Well I've got lots to say about those 3.0v rechargables... They just about
the worse thing you can get.
1) Firstly they are 3.2v or 3.3v underload. Sometimes up to 4.0V without load.
What does this mean? They are not true 3.0v replacement and they CAN
blow your 3.0v lithium applications - such as a camera. However it won't
blow in a Fenix light. However, depending on the Vf (forward voltage) of
your LED (varies from LED to LED), a low Vf will make you lose the low
level - it will be between low and medium. The drive level for low is about
20-30ma so the Vf for that current is very low, sometimes below 3.0v.
2) Those 3.0v cells are horrible in terms of efficiency. They use an LDO
regulator which essentially is a variable resistor. Actually in some cases
the LDO circuit puts out MORE HEAT than the LED. What a waste.
Just like a resistor, the extra V is eaten up in the form of heat and with a
resistor, ALL the energy is lost in heat versus the LED, puts out part light
and part heat.
3) The capacity of those 3.0v cells are typically even less - sometimes ONE
HALF of a rcr123 4.2v cell. (by the way 3.6v, 3.7v cells all start at 4.2v).
This is due to extra space needed for the circuitry.
I highly do not recommend them. Those of you have used them, I'm sure
you can report the abysmal runtimes. There is a reason I don't carry them
in my store
Rcr123a on the other hand will work ok intermittently. In fact you'll get
a longer regulated runtime on high/max than a primary. You shouldn't run
it continuously unless it's properly cooled (i.e. kept in your hand or on
a bike handle where wind is constantly flowing over it - general rule of
thumb is if it's too hot to keep in your hand, turn it off. And never leave
lights on in your pocket, even with primaries and at low levels.
)
