Walmart has 18650's

[ElectricPlasma]

Do these 18650 16340 etc. really need to be used and drained a bit before recharging to keep the batteries healthy? This is sad to say but I have some decent powered lasers and probably only 2 times iv'e discharged some batteries to mabey 3.2V. I usually just top them off when they hit the 4.0V or a bit less.

The best time to charge them is around 30%-80% range, I wouldn't recommend draining them before charging. This is also why a lot of smartphones will tell you to charge when they reach 20%, this is called the LVC warning, or low voltage cut-off. This occurs to sustain enough power at a low voltage to prevent any permanent damage, it's basically a self-preservation mechanism. And obviously there's no point in charging them if they're at maximum voltage (4.1-4.2 etc), so I'd say if you're cells are below 3.8 volts you're good to give em' a charge.

 

[Pman]

Always test the output with a fully charged battery (yeah, kind of a big duh). Only mention that as it seems there are so many new laser owners that either dont charge them first before using or don't understand that some drivers output to the diode are dependent upon the voltage and it can really make a huge difference when there are 2 cells involved.
One way I can kind of tell how good different cells are is to fully charge them and measure their voltage a week later and see where they have dropped to. Mainly do this with any cells I pull from a laptop pack or something else where they have really been used a lot .

 

[Richie89]

The best time to charge them is around 30%-80% range, I wouldn't recommend draining them before charging. This is also why a lot of smartphones will tell you to charge when they reach 20%, this is called the LVC warning, or low voltage cut-off. This occurs to sustain enough power at a low voltage to prevent any permanent damage, it's basically a self-preservation mechanism. And obviously there's no point in charging them if they're at maximum voltage (4.1-4.2 etc), so I'd say if you're cells are below 3.8 volts you're good to give em' a charge.

You're correct, I have mad this mistake once before by accidentally making one of my thrunite 3400's drop to 2.7v and my pcb shut the battery down and wouldn't even charge my Luv v4 wouldn't even recognize it. So I had to put it in my nitecore MH20 to jumpstart the pcb from the onboard charger. Scared me a little. Thought I just trashed a 16 dollar battery

 

[RedCowboy]

Lithiums are not picky like nickles but the lithiums we want are the IMR/INR formulation, the ones at Walmart are for their garden and walkway lights that have solar rechargers and may be tuned to high mAh and not low resistance high discharge.

When running 5 watt plus diodes it's worth buying good cells, I have tested many into a 1 ohm load and the green and purple Efest sag very little.

My SXD running a NUBM44 at 4.5 amps draws 3.12 amps and as the cells discharge a little more, adding a third cell the draw is only 2 amps but at 12 volts inti the SXD, so if you don't use top shelf cells maybe run 3 cells rather than 2 cells.

These work well.


---------------------I buy mine HERE and HERE ---------------------

 

[Richie89]

Lithiums are not picky like nickles but the lithiums we want are the IMR/INR formulation, the ones at Walmart are for their garden and walkway lights that have solar rechargers and may be tuned to high mAh and not low resistance high discharge.

When running 5 watt plus diodes it's worth buying good cells, I have tested many into a 1 ohm load and the green and purple Efest sag very little.

My SXD running a NUBM44 at 4.5 amps draws 3.12 amps and as the cells discharge a little more, adding a third cell the draw is only 2 amps but at 12 volts inti the SXD, so if you don't use top shelf cells maybe run 3 cells rather than 2 cells.

These work well.


---------------------I buy mine HERE and HERE ---------------------

Efest does make some really good cells. I've got a couple for my Jetbeam WLS4

 

[Amply]

Would it be okay to use these for m140 1.8A driver?