FireFly3 recharging

I have 2 RCR123's for my FF3. Does everybody kill their batteries before recharge, or just every couple days or so switch batteries and recharge to full? This is my 1st RCR123 light and the battery last longer than I would have thought.

You dont want to kill a lithium battery....it will be dead for good. I just charge mine once a week, that wont hurt them at all.

You should NEVER fully discharge those batteries.

They are protected so it's good to know.

Understood. what I've been doing is running it until I see it dimmer, them switching batteries. Maybe I'll just swap them every 3 - 4 days, no matter what the status is.

I recharge mine once a week and go with that. Did discharge one until the protection curcuit cut the juice in another light. No problems, just put it in the Nano charger and it kicked over and charged.

You don't have to worry about memory and conditioning like you did with your old NiCad cells. NiMHs and Lithium Ions have completely different chemistries that don't have those types of old problems. With these, it's best to keep them charged up, and discharging is not only unnecessary, it can damage the batteries, or worse. Overdischarge on a NiMH or li-ion will reduce capacity/voltage permanently, meaning it can ruin your battery. With a li-ion, overdischarge can cause the battery to get excessivly hot, or even spout flames and explode. That's with unprotected cells. If you're using unprotected cells, once light starts to dim significantly, it's time to pull them. If you got your cells with your Fire~Fly III from DSpeck, you've got protected cells. These have circuitry built in that prevents these potential catastrophic failures caused by overdischarge, reverse polarity, or putting it in the charger backwards. It simply turns the battery off.

Unless you're using your light very often (enough to nearly or fully drain the battery), recharging it every few to several days is fine. Whenever's convenient. That's what I like so much about rechargables; with primaries, I'm always unsure of the state of discharge. I don't time my useage with a stop watch each time I turn it on, so after a a while, I've got no idea how much juice is left. With a rechargable, all I have to do is swap the old one for a fresh one and I'm good.

Tremendo said:

Understood. what I've been doing is running it until I see it dimmer, them switching batteries. Maybe I'll just swap them every 3 - 4 days, no matter what the status is.

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Li-ions have no memory or need to be cycled. If you run them down all the way each time you'll get less and less capacity each time. On average 300 full cycles to 80% original capacity is what you get. If you only discharge them a little each time, say down to 75%, you'll get thousands of shorter cycles out of them.

I always have 2 cells in the charger in addition to what's in my lights, so I am never without fully charged batteries. I swap the batteries pretty routinely - basically after each significant usage of a light and at least once a week in any case. Probably overdoing it but as others indicate, no harm at all done to the batteries.