeframe I am interested in. I may well buy some LFP cells to T&E, though!

 

[john61ct]

Yes for sure LFP does not compete where high energy density is a priority over lifespan or self-discharge.

Between the various 3.6-3.7V chemistries,
NMC
NCA
LCO
LMO

I am sure there are huge differences in the self-discharge attribute, but I have not seen much in the way of quantified data there.

Just recognize you are now moving away from this goal:

what battery will have the longest shelf/storage life if charged up and simply left in the light/storage for years, given all of my criteria EXCEPT capacity/mah? Is the answer the same, or is there a lower mah battery that meets the other criteria that has much better chemistry for "We need these on point in 20 years..."

A few years, sure no problem, but personally I would not go to the 3.6-3.7V chemistries if literal decades were required.

______

Does this mean a 3300mah battery would perform equal to a 3000mah battery with a full charge, if charged to 4.1V?

Need to specify which attribute of "performance" you are asking about.

The lower stop-voltage factor is not as significant to longevity as average DoD%

As low as 4.05V will work better than 4.15V, but how much mAh capacity you are sacrificing will vary by chemistry of each cell.

Pushing to the maximum capacity - rated voltage held for CV/Absorb stage until current trails to say 0.01C - is definitely life shortening.

But doing so a few cycles only occasionally will not have a great impact, as with draining to 3.1V

one event in itself is not "damaging"

it is the average treatment over all the cycles that is important.

 

[Climb14er]

The Sanyo Pannys from Japan are excellent. The Sonys are also very good. Buy from a reputable vendor and don't worry. The cells available these days are inexpensive and very good.

 

[N/Apower]

Yes for sure LFP does not compete where high energy density is a priority over lifespan or self-discharge.

Between the various 3.6-3.7V chemistries,
NMC
NCA
LCO
LMO

I am sure there are huge differences in the self-discharge attribute, but I have not seen much in the way of quantified data there.

Just recognize you are now moving away from this goal:

A few years, sure no problem, but personally I would not go to the 3.6-3.7V chemistries if literal decades were required.

______


Need to specify which attribute of "performance" you are asking about.

The lower stop-voltage factor is not as significant to longevity as average DoD%

As low as 4.05V will work better than 4.15V, but how much mAh capacity you are sacrificing will vary by chemistry of each cell.

Pushing to the maximum capacity - rated voltage held for CV/Absorb stage until current trails to say 0.01C - is definitely life shortening.

But doing so a few cycles only occasionally will not have a great impact, as with draining to 3.1V

one event in itself is not "damaging"

it is the average treatment over all the cycles that is important.

Mainly LFP is a turnoff due to the low voltage. Below 3.0v, the light wont function.

 

[john61ct]

No one should ever let their LFP drop below 3.0Vpc anyway

An adjustable LVC would be ideal so you could calibrate it to land on a specific DoD% depending on the discharge rate

but otherwise if a fixed cutoff is required, 3.05Vpc would be the lowest I would allow anyway.

LTO is not an option here in 1S configuration, but FYI that is the **only** LI chemistry that is not rendered instant scrap by being allowed to discharge too close to zero.

 

[john61ct]

The Sanyo Pannys from Japan are excellent.

You need to be more specific, each model is more or less suitable for different use cases

while some are eclipsed by other makers' cells.

______
The GAs are no longer recommended, as Pajda has repeatedly stated from years of precisely structured comparative testing.

Also confirmed by many other technically proficient users in the threads I linked to in post #7. GA may shows great performance in initial capacity / power discharge / internal resistance tests when brand new, but it wears very fast in use, showing drastic drop-offs in all three of those factors along with concomitant early/fast waste heat production.

Even avoiding the extreme voltage "shoulders" 4.10Vpc to 3.2Vpc (80% capacity utilisation) does not help compared with its competitors, especially the most superior models I listed above, e.g. LG MJ1 or M36

even when the GA's are full -cycled down to 3.05Vpc, close to 10% of their capacity every time

Also SONY VC7 and even Samsung 35E are dramatically better at maintaining their excellent performance over longer lifetimes.

Note I am **not at all** saying GA isn't good, if genuine new Grade A are selling cheap grab 'em as fantastic **value**, they are better than 97% of what's on the market,

but the OP's use case is clearly looking for top-notch performance, cost is not a priority and GA should therefore not be considered.

Just in case that was the model you meant by "Sanyo Pannys from Japan"

 

[Climb14er]

^^^
I usually have stayed away from... what's the best, this or that, since joining here in 2003, as opinions... differ. The GA Sanyo Pannys from Japan have consistently provided excellent results for me and many others. The Sonys, look 'em up, are very good these days as well.

 

[john61ct]

Exactly my point, many cells will meet a given use case's needs

certainly not trying to plug any as being "best", just pointing out the GA is not in the top tier anymore

At some point cost and availability need to also be put into the picture, and often "good enough" is just that

 

[N/Apower]

Exactly my point, many cells will meet a given use case's needs

certainly not trying to plug any as being "best", just pointing out the GA is not in the top tier anymore

At some point cost and availability need to also be put into the picture, and often "good enough" is just that

100% agreed, but it is an 18650 battery we are talking about. Within reason, price isn't a concern for 3-4 items. The reason I am not all on board with the LFP chemistry is because I see they begin at 3.6V, and discharge down to 2.5V. They only hold about 1200mah. I am presuming this is linear? If so, I could only get 600mah out of this fuel source, and when you're pulling 8A off of it, that doesn't go very far at all. Certainly not as far as a 3500MAH battery with maybe 80-90% accessible to your application initial, no-matter how beat up and how badly it is used, I would think, even compared to the new "600mah" available fuel source.

Please correct me if my maths are terribly off or I am incorrect.

 

[N/Apower]

No one should ever let their LFP drop below 3.0Vpc anyway

An adjustable LVC would be ideal so you could calibrate it to land on a specific DoD% depending on the discharge rate

but otherwise if a fixed cutoff is required, 3.05Vpc would be the lowest I would allow anyway.

LTO is not an option here in 1S configuration, but FYI that is the **only** LI chemistry that is not rendered instant scrap by being allowed to discharge too close to zero.

I had a question about that. This is the testing I've done so far, and if you require a summary of it:

Old laptop pack, 15 years or so, heavily used, sat un-used for almost 10 years, then I tore it open and began using the cells and they are excellent. Good as new.

 

[N/Apower]

Quick Question, where is the LG Chem MJ1 manufactured? I thought Korea only, but on batteryjunction, it says "CN". Is there 2 factories? How can I tell which battery I have?

 

[john61ct]

they are excellent. Good as new

By what objective measurement criteria?

Or do you mean just subjectively, as far as you can tell, just fine, good enough?

If the latter, and you are happy, then likely just about any of a dozen models will do just fine for you.

In which case, this thread was literally started just out of curiosity?

 

[john61ct]

With the excellent QA procedures of top notch manufacturers, the location of the factory should not matter.

The exception is that it is more possible that the Chinese **supply chain** is defective, and QA rejects (Grade B or lower) get sold as Grade A, or secondhand as if new, or of course outright counterfeits.

A known-trustworthy seller then becomes just as if not more important than, any other considerations.

Searching for units based on the lowest price almost certainly leads you open to such shenanigans.

 

[N/Apower]

By what objective measurement criteria?

Or do you mean just subjectively, as far as you can tell, just fine, good enough?

If the latter, and you are happy, then likely just about any of a dozen models will do just fine for you.

In which case, this thread was literally started just out of curiosity?

Subjectively, with a bit of objectivity. I calculated run-time based on OEM mah rating of the batteries, and they more or less matched the calculations in my Streamlight HLX handheld 1000lm light. This is after 15 years, countless cycles, and being "run into the ground" where they wouldn't even make the LED glow and registered in the 1's voltage wise...how they have held 4.15-4.16v for 1 year after being fully charged. All 8 of them. They all took within 15 minutes of each other on the charger, as well.

That said...I am buying new batteries...why not buy the best? So yes, thread was curiosity (I am not flying to Mars under battery power), but also objective information sought (I don't want to buy 2nd best).

 

[N/Apower]

With the excellent QA procedures of top notch manufacturers, the location of the factory should not matter.

The exception is that it is more possible that the Chinese **supply chain** is defective, and QA rejects (Grade B or lower) get sold as Grade A, or secondhand as if new, or of course outright counterfeits.

A known-trustworthy seller then becomes just as if not more important than, any other considerations.

Searching for units based on the lowest price almost certainly leads you open to such shenanigans.

I bought from Illumn, and Orbtronic. I did not use price as a matrix, but rather, reviews and site layout. If words were misspelled often and the layout looked "cheap", and reviews were lacking, I avoided it.

I did notice the Sanyo batteries from Japan always reviewed and tested higher capacity, etc than their CN counterparts.

I am very confused, though:
https://www.batteryjunction.com/lg-..._w5KB6zWLp5a92NJVsAo3ZY9Y30XqFvcaAk8zEALw_wcB

This lists country of origin as "CN", but you click the MSDS sheet supplied, and it shows: " LG Chem LimitedTwin TowerYouido-Dong, Youngdeungpo-KuSeoul, Korea "

I presume that is just a corporate HQ? How would I know if my battery came from SK, or CN? I see nothing on it that is an obvious marking of such.