LiIon is 4.2 volts. You can't get a protected battery to discharge to that low a voltage! Battery University has good info on prolonging battery life for many different battery chemistries.

How to Prolong Lithium-based Batteries - Battery University

Why, is there something wrong with your light besides the battery?

when Cygolite says that there is a low battery indicator what does it mean? I have yet to figure it out on my HOtshot?

The low battery indicator indicates low to empty battery when the light quits working.

J.

[MENTION=219896]JohnJ80[/MENTION] thanks I was hoping for something a bit more scientific and less abrupt and Dark!

On the Hotshot the box says the light flickers when turning on/off, I didn't see anything on the headlight box about any low battery indicator.

There's one in every bunch. This time it was me, I guess.

J.

[MENTION=219896]JohnJ80[/MENTION] it is okay we all have our moments.. haha

The newest Cygolite Hotshots will flicker when turning on or off to indicate low battery. It might last 30 minutes to an hour on one of the flash modes before it goes dead. I have run my Hotshots dead many times.

The Expilion front light will start to flicker the light inside the power button when the battery gets low. The amount of flicker/flash increases as the battery gets lower, and the light output also reduces. I have run my Expilion 700 low many times, and completely dead a few times.

I have not noticed any apparent loss in battery life on any of the lights yet, and they are now entering their 3rd fall/winter season.

++++++1^^^^^^^^^^^ Good info to apply to my Expilion 850 and Hotshot.

I forgot to follow up. Cygolite said they would charge me $5 or $10 to replace the battery, but instead, they sent me a whole new light, complete in the package with mount and cable and everything, even though I didn't send everything back to them as they had requested. I had lost some of the pieces. Anyway, I consider this to be very good customer service. Cygolite seems like a good company, and it sure doesn't hurt that they make their stuff right here in the US. Imagine that! They make good stuff at good prices and figure out how to do it domestically.

battery life is actually better with the new, higher powered light. I was a little surprised, since it looks nearly identical

Thanks for posting. Good info.

Seemed like a thread in which to insert this. I don't ride at night, so my use for lights to be seen so I use the first blink function, not necessarily to see. I have a Cygolite (Metro) headlight and the Cygolite Hotshot taillight. Use them on every ride regardless of whether it is sunny or overcast. I generally throw them on the charger after each ride, or every other ride. Today, after a one hour ride, decided to just let them go and see how long they last. The headlight completely died at 7 hours, I would give it 6 hours of good visibility and function. The taillight, well it is still on, and its been 8 hours! Just an FYI and I have no connection to the manufacturer.

I don't know about the lower powered (Metro) lights, but my higher powered Expilion light says not to leave it on for more than 10 minutes without it being on a moving bike. Something about the metal casing acting as a heat sink and needing air flow, I think.

On your Metro does it have the daytime flash function? On mine I press and hold the power button when first turning it on, and it switches to a mode where it stays off for a second then flashes 3 bright flashes at full power, then off for a second, then 3 flashes, and so on. I like it because the battery will last me a week or more when I use that mode only, but the flashes are still full brightness.

Hmm, don't know about the initial press and hold first thing. I'll try it when recharged. I did not sense any heat issue when I did the test. It was a steady blinking with on and off time seeming equal. The pattern you describe does sound like it would last longer.

Oh that must be a different flash pattern specific to the Metro.

*edit* I looked at the Cygolite website. On Expilion lights, the DayFlash mode I described above is a "special" mode that is accessed by pressing and holding the power button. On the Metro lights, DayFlash is one of the normal modes that you get to by just going through the modes - it's after the SteadyPulse mode that's meant to be used at night (keeps the light on and pulsates every couple of seconds). If you press and hold the button you get to the one special mode for walking, which is lower than the lowest regular setting.

When you were quoting Looigi I think you misinterpreted what he was actually saying when he said...

He wasn't implying that he was discharging the battery to half it's voltage. He was saying he was discharging the battery to 50% of it's usable capacity...not the same thing as voltage. Capacity is usually expressed in either mAh ( milli-amp-hours ) or just amp hours. Since he was saying that the lamp usually gave him 7 hrs of run time, half that is 3.5 hrs. That doesn't mean the battery is at 2.1 volt after 3.5 hrs. Not the same thing. Normal protection cut-offs ( like you said ) are like 2.8-3volts...so at 50% ( usable ) capacity the voltage might be somewhere near 3.6 volts FWIW.

Anyway, before you start suggesting that he ( or someone else ) read up at Battery University you might want to do some more reading yourself. Not trying to make you look stupid, but since Looigi didn't explain what he meant I felt it needed to be clarified so someone else doesn't assume the same thing.

Li-ion batteries slowly leak away their charge, if they get to zero charge they are very susceptible to damage and complete failure. Charging them up every three months should do the trick.

If I remember right, that's not what happened to me. I didn't let the battery discharge. The battery just lost its ability to hold a charge, and it happened prematurely. But these things happen. Rather than replace the battery, the company replaced the whole light, and with it, I got new mounts, which came in handy. I'm impressed with the quality and service from Cygolite. I also like the fact that they make their stuff here in the US. We have to expect a few defects here and there, and service compensated for that. By the way, welcome to bikeforums.