Help! Hurricane Sandy Will Wreak Destruction! What is the Best LED Flashlight?

[davidhunternyc]

The aforementioned $5 tester is the one I've used for years; I can also use it to get a flashlight's amp draw, measure resistance, check household electrical outlets, etc, something battery testers cannot do. And I could pay many times more for a meter that's slightly more accurate, but would make no difference as far as flashlight applications are concerned.

Thanks. I may just decide to save some money and get the one you use. O.K., so how do I use it? Sorry, I really have no clue.

 

[StarHalo]

To check Li-ions: Black wire in bottom plug (COM, common ground, common for all measurements), red wire center plug (VΩmA, voltage/resistance/low current measurement), set dial to DCV 20 (direct current voltage, 20 volts maximum displayed), turn unit on, red probe positive end of the battery/black probe negative end of the battery. Voltage should be no higher than 4.15 after charging, and cell should not be run lower than 3.6 when in use - if your cell is protected, the protection circuit is only to prevent the cell from draining completely (which would kill it) and prevent too high an amp draw, it does not protect from thermal events/overheating and kicks in much lower than 3.6 volts, usually around 2.8 volts, which is far too low and can damage your cell. Check your cell from time to time and when it's at/near 3.6 volts, go ahead and recharge.

 

[davidhunternyc]

Thanks StarHalo,

When I get a multi-meter I will refer to your directions. Also, as I have said before, I just love candles. I have them burning all of the time. One of the reasons I was drawn to the Glo-Toobs is that light is offered in amber. At home, I have 10 crystal dark amber votives and 100 6hr. tealights. The votives are thick and heavy and I'm sure that this set-up along with the Sunwayman V10R Ti+ with additional AA extender and lots of AA batteries would last me quite a while in a black-out. Other emergencies, like access to clean drinking water, would be far more important. Here is a photo of my amber votive. Fire is dangerous but so is electricity. The difference is that fire is beautiful.

 

[StarHalo]

You'll find your flashlight's light to be rather cold and sterile compared to candlelight, but it can be an order of magnitude brighter than a candle, too.

And you have to be able to see before you can get the water; lights are more important than most people plan for.

 

[PhotonWrangler]

lights are more important than most people plan for.

What StarHalo said. A flashlight is one of those things that you don't need all of the time, but when you suddenly need it, you really need it and almost nothing else will do. Too few people realize this, present company excepted.

 

[bemymonkey]

...the protection circuit... kicks in much lower than 3.6 volts, usually around 2.8 volts, which is far too low and can damage your cell. Check your cell from time to time and when it's at/near 3.6 volts, go ahead and recharge.

You should consider the difference between resting voltage and active voltage during use - if the flashlight is drawing a lot of power, your battery's voltage may drop to 2.8V, but when you measure the resting voltage, it will have recovered to 3.x volts. If protection circuits were to cut off at 3.6V during high-power-draw use, you'd only get a tiny bit of your battery's capacity.

IIRC, most LiCo cells are fine down to 2.8V though (depending on the current), and newer cells like the Panasonic 3400mAh are actually designed to cycle all the way down to 2.5V - older protection PCBs that cut off at 2.8V are actually unable to get all the juice out of these batteries

 

[davidhunternyc]

You should consider the difference between resting voltage and active voltage during use - if the flashlight is drawing a lot of power, your battery's voltage may drop to 2.8V, but when you measure the resting voltage, it will have recovered to 3.x volts. If protection circuits were to cut off at 3.6V during high-power-draw use, you'd only get a tiny bit of your battery's capacity.

IIRC, most LiCo cells are fine down to 2.8V though (depending on the current), and newer cells like the Panasonic 3400mAh are actually designed to cycle all the way down to 2.5V - older protection PCBs that cut off at 2.8V are actually unable to get all the juice out of these batteries

Love you guys, really I do. You have helped be out so much but you guys keep speaking code. I am a newbie to all of this. I only understand plain English.

 

[bemymonkey]

Heheh, basically:

1. Consider a fully-charged battery at 4.2V
2. The cell voltage drops when you turn on the light, say to 3.2V (just as an example)
3. If you leave the light on, the voltage will drop further as the battery drains
4. When you turn off the light, the voltage will "recover" to a higher resting voltage

The protection circuits often cut off at 2.8V - but when you turn the flashlight off, the voltage should recover, so your resting voltage is unlikely to be so deep.

In essence, I'm saying that protection kicking in at 2.8V isn't necessarily bad. There are times (such as low current draw) where that's not the case, but 2.8V isn't always too low

 

[davidhunternyc]

Ahh, bemymonkey, this one I understand a bit more. ; ) Thanks. So basically what you are saying is when the battery gets too low in flashlight, to charge it up in the charger? Ten-Four!

 

[bemymonkey]

Hahaha, not quite. I was just saying that the protection circuits kicking in at 2.8V is likely just fine and dandy for high-power flashlights

And yes, charge your batteries when they're empty

 

[Outdoorsman5]

The EagleTac batteries you got are designed to run down to 2.5v, so it "should" not damage them to run them down that low. Many around here (me included) try not to go below 3.0v. This is said to increase the life of the battery. I have a Li-ion battery that dropped below 2.5v, and was below 2.5v for at least 2 weeks (maybe more.) I charged it up, put an "X" on it so I remembered which one it was, and have been successfully using it for the past year. No signs of damage or loss of capacity. On a side note though, if you ever find a Li-ion with voltage that's been below 2.0v for more than a week then it would be best to throw it out. The cell would most likely have damage, and probably could not be trusted. Hope this helps.

 

[davidhunternyc]

The EagleTac batteries you got are designed to run down to 2.5v, so it "should" not damage them to run them down that low. Many around here (me included) try not to go below 3.0v. This is said to increase the life of the battery. I have a Li-ion battery that dropped below 2.5v, and was below 2.5v for at least 2 weeks (maybe more.) I charged it up, put an "X" on it so I remembered which one it was, and have been successfully using it for the past year. No signs of damage or loss of capacity. On a side note though, if you ever find a Li-ion with voltage that's been below 2.0v for more than a week then it would be best to throw it out. The cell would most likely have damage, and probably could not be trusted. Hope this helps.

Yes, this help a lot. I think I even understand you. "Throw away any Li-ion battery that drops below 2.0v." Got it. Now to get a multi-meter so I can actually measure the voltage of these batteries.

O.K., I just got a Fluke 115 Compact multimeter. Perhaps this is overkill and the $6 multimeter would've worked just as good but you guys kinda scared me talking code and all. (Even the guys at LightJunction admitted how crazy you CPF guys are.) The Fluke 115 was rated highly on Amazon. Now, how in the heck do I use it? When I get all of my stuff, I will try and follow the instructions you gave me above. (I also own a couple of antique electric fans and a Variac so maybe I will be able to learn more about these other things with the Fluke too.)

http://www.amazon.com/dp/B000OCFFMW/?tag=cpf0b6-20

 

[Outdoorsman5]

....but you guys kinda scared me talking code and all. (Even the guys at LightJunction admitted how crazy you CPF guys are.)....

That's hilarious, and they're right. I'll admit that some folks are overly paranoid of the Li-ion rechargeable batteries. Many things have to go wrong for them to catch fire or cause a fuss. Don't worry about them too much, but do follow the advice given on here. All I do is check the voltage of my batteries before & after charging to make sure they are not below 2.5v or especially 2.0v, but I try to charge em before they get below 3.0v when possible. After charging I check to make sure they are not above 4.2v, and that's it. If the battery has been below 2.0v for more than a week then toss it. If the battery gets hot while charging or charges over 4.2v then toss it. I've had Li-ion (AW brand) batteries for 5 years, and have had no hiccups. If your Li-ion battery loses more than 0.1v in 24 hours after charging then it's probably going bad, so keep that in mind.

You are already using Li-ion batteries by the way - in your cell phone, laptop, iPad/iPod, camera, and many other electronics. The difference with a flashlight though is that the Li-ion battery is sealed in a water-tight pipe....which makes them a little more dangerous when things go wrong. But, it is rare for things to go wrong, and the high voltage of a Li-ion battery makes for better lights!!

 

[davidhunternyc]

That's hilarious, and they're right. I'll admit that some folks are overly paranoid of the Li-ion rechargeable batteries. Many things have to go wrong for them to catch fire or cause a fuss. Don't worry about them too much, but do follow the advice given on here. All I do is check the voltage of my batteries before & after charging to make sure they are not below 2.5v or especially 2.0v, but I try to charge em before they get below 3.0v when possible. After charging I check to make sure they are not above 4.2v, and that's it. If the battery has been below 2.0v for more than a week then toss it. If the battery gets hot while charging or charges over 4.2v then toss it. I've had Li-ion (AW brand) batteries for 5 years, and have had no hiccups. If your Li-ion battery loses more than 0.1v in 24 hours after charging then it's probably going bad, so keep that in mind.

Wow, I actually think I understand this! Thanks! : )