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?

 

[Justin Passing]

Those Ultrafire batteries are the worst you can get, just about. They come Free in things.

If you go to an online Vape shop you will find much better batteries with much higher capacities. Panasonic. Molicel and others.
I measured an ULtrafire, it was only about 450mAh. It was half empty - you could tell by where the centre of gravity was.
I replaced them with 2.5Ah cells, which were £3 or so each. Far far better.
You have to be careful whether you get the ones with the "protection" on the end or not. SOme don't have a "button" end sticking out so won't work, etc.

My stereo microscope ring lights are low enough power for 18650's, but ones for multiple stacked images are high CRI 36V7A things. Mains only and don't look!

 

[^woody^]

If your torch is eating batteries that fast, consider getting a new one which will be more efficient and likely have better performance too.

 

[Harry Bloomfield]

If your torch is eating batteries that fast, consider getting a new one which will be more efficient and likely have better performance too.

Sounds like operator error. The batteries in my torches, last for many years.

 

[^woody^]

Sounds like operator error. The batteries in my torches, last for many years.

Yes. I thought the OP was talking about capacity, not physical longevity, and that he must be using the torches on turbo mode or something if they are not lasting long between charges.

A newer more efficient emitter would help with run times.