Regulated vs unregulated

[ledbetter]

I've read some Malkoff users avoid running their lights below regulated voltage specs. Is this due to unreliable or higher battery drain, poor performance, or other reasons?

I like using M91b's below specified voltage with a single li-ion, and lately been using a variety of M31's or 3v Mdc's with a single aa battery for a simple single mode aa light. Similar in output with a M61LLL, though I have not tested run times.

Part of Malkoff's appeal has been most of their single mode lights have the ability to run on a variety of batteries and at a variety of lumen levels. Has what I've considered a plus in reality a negative??

 

[thermal guy]

Haven't heard anything about people not running their lights below regulated voltage specs.lower output longer runtimes. You won't hurt anything. I asked the man that same questions once.

 

[troutpool]

I do this quite regularly with no problems at all.

 

[Olumin]

I usually recharge the 16340 battery in my MDC when I notice it fell out of regulation because its an unprotected cell & I dont want to run the risk of over discharging it. I see it as a low battery warning.

 

[kerneldrop]

There is no harm to the light. Eventually voltage drops low enough and the driver won't send power to the LED. When you get low enough the voltage rises and falls when under use…that is why output becomes unreliable and the light works then doesn't then does again. That's from the dip in volts and the driver….but still no harm.

The only real harm is when sending more volts to the driver than what the driver is designed to handle.

 

[QMT93]

Is it possible for the tailcap to decrease the output of the regulated head? Or is it only possible for the battery to overwhelm/underwhelm the tailcap?

 

[vicv]

If the tailcap has a resistor in it, like the elzetta two stage tailcap or a surefire one. Then it will lower brightness in low mode

 

[LEDphile]

If the tailcap has a resistor in it, like the elzetta two stage tailcap or a surefire one. Then it will lower brightness in low mode

Although note that the purpose of the resistor is usually to drop the light out of regulation and into direct drive mode, with the LED current set by a combination of the battery voltage and the resistance in the system.

 

[QMT93]

@vicv @LEDphile thank you guys for the explanation!