Regulated vs unregulated

ledbetter

Enlightened
Joined
Jul 26, 2016
Messages
891
Location
California Central Coast
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

Flashaholic
Joined
Jan 28, 2007
Messages
10,037
Location
ny
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.
 

kerneldrop

Flashlight Enthusiast
Joined
Apr 24, 2021
Messages
2,333
Location
South
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

Enlightened
Joined
Jun 4, 2019
Messages
479
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?
 

LEDphile

Enlightened
Joined
Mar 8, 2021
Messages
320
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.
 
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