Questions on Drop in Mods, please help.

This is for single 1.5 volt D-Cell Maglite cut down to use just a Single D-Cell. I know that this is not going to be a bright light.

I was wanting do know what drop in options there is for this.

How far they will draw down the battery? Will any draw below .9 volts?

How bright are the different options?

Where can I get these?

I am aware of the Everled but want to know what my options are before I make the jump.

I am considering having a Mod done rather than a drop in if a more difficult mod offers enough advantage to what is available as a drop in.

The purpose is not for a compact light or a super bright light, but a light for utility use that will run off of loose batteries that I have around the house. I refuse to mix batteries.

Still have those batteries lying around?

Madmax, at the sandwich shoppe, runs down to 0.8volts. Have used it in a custom 1xAA light. Not bright, but still useful. The shoppe also sells something called "micro-converter", running from between 1.2-1.6V, driving an LS at 155mA.

I can make you a ZLT unit within a PR base---kind of a custom made EverLED---with the big Mag reflector, even 200mA battery draw (~70mA to the LS) should be able to handle most day-to-day needs. Higher current is possible up to ~700mA battery draw (~200mA to the LS) depend on what you need it for. ZLT unit will drop out of regulation around 1V but will run down the battery much further in "moon mode". Please PM me if interested.

LED mods As Small As Possible?how do you like to be addressed? Is LED good enough??? Do you have any Ideas on something what would drop out of regulation lower than 1V.

Here is how I want to use it and why I want it.

These lights are going to be home and car based. I always have other bright lights as hand if I need something bright.
The purpose is to have a light that will keep me off of my brighter lights when I do not need or desire the output. It will also be to use batteries that I do not have use for since I will not mix batteries. In the car between what I carry on my person and what is in the car, I will have a dozen lights available to use but most of these are for special purposes. At home, I have even more lights. It is to fill a niche, give me something to do with loose batteries that is practical and to save my other lights batteries until my multi celled lights are really needed.

I intend to never buy batteries for it. I seem to forever be accumulating loose batteries. I know where I can get tubes that allow a 1 for 1 swap of batteries to replace the D cell. I will be able to use D, C, AA, and AAA batteries in these lights. I have found that my MicroIlluminator is bright enough to do most of the duties that I want to do.

I am interested, but if you can suggest something that will allow me to go even deeper into to voltage before dropping out of regulation, I would be even more interested.

Where do these loose batteries come from? well, some of them come from packages of 4 batteries and the device only uses 3 so there is a loose battery. The other source of batteries are when I remove batteries from other items after I am not satified with there performance.

I wonder, is there a correlation between how far a regulator will drain a battery and how bright it is....or are these seperate considerations.

This is not a question for battery life. I realize that an item that uses lots of power will have less battery life.

What prompted the question is that I sometimes see specs where an item that drives a bettery hard and has shorter battery life will pull down a battery to .9 volts and one that pulls less power will give longer battery life still only pulls down to .9 volts.

Any answers appreciated.

Well, if MicroIlluminator does most of the job, a 200mA battery draw "plug" with the big Mag reflector should be just as useful. The ZLT unit will be able to handle most common batteries---1.2V NiCd/NiH, 1.5V ZnMn/Alkaline, 1.65V Li, 3V Li But probably not the 3.7V Li-ion unless some precautions are done within the circuitry that will sacrifice some efficiency.

The cut-off voltage is just a rough number---higher current draw device will run down a bettery faster and the battery can usually "recover" after a little rest; lower current devices don't leave much room for recovery.

The 0.9V limit probably has something to do with the Vf of the base-to-emitter junction of a silicon transistor (used to be 0.7V, could have been lower with modern technologies). So you won't see IC-based converters that works to some extreme voltages like 0.3V. If your main goal is to provide low level lights that will run the battery to the ground, maybe you can consider a Satcure variant. Those units will start just above 0.6V and once started, can run the battery down to something like 0.2V. The down side is the low efficiency (~50%). But if you just use it as a "recycle bin", any additional light from a "semi-dead" battery would be a plus.

Finally about my CPF name---I use LED_ASAP in all my PM's and emails /ubbthreads/images/graemlins/smile.gif

Maybe I want both. Something that will run down to .9 or .7 and another based on Satcure to pull it the rest of the way...so I can throw away batteries without guilt.

LED_ASAP>ok, can you compare what you could build with the everled offering. I understand that the everled offering is a side emitter that will run down to .9. I assume what you build would be using a highdome??? Can you test sometime and see what it will draw down to before dropping out of regulation? Also, if I understand correctly, it does not matter if it is drawing at ~200 or ~700 mA. They still draw the battery down to the same point. Brighter would be better if I can draw down to the same point. I do have too many batteries accumulated and a brighter utility light would help me clean house faster. What would running the LS at spec be. I think I would like to use it to clean up all of my loose AA's first, then move to larger batteries while using the MicroIlluminator to clean up the AAA's for now. I do not have the hosts yet as they are in teh process of being built. Oh, and yes, this is for a useful battery recycler. Oh, and what kind of cost are we looking at?

It does matter for the drain-ability if it pulls 200mA or 700mA, the battery with lower load will end up with less juice when you toss it. This is because the batts voltage sag under load. If for example you have 1.1V on an AA battery when resting, it will probably be pulled below 0.9 when a high load is applied, then to recover some voltage when you turn it off.

This becomes more difficult to contemplate if the cirquit is bootstrapped - then start-up voltage requirement is higher than running voltage requirement.

AilSnail....I got confused. Are you saying if turned on and off once a day, the 200mA will pull lower than the 700mA but if turned on and left on, they drain to the same point??? Or did I miss what you were saying completely.

Mmmm, the two requirements---brightness and "deep drainer" are hard to combine. A brighter light will have to consume more current, which means the battery will poop out sooner and leave more energy in "unusable" state. A "deep drainer", on the other hand, will require lower current---remember the more depleted the batteries are, the lower current they can provide. So if you want to near-completely drain a battery, you will have to use low power loads.

Maybe your idea of having two units will work out---one for the first 95% of the energy, the other for the remaining 5% with a low battery draw and dim light.

ok, sounds good. I have plenty of bright lights. These battery recyclers having a usable amount of light is good enough for this application. It might just take me a long time to eleminate my loose batteries which will be fine. Since the batteries are already a sunk cost, the power for these lights will be free. A bonus is I will be polluting less.

Let us say that voltage at rest is an indicator for how many watt-hours (juice?) is left in the battery.
Say that the cirquit shuts off at less than 1V.
This particular AA battery is 1.1 volts at rest. Immediately when the light turns on, the voltage drops, even for fresh batteries.
For this example, a 200mA load pulls the voltage to just over 1 volt, while a 700mA load pulls the volts rapidly below the 1 volt.

So, for this battery and cirquit, a 700mA load is too much to operate, while the 200mA can still emit.

When a battery is resting after it has been used, its voltage will slowly rise again.

Hope this helps.

Sigurd

Yea I tried to say what LMASAP said.

LED ASAP>
I have a little bit of time since it will be a little bit before I get the shortened maglites. You have sold me on the Idea of the ~200mA circuit. Now I would like to learn more about the Satcure or how ever you spell it. I understand that it can get started at .6 volt. With the Satcure with a good led and a battery with .9 volts, how bright would this be, would it be about the brightness of an Arc-AAA? maybe a little less? maybe a little more?

My impression is Satcure units perform better at low current---a 30mA battery draw unit can already give you enough light to find your way around the house; but a 400mA unit is only half as bright as a 300mA ZLT (and the transistor become super hot in seconds). I would say it's possible to have a 100-150mA battery draw unit driving a LS that gives similar light to an Arc AAA (not as bright as the hot spot, but the overall areal lighting would be similar or better). But if you want any more light, move to a ZLT unit.

At 0.9V, the battery is some 95% depleted. It's better to have them power a low (sub-100mA) unit rather than pushing them for higher brightness.

Satcure units are great for low intensity backup and emmergency light because they can last a long time at low levels, but may not be too suited for your primary bright light source.

The SatCure is good for low power applications. 1 or 2 5mm LEDs. Increasing output current requirements puts a lot of strain on the transistors, as I recently found out. Also, one may require larger inductors. This may result in excessive losses because twice as many turns are required in the flyback transformer as one needs in an inductor of similar inductance, thus resulting in increased resistance in the coil wires.

A well tuned SatCure will probably start off as bright as the standard Arc-AAA. But the Arc-AAA is semi-regulated, whereas the SatCure is purely a booster. So at 0.9V, the Arc may have gone to moon mode, in which case, the SatCure will probably be brighter. But if it hasn't, chances are the Arc will a a fair bit brighter. I've found that my best SatCure circuit will just outlast my Arc-AAA and remain brighter than the my Arc-AAA when it has gone in to moon mode.

YMMV. I have had no experience with the premium Arc-AAA.