How to choose the best 18650 battery

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I need to purchase 30-50 18650 Li-ion batteries.  There is such an enormous range of specifications for this cell that it is mind boggling. I see specs from 1000 mAh up to 6000 mAh. I find that difficult to believe. I am looking for longevity and quality more than capacity. These will be used in a transmitter sending telemetry data. The transmitter will be active for 4 minutes at a time drawing 1.0 amps. Has any Expert seen a brand comparison done that is not manufacturer sponsored rating several different brands? It would be great to see some impartial ratings. I do not want a cell that is very low for obvious reasons nor do I want to push the limit of capacity and sacrifice longevity. Any suggestions would be welcomed. I prefer to buy this type of item either from Amazon or DigiKey.
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Go with a name brand i.e. Sony, Samsung, LG
Here is an article that covers these in depth and how to avoid a counterfeit  battery
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Might also be worth considering under charging.

Lithium cells age more quickly when fully charged. You might find you get 2 years charging to 100%, and 5 years if you only charge to 85%. It certainly makes sense if you value longevity over capacity.

Some electric vehicles already do this. When you charge a Tesla, it only goes to 85% by default, unless you manually override. Charging to 100% regularly is not recommended.
Dr. KlahnPrincipal Software Engineer

Is there some reason lead-acid won't work in this application?  The characteristics are well known, SLA batteries are available in any size you want, and suitable chargers are available off the shelf.  For remote applications, MPPT chargers and solar panels will take care of recharging without the possibility of a Li-ion explosion or fire.


WOW! What a great article. Everything I need to know.  Thanks so much Experts! Don't know what I would do without you. Regarding not wanting to use SLA batteries: Size is a factor and the client specified that the battery or batteries be ONLY the 18650. I want to choose ONLY the very best I can buy. And the idea of only charging to 85% is a super idea. The firmware is nowhere near being complete so I am guessing that we will implement your suggestion. 15% one way or the other is of little concern. Samsung has never let us down no matter what the product. Many ssd drives in use and never a failure. Thanks again Experts!

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