How often to use stored 18650's

ike1985

Enlightened
Joined
Feb 11, 2013
Messages
267
So I now have enough 18650s that some of them may be sitting for months without use. I have 5 sony VTC 5's. I usually deplete and recharge my vtc 5 every 2 weeks, therefore some of these batteries could be sitting for 10 weeks. Should I take them down to 3.6V and store them in the fridge? Should I take them out more frequently and just let them run down on turbo with my tx25c2vn?

Thank You
 

ChrisGarrett

Flashlight Enthusiast
Joined
Feb 2, 2012
Messages
5,725
Location
Miami, Florida
If I'm not going to be using my li-ions, for 3 months/12 weeks, or more, they get discharged down to ~3.7v, placed in plastic cases, then ziplock baggies and then placed in the fridge.

Not saying that that's the best way, but that's how I do it and I have a lot in the fridge, lol.

Chris
 

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
Have a read through this thread:

http://www.candlepowerforums.com/vb...-How-long-can-I-store-Fully-charged-lions-for


If you want your cells to last as long as possible with the minimum degradation, then get them down to storage voltage, pop them in a cool place, and never use them.

Really I think people worry far too much about this sort of thing. I want my cells fully charged and ready to go so that if I grab a light it has as much power available as possible. OK they will be degrading slightly faster than if 'stored', but I am using them for goodness sake.

Surplus cells I do reduce to ~3.7V, and pop into a drawer, but I always have some spares fully charged. By fully charged, I don't mean constantly topped off. A li-ion looses around 5% charge in the first 24 hours after charging, then it settles down, so I suppose in reality I am not keeping 'fully charged' cells, but more like 90-95% charged cells as spares.

I have a TK75 with one extension loaded with 8x18650s. I don't really need to use the TK75 much, so this is effectively sitting as a standby light. If I were to obsess about the cells, I would have to take them all out, discharge them and then have to plan when I want to use the TK75 a day in advance so I can charge up the cells.

Imagine having all these lights and then there is a power cut. Your nicely 'stored' cells are not much use are they?

Another aspect of this obsession is that by discharging the cell, you are using up some of its 'cycle' lifespan, which may in fact cause more degradation than leaving it charged. Especially if you then find yourself having to charge it up again a few days later.

So my advice would be to have the lights you use loaded with charged cells (even if left for a month or two), and use them. Then have enough charged cells ready that you can replace used cells from the lights you are using. If you have loads of spare cells, then I would put the ones not being used into a storage state, but not the ones in use or in lights that are on standby for whenever I need them.
 
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