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Question about when to stop using rechargables

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khurrle

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Oksy so I have ordered a bunch of rechargable 16340 and 18650 batteries but I understand that they are not protected cells. I want to make sure that I am using them safely and not running them too far down. Can anyone tell me how to judge when they need to be recharged?

My flashlight will automatically switch to strobe when the cells get low so that works there but how do I tell with a laser?

Thanks
 





What I do is charge a battery initially to 4.2v... after that use it in a laser, and as I'm using it, occasional pop it out to check it... once it falls to ~3.1v time to recharge.

After you do this you will know that let's say ~20 minutes of use of battery A in laser B = depleted battery, so you will be able to estimate when you need to recharge your cells.

Often if I'm unsure and lazy I'll just drop the batteries into my charge to top them off, but that's a lazier and worse approach.

Edit: You need a multimeter obviously:p You can grab one from any electronics store, or online.
 
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I don't use the protected cells as the protection circuit can get in the way on some heave discharges
like trying to feed dual driver set-ups.

I charge my cells up before using them then when ever I use my laser when I'm finished using it I
take the cells out and charge them, not necessary to wait till you think they might need charging.
 
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Flaminpyro said:
I charge my cells up before using them then when ever I use my laser when I'm finished using it I
take the cells out and charge them, not nessary to wait till you think they might need charging.
Click to expand...

I was always under the impression that it's best to at least somewhat discharge the batteries before, charging them again?

I guess the better question is, with these batteries, is there any memory effect, or detriment from not fully discharging, and recharging?
 
There is no memory effect with Lipo cells :)

That was true with NiCad cells, they needed to be discharged
but not the Lipo's they are the bomb :beer:

No deterrent from not fully discharging a Lipo before charging it.
 
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In theory it should, but you're better off just getting a decent multimeter.

Edit... with a couple of leads it would work... in theory, I just don't trust cheap stuff like that.
 
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khurrle said:
would this work for checking the voltage of my batts?

Protable Universal Battery Tester Volt Meter for 9V 1.5V and AA AAA Cell | eBay
Click to expand...

This Battery Tester is only for 1.5 and 9 volt batteries.

If is for use with the batteries that you name in your first post (16340 and
18650 3.7volt) the answer is no, the voltage is different.

If is for use with primary bateries (non rechargeable) of 1.5 volt and 9 volt
and secondary 9 Volt (rechargeable), yes, if this model is reliable.

If is for use with secondary batteries (rechargeable) of 1,2 volt, you may
have erroneous results because the voltage is different, and the tester can
consider as the low power battery.

With a multimeter, especially if it is digital, it is not advisable to check the
batteries olone because they may indicate that a battery can have a proper
voltage or near, and still be in poor condition because it is unable to provide
sufficient current and voltage when is in use in the device, laser or other for example.

The best way to do is to measure the battery voltage while the equipment is
running, when the battery is in load.
 
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You can get an inexpensive voltmeter at your local Harbor Freight. I have on of these

image_11746.jpg

(on sale right now) and it is pretty accurate on DC voltage. I compared the reading to my Fluke and it was within .01
 
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