Tomm Willians

By completely discharging/draining a rechargeable light, do you increase the lifespan. Perhaps not every time it’s used but on occasion?

Barry2 

Old time Ni-Cad batteries would acquire a "memory" if partially discharge all the time. The fix was to discharge and full charge from time to time.

NiMH (nickel metal hydride) and Lithium Ion batteries do not duffer from this memory and do not require a discharge.
All you will achieve is to shorten their lifespan.

Barry

mrv 

Storage temperature - don't keep them in the garage when you're done riding. Unless it's just overnight or something. Most flavors of lithium work best in the same temps people do: 25°C.
If you're going to store them for a long time, a bunch of months or longer, then partially discharge after charging them. Store them like you're coffee beans, in a cool dry place. Not the freezer.

Seems like - I've not measure it or anything - after a few winter rides and deeply discharging my lithium lights, the run time permanently drops off. Could just be the batteries aging. Not sure. I've not been able to discern what flavor of lithium they use in these lights. I see it listed as "lithium polymer" - what the heck is that?!? Must be some kind of catch all name so re-packagers can put whatever chemistry they want under the wrapper. I'll have to ask the battery suppliers I work with one day....

I replaced the cell in one of my 350 Lumen Cygo Lights Metro. I upped the amp-hour rating on the battery. Makes a huge difference in run time. If I can get my Light and Motion apart, I'll do the same.
I also finally - put a dyno-hub on my camper / tourer bike. I'm digging it.

Barry2 

LiPo

Barry

Wiggle

Completely discharged is not recommended.

Suggest charging to 50% or just below and storing somewhere room temperature or a little cooler.

mrv 

wandering off topic…. ‘cause internets
polymer means plastic- basically. well, pretty much.
Looking at Wikipedia and BU, these are Li metal / graphite. Using a gel electrolyte instead of a liquid. Here’s what’s interesting- the articles indicate the operating temp is 140F. So I’m still unsure what’s in them.

Typically the flavors of Li batts are described like the BU article
https://batteryuniversity.com/articl...of-lithium-ion

https://batteryuniversity.com/articl...stance-or-hype

this is fun stuff

Tourist in MSN

You did not say battery type.

I store my Li Ion unused batteries or devices in my fridge, not freezer. A couple times a year I check to see charge level, if quite low I recharge them. I have a couple of Li Ion powerbanks that are identical, but one self drains slowly and the other does not.

NiMH batteries, I also store in the fridge but I do not bother to check them for charge. When I use them, I put them on the charger first to top them off.

Some suggest that battery life for Li Ion is lengthened if you only charge to 80 percent of capacity. I have an app on my phone that buzzes when my charge in the phone battery reaches 80 percent during charging.

Lithium ion batteries that are discharged too low might never come back and some have a protection circuit to make sure that they never come back because they could be a hazard. I have had bulged camera batteries that clearly shows that the battery has a problem. They go to the battery recycle bin. A few months ago I had a real difficult time getting a battery that was bulged out of my DSLR camera.

rm -rf

My Prius has Nickel-Metal Hydride batteries to assist with the gas engine. NMH batteries were terrible in cordless drills, losing capacity after just a few years where they barely worked at all.
But the car never discharges all the way, or fills the battery completely -- perhaps 25% to 80% charge levels? That makes it last for well over 100,000 miles and 10 years or more.

Avoid storing the battery full or empty.

Lithium batteries are recommended to be stored for longer terms at 50% to 75% charge.
My Galaxy S21 has an optional setting that stops charging at 85%. That works great for me.

a1penguin

My EGO battery operated string trimmer manual says that if the battery is unused for 30 days. It's a big block of standard 18650 Li Ion batteries.