Favorite low battery warning...

Badbeams3

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Some flash the light. Some have a red light that come on. The Jetbeam C8 is built into the switch. Lights green from 100% to 50%...blue from 50% down to 10% then turns red. Think this is my favorite concept (I don't own one). Allows you to have a good idea of where you stand without having to do anything. What's your favorite concept?

jetbeam_c8_5.jpg
 
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reppans

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I'm a battery MacGvyer type that prefers the emergency option of being able to run ANY battery with my EDC flashlight. Modern electronic clicky lights with battery meters and Li-ion protection severely limit that capability (and a few I've used don't even work well), so I generally stick to older tech/mechanical clicky lights - at least for when illumination really counts.

Since a quick DMM voltage check is an accurate indicator of remaining capacity on a Li-ion cell, over time, I've developed a pretty good sense of my remaining battery capacity, just based on my usage pattern. For other battery chemistries, I find a quick high>max>high mode switching to be a decent battery meter (running low when you can't see the output difference). And as low lumen junkie, even if I've already lost my upper high and max modes, I'd still have a day or two of adequate illumination ;).
 
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more_vampires

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Agreed, Reppans. My favorite low batt warning is a digital multimeter. Small, thin, lightweight, and cheap. I just don't trust on-board for some reason, plus the one DMM works for ALL your electric gear, not just lights.

Car troubleshooting, see if a wall outlet is hot, a million reasons to own a DMM and zero not to.

Mine is a $10 Rat shack special. Fits great in a shirt pocket. I barely notice it's there.
 

reppans

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Agreed, Reppans. My favorite low batt warning is a digital multimeter. Small, thin, lightweight, and cheap. I just don't trust on-board for some reason, plus the one DMM works for ALL your electric gear, not just lights.

Car troubleshooting, see if a wall outlet is hot, a million reasons to own a DMM and zero not to.

Mine is a $10 Rat shack special. Fits great in a shirt pocket. I barely notice it's there.

Haha M_V, I was actually was being kind by saying "don't work well" - most of the ones that I have actually hinders an otherwise good flashlight (well for me anyways).

Do you know of an easily pocketable DMM, or at least V meter? I've been searching without luck. I'm thinking of MacGyvering my Drok USB V/A meter for that :).
 

more_vampires

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I forget the model and don't currently have it on me since I'm not traveling or labbing right now.

I just grabbed the smallest, flattest one they had at Radio Shack and never looked back. Its thinner than a deck of playing cards and is perfectly shirt-pocketable. I've had it for over 15 years. Great buy. Never much saw the point of a gigantic desk multimeter unless you're playing with super-big or super-small numbers.

I have a 40 year old analog with a needle. I must have it to measure mechanical voltage regulators that I have not upgraded to solid state. They snap open and closed really fast to "regulate," and a digital meter will just roll the numbers. The needle stays steady. The waveform looks horrible on an oscilloscope with a mechanical. Big, chunky, nasty, noisy, square wave.
 

KITROBASKIN

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CPF member mdocod wrote about using the Xtar voltage detector with a stripped USB cord. This is what I keep in my nightpack now. The USB I use is from a charge cord formerly employed to recharge a toy, with a bit of electrical tape on the exposed wire, preventing my fingers/body from altering the reading. It indicates maybe .02V lower than my DMM; because of the load of the readout display (?).

Favorite battery state of charge indicator? My TM26 and TM36 have their built in display (hundredths). Other NiteCore lights have the blinking switch covers (good to the tenth volt). ZL is OK with the four click flashes. For the high-strung lights, one can get a sense what the state-of-charge is, by the amount of heat they generate. When the heat starts tapering off, it is getting towards half depleted; about where I like to stop using a battery. So that is my favorite.
 

more_vampires

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the Xtar voltage detector with a stripped USB cord.

Never knew I needed this until you mentioned it, sir. Must have. Ordering now. Will pair nicely with my Redilast micro lion chrager since Cottonpicker's with the readout is NLA.

Outstanding.
 

more_vampires

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With the outrageous runtimes in moonlight/firefly running NiMH these days, then my usual low battery warning for those is wait until one dims or dies and then charge up my entire EDC. I go months between charges and carry no spare cells EDC. Spare cells in the BOB, no choice.

When there is no real difference between high and medium is a pretty good indicator, too.

I watch my unprotected hotrod lion lights pretty closely with a DMM. No choice, nature of the beast.

I love the 21st century. Still waiting on hoverboard gen 2 and Mr. Fusion, though.
 

Amelia

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I like the "built in" type indicators some lights have. Examples:
Zebralight (4-Clicks), Armytek (Head Twist Pattern, Blinks out voltage), EagleTac MX25L4C (LED Indicator)
 

uofaengr

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Since I stole my DMM back from my father, I've found myself checking voltage in my batteries almost daily depending on my usage for the day. Still relatively new to the rechargeable game so I'm trying to take notice of my voltage readings relative to runtime in that specific light and figuring out when I should recharge.
 

more_vampires

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Still relatively new to the rechargeable game

Welcome to the party, friend. NiMH doesn't really need to be watched like a hawk. It behooves you to learn as much as you can before you get into multi cell lithium ion lights. Everything you need to know is right here. Search, ask questions.

Never mix and match lithium ion cells in a multi cell setup, this is one of the big "gotcha"s.

Good luck! Be safe!
 

markr6

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I use my DMM often, but it is nice to have something in the light instead of emptying cells, especially 3 and 4x18650 lights. I always found the voltage indicator on my EA4 (5 blinks, pause, 1 blink = 5.1v) and PFlex Pro (9 blinks = 3.9v; 11 blinks = 4.1v) to be very accurate.

Not necessarily "low warning" features, but a way to check before it gets there.
 

the.Mtn.Man

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I like HDS lights, so I like how those work. When the battery is too low to sustain the current brightness, the light will blink and then step down to the next lower brightness, and so on until the battery is exhausted. It's graceful, elegant, and never suddenly leaves you in the dark.
 

WalkIntoTheLight

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Agreed, Reppans. My favorite low batt warning is a digital multimeter. Small, thin, lightweight, and cheap. I just don't trust on-board for some reason, plus the one DMM works for ALL your electric gear, not just lights.

Yes, a DMM can be pretty accurate for a cell that has rested for at least a few minutes before testing. The testers integrated into lights never seem to be accurate.

But if I take a cell out to test it on my DMM, I'm going to charge it up whether it's 10% full or 90% full.
 

reppans

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I like the "built in" type indicators some lights have. Examples:

Yes, the hidden voltmeters that you can call up when needed are the way to go. My Armytek Prime Pro has a blinking green light set on a ~6 second timer.. but mine doesn't work - it only turns yellow AFTER the light has already step down (duh). So now I have power consuming, slightly irritating constant flash in my field of view that does nothing :(.

.... Xtar voltage detector with a stripped USB cord.....The USB I use is from a charge cord formerly employed to recharge a toy....

Yes, that's what I was thinking when I mentioned MacGyvering my Drok... great idea to use an old toy for the parts though, thanks. I'm using Cottonpickers charger/V display currently, but the problem with all these LED/USB meters is that they need to clear ~ 3Vs to get any reading. It's not ideal for AA chemistries - you have start linking cells in series introducing other variables. Perhaps I should just cut some of those PowerCheck strips out of Duracell Alkalines.

Never knew I needed this until you mentioned it, sir. Must have. Ordering now. Will pair nicely with my Redilast micro lion chrager since Cottonpicker's with the readout is NLA...

If you haven't already ordered, also consider THIS Drok version. Few $ more, but I think it has a wider voltage range (up to 13V) for auto use, and has a clock to track output mah, for variable currents (like from solar panels).
 
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uofaengr

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Welcome to the party, friend. NiMH doesn't really need to be watched like a hawk. It behooves you to learn as much as you can before you get into multi cell lithium ion lights. Everything you need to know is right here. Search, ask questions.

Never mix and match lithium ion cells in a multi cell setup, this is one of the big "gotcha"s.

Good luck! Be safe!
Thank you. For my AA EDC it's mostly out of curiosity to see about how much voltage it used that day. I do keep a check on my 14500 in my SC52w for the same reasons and to see how fast it uses its juice. Also to test at what levels the flashing voltage indicator changes from 4 to 3 etc. At what voltage do you typically recharge your Li-ions?
 

more_vampires

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At what voltage do you typically recharge your Li-ions?

As a poster previously said, if I take it out to check it then I'm probably going to top it up unless it's showing 3.8v or more. 4.2v is normal hot from the charger. I feel taking it down past 2.9v isn't good for battery lifespan and I would have topped it back up by then anyway. Lion lights I carry and use get checked weekly, unless I've been using it a bit. Then, I just check it after a session.

I do not charge them unattended. I like to feel the jacket to make sure it isn't overly hot. Too hot could mean the charger missed termination and it's going for deep fry of the battery. I never leave charged batteries on a charger.

Playing with the meter and comparing it to what you are using is a great way to get a feel for what's left in the battery without bothering to check. If it's been so long you forgot, time to check if it's lithium ion.

If I haven't used or checked a multicell lithium light in a long time, I do not turn it on until I have checked in case one of the cells has croaked. I'm paranoid, but I hand load firearm cartridges and have both eyes and all my fingers. I like keeping it that way. They're nice.

Anyway, single cell lights bypass much of this fiddling about and are far, far less a cause for concern.

If my usage is very light, then I go months without actually charging. Most of my EDC is low self-discharge single-cell Eneloop NiMH for low maintenance and concern. You don't have to worry about that setup at all.

If you haven't already ordered, also consider THIS Drok version. Few $ more, but I think it has a wider voltage range (up to 13V) for auto use, and has a clock to track output mah, for variable currents (like from solar panels).

Caught it just in time, thanks! That's even more awesome! Gotta have it. I'd have just ordered it as well, anyway. :)
 
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