Battery level lights?

How come one can drop a hundred bucks easy on a flashlight-
but not know the remaining battery level?
Is it so hard to have a couple flashing lights to let one know how much battery is left?
What about a clickie tailcap with a couple tiny led lights to show the way?
best,
ethan

This is one of the few lamps I know which informs about the batterylevel.

That is one impressive light. Lots of information. I like that.

Sears has a lot of lights that have battery indicators. They are primitive with a green, yellow and red LED but the Sears lights do the job. I wonder if I can take out the indicator and put into a better light. Or maybe duplicate the indicator.

they do let you know when the batteries are flat - they stop working /ubbthreads/images/graemlins/smile.gif

seriously - i think the KumKang Hid Spotlight (new version) has a battery indicator

One version of the Rayovac Industrial 2D has that and it only costs about $6. The first one I saw was on a plastic MiniMag clone made by Tekna around 1988. They haven't really caught on very much over the years.

It is a neat idea, but they need to be optimized for a certain battery chemistry. They wouldn't work very well if you were using NiMH, for instance.

I had one of those Tekna's but lost it many years ago and have not seen them since.

I would assume that M@glight made them stop manufacturing the clone since it was a "clear violation" of the patented flashlight concept. I still have mine in my trunk, but never really used it.

Sears has a series of lights (Dorcy made, I think) that use a colored led system to show alkaline battery levels remaining.

Several of Garrity's LED lights have a simple colored LED setup for battery level. While they aren't the brightest things around (and have pretty nasty looking beams), I think they're nice power failure lights. Got a little blinking 'finder' led, three brightness levels, and the battery indicator. I think it's decent for what it does.

makar, thanks for the link!!! That was what I was discussing with my friend about when talking about battery level indicator but I was looking at a more sophisticated item. For example, the indicator can be the same for all the lights but is programmable to recognize the light it was fixed on.

Let's say a Surefire M3, the light should have a timer to time the total on/off timing that the user had put through the light so that in the event of the battery's power weakening the user is able to know if the battery juice is drained or is it just weakened due to over-heating and that a rest would bring it back to power. There should also be a sensor to tell if the battery is about to suffer thermal shut-down. The sensor should also know if a LOLA or HOLA is used and make a deduction on the battery lifespan. And many more application should be allowed for the sensor in a later stage.

To add, if using a regulated LED light the sensor should be able to tell how many hours had gone by on high power and how many hours there is left on moderate power. It should also be able to calculate current draw and measure temperature of the light. We are equipped with the technology know-how and I think it is a matter of time somebody came up with something feasible. My only fear is dropping the light with the sensor's LCD screen facing down.

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makar, thanks for the link!!! That was what I was discussing with my friend about when talking about battery level indicator but I was looking at a more sophisticated item. For example, the indicator can be the same for all the lights but is programmable to recognize the light it was fixed on.


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you are welcome. your idea sounds intresting to me.

One of the things I really like about the battery packs on Dell laptops is that they have a small button on the rear and four very tiny LEDs. Even if the laptop is off, or the battery pack is disconnected/removed, you can still press the button to light up the LEDs, each representing 25% of the charge. 4 LEDs means full, 1 LED means time to top up the tank. The gauge is accurate too, because once you turn on the laptop, you can get all the gory details from power management.

The only concern is the size of the electronics required to do this and still remain tiny enough to fit on a flashlight.

There is a so called 'smart battery standard' developed several years back. Among the companys were/are M$, Intel, Benchmarq et al.
The idea is that you have a small IC built into the battery pack which monitors the battery all the time, counts charging and discharging Ah, calculates self discharge dependent from temperature and many many things more. It even tells the charger how to charge the battery, so newer chemistries could be used with older chargers. It is all in one IC with a singlke wire interface. Youc an even read out a serial number, name of the manufacturer and manufacturing date. It also is able to tell how much power the battery is able to deliver savely at the moment, depending on charge, state, temp and so on. It recalibrates itself at any charge/discharge cycle. This is the way to go for larger torches/flashlights.

BTW, I also had one of these 2 AA Tekna lights, but have thrown it away (as many other lights).

And the Hartenberger are top of the range, I know them for some two decades and they had been top from the beginning. And even customer service used to be excellent.

One more: When Molicell hit the market with the first rechargeable lithium cells, these had an almost linear volatge drop from full to empty. So they made the best out of it and added a 'fuel gauge'. The first test device using the cells was a power pack for a 2-way 2m Yaesu radio and some selected hams got it. Their comment was: yes, we got more capacity, low self discharge, cold weather ability and much more, but what we care about was the fuel gauge, nobody wanted to use a standard pack again.....

pjandyho, that would be nice, someting like the miles to emply gage on many higher end cars now days.

I wish some manufacturer is listening out there...

The MR-X has a 3mm LED indicator when the light drops out of regulation and goes into direct drive mode... /ubbthreads/images/graemlins/tongue.gif

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PeLu said:
There is a so called 'smart battery standard' developed several years back. Among the companys were/are M$, Intel, Benchmarq et al.
The idea is that you have a small IC built into the battery pack which monitors the battery all the time, counts charging and discharging Ah, calculates self discharge dependent from temperature and many many things more. It even tells the charger how to charge the battery, so newer chemistries could be used with older chargers. It is all in one IC with a singlke wire interface. Youc an even read out a serial number, name of the manufacturer and manufacturing date. It also is able to tell how much power the battery is able to deliver savely at the moment, depending on charge, state, temp and so on. It recalibrates itself at any charge/discharge cycle. This is the way to go for larger torches/flashlights.


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*looks in Surefire's direction*

A 10X Dominator with this kind of "smart" lithium ion pack.. I'd buy it the moment I could and never look back /ubbthreads/images/graemlins/drool.gif I think a number of other customers would appreciate the reassurance of a truly smart pack with battery gauge too, so they know whether they need to top it off. Besides, the 10X is supposed to be the be-all-end-all light in their handheld range.

It sounds like the ultimate battery pack. I've had indicator lights on my laptops since eight years ago, that was when lithium ion started becoming really popular. Incidentally, with regards to safety, laptops sit on...uhh..laps. And I haven't heard of anything about lithium ion packages undergoing "explosive discharge" and inflicting damage to vital organs yet. Lights are truly wonderful things, but I think thousands more laptops containing lithium ion have shipped as compared to lithium ion lights, and still no casualties yet. It sure does seem that it's safe enough for the general public to use. After all, the amount of bumbling users I work with every day carrying laptops is amazing, and still nobody has managed to kill either themselves or the laptop.

Granted, laptops have proprietary chargers, but I figured that the 10X does too (can't imagine you could charge it in anything other than SF's own docking station).

i have heard of someone burning his genetalia with a laptop that got a bit too warm - it was on charge and in his lap
i cant remember all the details - but im pretty sure it happened

Oh yeah, I remember that one, but it didn't have as much to do with the battery and more to do with the total heat dissipation. Batteries will cut off before they reach that temperature (I believe the cutoff is 40degC, lithium ions don't like being charged at temperatures above that), but processors (CPUs) can easily put out phenomenal amounts of heat ranging from 25-40W.

Still, the moral of the story remains.....if it starts to hurt, STOP /ubbthreads/images/graemlins/hahaha.gif