Odd Question, should I stick with primaries?

[belomeclone]

For a dollar a CR123, it would take a while to get past the costs that buying the charger and cells would be. Is it possibly smarter to stick with primaries? One of my lights takes four of them, another two, and a few take only one. It's hard to tell when they are low on juice, and the charger would be nice to top them off when I feel the light is dimmer than normal... but with my upcoming EDC only supporting primaries (and getting super hot when not) I may not need a charger for it, and it's my main light.

Just looking to talk it over with people!

 

[geisto]

Cost savings will depend how much you use your lights. You can check how much juice is left in your primaries with a multimeter. Back in the day I was using SF incans and no multimeter, if I wasn't sure the how much is left in the cells, I would toss them and replace them with new ones.

 

[snakyjake]

I've been experimenting with the same idea. Primaries have more energy, thus last longer than rechargeables. I've decided to measure how long my flashlights will last using primaries. Based on my use of 3 batteries (2 flashlights), I'm going on 6+ months. To do this I typically run my lights on med or low. I use my lights as momentary task lights.

I'm trying not to use lithium-ion in my lights to reduce safety risks. Spending $3 (maybe $6) per year is worth it.

Jake

 

[curtispdx]

When I was primarily using high-powered incandescent lights rechargeable batteries were really the only way to go. Now that I've shifted toward single-cell, variable powered lights I find that using RCRs really isn't necessary.

Regarding not knowing when the primaries are close to being depleted, I think I've solved that problem by carrying two lights. (They're both pretty small so it isn't a big deal.)

 

[snakyjake]

It's hard to tell when they are low on juice, and the charger would be nice to top them off when I feel the light is dimmer than normal.

With lithium-ion I typically don't notice a dimmer than normal, it just shuts off abruptly. But, I only use med/low power, so it's already dim.

Keep in mind that topping off and recharging batteries wears them down. Rechargeables already have lower amp hours than primaries, and recharging them reduces the number of charge cycles remaining. I have only seen runtime tests on new batteries. Would be nice to see runtimes on older batteries with 50+ cycles or 2 years old. A lot of my rechargeable batteries don't seem to last more than 2 years with light usage; both NiMH and Lithium-Ion. I don't think I ever cycled 500 times, but the runtimes have become useless on some of my batteries in other devices.

Jake

 

[Robin24k]

How about using rechargeable LiFePO4 CR123's?

 

[jayflash]

FYI, using a multimeter alone, testing primary cells is only valid by checking "flash amps" or using the 10 amp setting to check the short-circuit current the cell is able to provide. New cells can be over 10 amps and used cells drop continuously lower to only an amp or less. If you have a known load or proper resistor, you can then test the volts across it. ~2.5 volts indicates a healthy cell given a one amp load.

It may well be cheaper for many users to stick with primary cells. I use LiIons due to their more stable output into heavy loads. While their capacity is less, their higher voltage reduces the current needed from them compared to primary cells. Good LiIon cells, properly charged, will last five years or more, often with little drop in capacity. YMMV

 

[belomeclone]

How about using rechargeable LiFePO4 CR123's?

Never heard of them, if they work in it I may go for them.

See, I have a flashlight in my car that I will keep Primaries in. Then I have an awesome light that takes four CR123s or two 18650s. I'd like to replace the lights in that one but it probably isn't needed. It'd be easier to just top it off.

But it' not worth investing 60 dollars just to top it off!

 

[Bigmac_79]

Whether the cost is worth it really depends on how often you use your lights, especially on outputs. If you find yourself not needing to replace your batteries often, then lions probably aren't necessary. If you like to use your lights often, the cost of CR123 primaries will add up really fast. I know in my area, a pack of 2xCR123 primaries is $12-$15 (though I know you can get them for cheaper by buying in bulk online). I'd say if you've got a light that takes 4xCR123, and you like using it, it's probably going to pay off before long to get lions.