Best battery? 18650 or 21700

[Gaogier]

Hello

I have a good handful of ultrafire 18650 batteries for my torch, problem is I go through about 6 batteries every 30 minutes. They are really poor.

My torch takes both 18650 batteries and 21700, which should I go for? Can you recommend a battery?

 

[Harry Bloomfield]

I have a good handful of ultrafire 18650 batteries for my torch, problem is I go through about 6 batteries every 30 minutes. They are really poor.

You do know, that they are rechargeable, lithium, don't you?

18650 batteries and 21700, which should I go for?

21700 is a higher capacity battery, than the 18650, so the answer is obvious.

 

[opps]

https://www.reddit.com/r/ebikes/comments/wbnakm/comment/ii8tn66

 

[Gaogier]

You do know, that they are rechargeable, lithium, don't you?

Yeah, they just don’t hold the capacity, I took an old drill battery apart last year which had 18650, 2 out of 3 were completely dead, this battery eventually died too, about 15 hours of use.

21700 is a higher capacity battery, than the 18650, so the answer is obvious.

You would think, but I have a microscope that uses a 21700, and it’s a decent battery, I looked up the price and it was 3 times the cost of a “good” 18650.

Batteries that say they are x capacity doesn’t really have real life usage stats. These companies are flying out batteries and torches claiming 50,000lm but only give 250 for example…

I have learned a lot from the guys who actually test tools, batteries, torches etc

 

[Rodders53]

What torch is this?
Incandescent lamp or LED or fluorescent?
What rating in Watts and Volts (3.6-3.7 being roughly the lithium cell V)?

Old used cells from abused tools and tool chargers won't have the capacity of new ones from the major brands such as, say, Sony, Samsung or Panasonic. Buy from reputable component suppliers like RS components and Farnell where they may have proper data sheets, guarantees and suchlike?