When do you replace your battery

[Albinoni]

When using an LED torch and using either NiMH rechargeables or Alkalines when do you replace your batteries?

1. When half way
2. When fully 100% flat
3. When LED is slightly dim.

 

[jugg2]

With primaries, I usually replace them at the first sign of dimming. I take those batteries, and run them in a single cell low power light.

 

[Oddjob]

The good thing about todays rechargeable batteries (LiOn and NiMH) is that they do not need to be run down before needing to being recharged. Before I picked up a multimetre, I used to just recharge a battery when I felt I had used the light a lot.
I stopped using primaries because I felt bad about throwing away used cells that still had a fair amount of power in them. I'm not that environmentally conscious but I am trying to be more environmentally friendly. Running rechargeables has also been cheaper for me as well.

 

[Marduke]

I change batteries (either replace, or recharge, depending) In one of four cases (in general):

1) Visible signs of dimming in a regulated light, or other low battery indicator
2) Going to need to use the light a lot in the coming days for some reason (camping, walking at night, working, etc.)
3) If NiMH show below 1.2v in my device, or alkalines fall below 1.1v (risk of leaking is significantly higher if I go further)
4) Device doesn't work anymore (duh, should be #1 I guess)

 

[WDG]

Ditto Oddjob's comments. Emergency reserve is the best reason I can think of to not use a light to anywhere near exhaustion in normal use. I change the cell in my carry light once a week, using about 1/4 of the cell's capacity through the week, so that leaves me with pretty good emergency reserve. I run a refresh/analyze cycle on my cells every month, so my standby lights get changed then.

 

[WDG]

The thread "Do you swap/rotate batteries" has an additional reason to not run them down, if you're using multi-cell lights. It's too easy to drive one cell into damage territory, as Bort mentioned:

I stopped carrying my L2d after it ate a new Eneloop cell. It was discharged down to .06v ! The other cell measured 1.2v. I just use single cell 123a, or single AA lights now.

Thread has some interesting thoughts on this, and is available here: http://www.candlepowerforums.com/vb/showthread.php?t=185493

 

[VidPro]

when i know its getting empty because of how it acts
when I have great need for it to function for a long time
when i have more time to deal with it
after some set runtime hours that i have a Guess, its about at 1/4 full.
(2 late night walks at med, or 6 at low, that kind of thing)

 

[AndyTiedye]

I check the batteries in my lights fairly regularly, especially at this time of year.

When last week's storms were bearing down on us, I made sure every battery in every light in the house was fully-charged.
Nice to have working flashlights when the power goes out (which it did for 2 1/2 days).

 

[paulr]

Primaries: replace when the light is significantly dimmed. With 123's this tends to mean the light has dropped out of regulation, so the dimming is really noticable. With alkalines (low powered lights) the dimming is gradual and I often don't notice it for a long while.

Rechargeables: sort of the same, swap out on noticable dimming, or sometimes recharge just for the heck of it if I've been using the light for a while without a recharge.

These days I don't tend to use alkalines in high-powered lights much. PT Surge in my car (very rarely used) but that's about it. In low powered lights they are pretty drained by the time the light gets dim, so I recycle them.

I like my 123 lights very much, but tend to use them a bit sparingly, preferring rechargeables for routine use. I haven't been using RCR123's though, and I think both of my favorite 123 lights could handle them.

 

[GBone]

I have many lights that see "occasional use", these batteries get changed at the first of every year.

As far as my EDC lights go the LED's get changed once they show signs of dimming or if there indicators say its time. Incans get changed once they start to show low yellow light.

Of course if I know I will need lots of light I will set a torch up with freshies!

I use MilkySpits MC2 to drain my old 123's....