18650s in higher voltages?

[gunfighter]

Does anyone believe we will see 18650s in higher voltages?

I'm new to high-power LEDs, but my LumaPower MRV w/Q5 runs much brighter on two CR123As than it does on my single 18650.

I can't afford to feed it disposable lithium batteries, but it really shines (pun intended) with the higher voltage. It seems my 18650 would work much better if it had a voltage closer to a pair of CR123As.

What am I missing? Should I just use RCR123As instead? I thought these cells work best in single cell applications only.

Any insight would be appreciated.

Thanks

 

[scott.cr]

The voltage of the 18650 is a function of its chemistry, so I doubt we'll be seeing anything over the 3.6V (nom)/4.2V (open) li-ions. However, since LEDs run best at fixed current levels, it is relatively easy to build or buy a constant-current source that will run the LED at spec no matter what the voltage, within design constraints of the constant current driver.

I don't know specifically what the Lumapower uses for a current source, but if it's a resistor, it will definitely run brighter at higher voltages. If the LED is being overdriven, it will take a lot more power to get a little more output, so your higher brightness on *123s won't last very long before output drops below that of, say, a single 18650.

 

[mdocod]

best bet would be a Tiablo A8 instead, circuitry is designed for optimal performance on an 18650, the MRV is not.

 

[gunfighter]

best bet would be a Tiablo A8 instead, circuitry is designed for optimal performance on an 18650, the MRV is not.

Hmm . . . I thought it was optimized for 18650s based on the listed run times;

2 X CR123A - 0:55 to 50%
2 X RCR123A 650mah - 0:25 until cell protection shut off light
1 X 18650 - 3:05 to 50%

What (besides runtime) detemines the optimum battery for a particular light?

 

[richdsu]

The Driving Circuitry ( electronics )---- very important -----providing required constant current to drive up the led emitter. :shakehead

 

[Thujone]

FWIW... I run my MRV on 18650 90% of the time. Only when I am trying to impress do i throw in the 2xRCR123 combo.

 

[Yenster]

Hmm . . . I thought it was optimized for 18650s based on the listed run times;

2 X CR123A - 0:55 to 50%
2 X RCR123A 650mah - 0:25 until cell protection shut off light
1 X 18650 - 3:05 to 50%

What (besides runtime) detemines the optimum battery for a particular light?

The way I see it, the initial brightness would be another factor for an optimum battery. If the 2xRCR123A batteries can achive ~700mA through the LED, but the 1X18650 can only achive ~350, then it seems this circuit is compromising between the two batteries (which I don't like because there really isn't an optimum battery).

I always look for the optimum circuit for a battery, not the other way around. And my preference is the 18650 battery, so I usually look for circuits that will drive the LED optimially for that battery.