Does CDR even matter for LED flashlights?

Batteries and Chargers Rechargeable Batteries
1

I am new to the flashlight community but I have some basic knowledge of batteries.

Anyway I joined r/flashlight on Reddit recently and saw there this guide for 18650 batteries https://techmoment.net/best-18650-battery/ I see it as more of a guide for lithium ion batteries in general than 18650s guide.

The author wrote a lot of the CDR importance but I don't really see it mentioned a lot in the flashlight forums and on reddit.

Is my understanding correct that you shouldn't even pay attention to it?

Or is there like a limit? Threshold for how many lumens the flashlight can output before you have to start taking the CDR into the account?

I wouldn't want to buy a low amp rated battery if I won't be able to use it in stronger flashlights I may be buying in the future.

So to stay on the safe side.. What is the minimum CDR rating for a lithium ion battery that can be used in multiple strength flashlights? What is the safe rating that doesn't go overboard like 30A thats probably too much. Is 10A enough?

Thanks everyone and sorry if this is a noob question..

2

Discharge rate is meaningless really because it’s not a technical property but a marketing one. We’ve frequently seen multiple cell rewrapping companies rating the same cells differently. As well as some companies grossly over-specifying the rate.

The value that matters is internal resistance. This is what really determines the maximum discharge current and what reputable companies take as a base for their CDR ratings.

Please note that this has a significance for flashlights but not a huge one.
In unregulated drivers (which you can see frequently) a lower resistance cell will push higher currents.
High power lights shouldn’t be used with high resistance cells as they may over-discharge them.
Lower resistance cells are said to work better in the cold.

I think that’s about it.

3

Hi Agro,

Thanks so much for your input. That gives a whole new perspective to it!

Sounds like i need some reading on internal resistance! It sounds like a really important battery trait.

4

Also worth noting there is a trade off between low resistance and high capacity, so for a flashlight not requiring high current you can by lower current higher capacity batteries for better runtime.

5

Yeah. I also believe that the battery should last longer when it comes to its life cycle? If I am not wrong.. I think I read somewhere that a high CDR battery or the way you say it low resistance? That kind of batteries don't last as long as the low CDR batteries.. Am I correct?