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powernoodle said:
Kevin - I'm veering a little off topic here, but a 168S at 3.7v will run a KL4 head in regulation, but a single 3.0v r123 or CR 123 will not?
So many questions - so few brain cells.
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No worries. I find that the lithium rechargeables are a pain in the head too (and other areas, subsequently /ubbthreads/images/graemlins/grin.gif). Someone mentioned to me earlier that the technology has yet to mature, and I wholeheartedly agree.
Probably the reason why is that the L4 demands a minimum voltage for the regulator to be able to fire up at full power, and 3.6 is close enough, whereas when it detects 3.0V, it drops into moon mode. You'll recall that with two normal CR123s starting at 6V, by the time they drop to 3V, that's 1.5V per cell and they are nearly dead. That's the L4's working assumption that when the voltage falls to that extent, it's time to bail out.
Rechargeables however can 'hold' the 3.7V nominal rating over a large part of their discharge cycle, so they don't drop out of regulation.