Emergency Lights - Regulated or DD? Pls vote...

I am not sure I recall reading about a similar post in earlier threads, but pls do let me know if one has been done already.

In terms of emergency lights, what I mean is a light (LED only in this case) that uses Lithium batts (for long term storage and shelf life) and brightness does not matter, so long as you term it as an emergency light.

What I'd like to know is which do you think is more important for you in that moment of emergency, assuming that you need to use it for a few hours at a go, a Regulated light that runs at a certain brightness steadily until the battery(s) can handle no more and drops it right into 'moon mode', or Direct Drive that gives you light that keeps dropping steadily in output over time?

Please state your preference and reason(s) for your choice. This is just a poll to see everyone's preference, there is no right or wrong, and I sure hope this doesn't spark off a huge debate over virtues of one over the other.

Thank you for looking and voting! /ubbthreads/images/graemlins/smile.gif

I for one am a regulated fan, more so because I know for sure how much light and how long to expect from an emergency light source before it gets too dim for use, and hence to change batteries if needed (or available).

For a true Emergency light I would go the save route and DD it but not overdriving it hard.
I imagine the DD route is more fail-proof, less parts that break, easier to repair. Others might convince me of something else I bet. /ubbthreads/images/graemlins/grin.gif

Thanks K-T. Good point made about less failure points, esp with parts. DD makes for a simple, straightforward connection, compared to Regulated. 1 more point for me to consider there...

I would go for DD for the same reason as K-T. Can't really think of anything else besides having less points of failure.
I think my Pelican M6 LED would make a good emergency light /ubbthreads/images/graemlins/smile.gif

nexro

IMHO there are a number of issues which need consideration on what type of light would make be best for use in an emergency.
1)Reliability, Reliability & Reliability. This must come before all other considerations and by necessity encompasses things like battery sources, switches,corrosion resistance and the materials that the light is made from.

2)Brightness and long run time are again choices for the individual depending on what type of emergency they envisage the light being used for, but would I imagine be a compromise of long run time v useable light.

3)Battery types:
Lithium offer the best chance of avoiding a flat battery but may not be easily come by in a prolonged emergency.

Regulated v Direct Drive? I would opt for regulated due to the reason others have posted about but concede that potentially this might be a possible weak link in the reliability stakes.

Doug

I would opt for a direct drive in a light that has 3 or more 5mm white leds. Each led would be driven at 30ma or less. Having an array of 4-6 leds would provide a good working flood and each led/resistor would be like a separate flashlight...each is like a separate circuit with the battery and would not be affected by the failure of another led.

I love regulated lights but would not like the aspect of having the light suddenly blank out or become unusably dim because the regulator is out of limits.

I would prefer regulation, because I know the lights I have will perform for years to come and have no reason to suspect the regulation will fail. That and I know exactly how much to expect from a light before I have to replace the battery. I have enough flashlights however that I can take my pick between regulation and direct drive /ubbthreads/images/graemlins/tongue.gif but I'd probably find myself turning to my CMG Ultra G first and foremost because it will give me hours of light on one easy to find AA battery. Of course, you have to take into account what kind of emergency situation we are talking about. Inova X5 would also be on my list, since you mentioned lithium batteries... lithiums have more self regulation so perhaps it's not as necessary.

You might have trouble getting replacement batteries for an emergency light, so the ability to run for a really long time (even at diminished brightness) could be handy in an emergency light. After the initial period of full brightness, DD lights typically run for a very long time before they go completely dark. That is the reason I would choose DD for emergencies. I prefer regulated for daily use, though.

I voted for regulated lights because that's what I use the most. Most of the lights I own are regulated. I have some X5Ts, a Streamlight 4AA 7LED, 2 ElektroLumens Blaster IIIs, but I don't use them. The Blaster IIIs were purchased for their long runtime.

Our 2 cars each have MiniMags with a MadMax+ and a NewBeam with lithium batteries and a G2 plus a SC1. I understand why some would prefer Direct Drive, but I much prefer regulated lights. My thinking is that you need to keep spare batteries either way. If I want long runtimes I pick a light that has a long runtime.

I think in an emergency I'd use both and DD or regulated wouldn't be the deciding feature. For example the Zipka or Yukon HL would get used because they met the need for a headlamp or the ARC4, L6 etc. because they met the need.

If your picking a light that is to be packed away for emergency use, size, reliability, cost, runtime are all factors to be taken into consideration. In theory the DD lights would seem to be better because they are cheaper and have longer runtimes, but I much prefer regulated lights for their constant brightness.

I chose DD for reliablity.

Besides, as long as I'm home or near it...

I have enough lights that without battery change I would have a couple weeks of light!

Regulated long runtime gets my vote. I haven't heard any cases of failure yet, so I'll bank on the very high mean time between failures rate. For me, an everled/3D combo does it. Bright with several night's runtime, so no battery changes/spares needed. Not having your light dim is also a concern in tight situations; you need to be able to remove your light as a variable and get your job done or situation resolved.

Regulated, long runtime, AA, LED.
AA because you can put long life lithiums in it for storage and then use regular alkaline AA during the emergency.
My favorite is the UK 4AA eLED.
Although the DD simplicity is very appealing. You can usually get a simple flashligt to work with paperclips, alumimium foil, etc, if something goes wrong.

Re: Emergency Lights - Regulated or DD? Pls vote..

DD.

You get some feedback as to the state of the batteries. With regulated, you know how much time you have, but if you end up switching it on and off a lot, you can lose track of your remaining runtime.

Re: Emergency Lights - Regulated or DD? Pls vote..

Boy, Stanley, this is a tough one. I may change my mind about it after gaining more experience, but I voted for DD.

Funny thing is - I only have regulated LED lights. My concerns are that with rechargeables, unless you are very certain of their state of charge, they can go poof more suddenly under regulation - I think. I may be wrong on that assumption, though.

I prefer regulated LED's but am thinking that with lithium or alkaline cells the dropoff would be gradual with DD and not let you in the dark all at once. OTOH, DD may not give enough light for as long as you need the higher brightness.

Some have mentioned the reliability of the reg. circuitry. I'm hoping it's on par with the reliability of the LED itself.

This could be a: "it depends" sort of thing. If you definitely need a constant, high level of light, then regulated it is. If you have more than enough to spare, initially, then maybe DD is better.

Re: Emergency Lights - Regulated or DD? Pls vote..

Is regulation circuit immune to strong electromagnetic pulse ? And a LED itself ? Metal housing of same flashlights may provide some shielding, but how good such shielding is ?

Re: Emergency Lights - Regulated or DD? Pls vote..

Don't most regulated lights drop into direct drive after there isn't enough power to run the regulator? If this is so wouldn't they still operate in DD if the regulator failed? I obviously know nothing about electronics, so I'm just asking someone with more knowledge.

Re: Emergency Lights - Regulated or DD? Pls vote..

This has nothing to do with regulation vs. direct drive, but one thing I keep in mind when planning for an emergency is this: After hurricanes or ice storms when the stores are out of supplies, "C" sized batteries are often still available long after other common battery sizes have been sold out. Therefore, if you have at least one flashlight and radio that can take "C" batteries, or adapters for "C" batteries, then this can be an advantage in an emergency.

Has anyone else noticed this also?

Re: Emergency Lights - Regulated or DD? Pls vote..

DD

Don't some regulation circuits require a minimum voltage to 'start-up' the light? I don't want to be throwing away cells with a useable charge still in them.

I voted for regulated lights when I realised that the lights that I've set aside for emergency use are big (C or D cell) unregulated lights. In the car I have a Lightwave 4000 with a runtime of 48 hours. In the house I have a Anglelux 1w with a runtime of 24 hours and a Streamlight TT-3C that has a runtime of 33 hours on 3 leds and 18 hours on 6 leds. If you look at my runtime plots in the reviews forum, you will see that almost all of the lights with runtimes greater than 10 hours are non-regulated.