Quoted: NiMH have a HORRID self discharge rate once fairly well used.  Id look to package your invention with some form of new hybrid stlye rechargables like Eneloops or Hybrios so when users pull out the EOtech out of the safe it wont be dead.  Your EOtech would have still been working had those been installed at the patent attys office.

At this rate of charge, there isn't a problem with whatever battery chemistry you want to use. As long as they are in this voltage range, and are rechargeable, you can pick whatever you want.

Quoted: What are you using to prevent over-charge?  Some type of regulator built into the existing cuircut maybe. and what about "reverse" flow into the panel? that would then discharge you batteries...

Those things are included in the design.

Quoted: Does the Zeiss's Z-Point not constitute prior art? Last time I spoke with a patent attorney he explained that the average patent litigation trial was $62,000.  That's just to get to the point of a judge telling the other guy to knock it off. The attorney told me he'd love to take my money but it would be better spent on production. Best advice I've ever followed.

This is an add-on modification.
I'm not making electronic sights.

Perhaps I should make it more clear so everyone knows.
I am now offering to provide this modification to people's existing Eotech AA model sights.
I'm not making brand new sights with this feature.
I don't have the money to buy new Eotechs and mod them.
If you want this on your sight, I can mod your sight for you at $100 plus shipping.

I don't think that this package will ever be available on a new sight from the factory unless Eotech buys this concept from me, or does something similar of their own.
That is not in my plans unless Eotech contacts me to buy the design.
So, if you want this, now is the time to speak up and send in your Eotech AA model, because I'm putting together a list to buy the parts for the guys who've already contacted me.

Just IM me, or email me about it, and I'll provide the information you need for sending in your sight to me.

Quoted: I would think this moddification  would void any warranty that EOTech would do on one of there sights...?

Don't know. I guess that would be up to Eotech.

No invasive internal modifications however. I only go in as far as the battery terminals.

Quoted: Quoted: Quoted: NiMH have a HORRID self discharge rate once fairly well used.  Id look to package your invention with some form of new hybrid stlye rechargables like Eneloops or Hybrios so when users pull out the EOtech out of the safe it wont be dead.  Your EOtech would have still been working had those been installed at the patent attys office. At this rate of charge, there isn't a problem with whatever battery chemistry you want to use. As long as they are in this voltage range, and are rechargeable, you can pick whatever you want. I am impressed with your work, and I did have a few questions in my mind from your original post. 1. The battery selection is fairly good, but I was wondering if you could use the EOTech in your battery mode, yet be able to revert to the standard factory set-up, like an emergency solar malfunction? That adds big-time versatility. 2. For the GG&G EOTech covers, will you in the future possibly to be looking at making another patent, or maybe someone from here will. I noticed that you stated you use mylar in your techniques. Could it be possible to run another solar dual bank of cells (in picture) www.50magnum.com/solar.jpgon the front of 552 looking model so I could do a direct wire up to my SureFire lights and or laser? Just kidding now, but maybe not in the near future 3. If it is snowing real hard and your in a fire fight, will the solar cells need to be clear for a long/short time? Keep us posted, we might be looking for some of your cool stuff.

Yes to all of the above.

There is no real concern with "emergency solar malfunction" because the unit runs off the batteries, and the solar system just keeps them charged while the weapon is in use in daylight. Even if the solar system totally failed, the sight will function just well as it would have if no solar system had been added to it.
In other words, all you get is additional benefits. No function is taken away with this system. There is no failure of the sight operation if the solar system was to malfunction. It's just that no more charging would take place.

For reverting to batteries that you don't want to charge, you could simply put a piece of duck tape or something like that over the panel, and no charging will take place until you remove the tape. The circuit is reverse-current discharge protected, so no battery draining will happen thru the circuit when it is covered over.

Regarding the models using R123 type batteries or possibly others, I'd have to redesign the package to suit that, and I haven't done that yet.
If the voltage is higher, or has a need for more charge rate, then it may require extra panel area as you showed above.

Regarding snow, it's not a concern. Just wipe off whenever you can.
The Eotech sight will run about 3-4 weeks just on battery power alone.
This system simply tops-off the battery charge when you have the unit outside in the sunlight. With regular use outdoors, it stops the system from going dead.
Typically with the standard Eotech, you'd need to replace batteries within that 3-4 week time period. With this system, you do not.
So, with something like snow, you are not in any danger of losing sight function for weeks anyway, regardless of whether you have the solar charger on there or not.
This solar package is not a main power source for the sight. It is a low-rate battery charger that trickles power into the batteries during daily use, to keep them from running down.

I do recommend that people use a normal plug in charger, whenever needed after longer terms of storage, before going out on a mission, so that the batteries are topped-off when you start. Then this unit will keep the batteries going for as long as you need, provided you give them some sunlight each day.


Flashlights and lasers are high-draw items, and run the batteries out faster than a charger like this could keep up with.
Other solutions are possible for stuff like that, but require quite a bit more surface area for solar panels than what we have on this sight.

Quoted: How reflective are these panels ? Reflective enough to give away a position from the sides,or just enough to be barely noticable ?

The panels are glossy finish.
There are some coated copper terminal strips on each end that I mask-off and paint with flat black to reduce the reflection off that. But I don't do anything over the panel areas that produce charge.

The panels could produce a reflection of light if the angle was just right.
There is a possibility that if they were purposely "scuffed" just right to reduce reflectivity, that it might work and not affect charging rate, but that is beyond the scope of what I've designed here. There is a certain school of thought that a certain diffraction of the light can give fuller charging capability which might overcome the loss of transparency that occurred in the scuffing process.
That is something that is beyond my means to reliably do, with any meaningful or measurable results.

Quoted: Neat Idea. Kudos to you. If I kept a rifle in a vehicle rack or something similar this would be the hot ticket. Unfortunately I keep my rifle cased in the trunk and 90% of the time deploy it at night, so Aimpoint is the logical choice for me. If I was going to run an EOTech, I might do this just for the hell of it. It's better than nothing. I assume that this will void the warranty though?

I have no idea how it might affect any warrantee. They might use it as an excuse to not cover something. Hoever, in reality, this isn't doing anything that could injure the sight, so if they did void the warrantee, it would truly be just an "excuse" to get out of covering something.

Quoted: Quoted: I hope the mil folks or for that matter the EO folks give you a good size check to buy your patent! Victor, If you think that something like this solar charging would be a benefit for items that you sell, please contact me and we can talk about what can be done to suit your needs. I can make something for almost any application that uses rechargeable batteries, and I have enough experience in this to be creative for the special needs of  the application.

Unfortunately using rechargeable batts in most NV gear is a no-no at first glance, (voltage fluctuations, possible rare leaks etc.) but I think your solar powered things are "why didn't I think of that".  As I think about this a bit more though, there may be possibilities for some NV apps.

Glad your patent is in place. I cannot think why EO or any other big players would not seek your invention out. Heck, if you did a study and presentation on how much money the military would save on batts every year by going to a system like this.....  Of course you would always have backup batts., but the govy is ALWAYS looking to save gobs of $$ were they can.  Meet the right procurement person after all your research is done, and you might have a good sale on your hands. Could take a long while though as SLOW things seem to progress.

Vic

Alot of applications for this stuff.

Enjoyed speaking with you on the phone, Victor!

Tom,

Could this be applied to a two meter HT?

Quoted: Tom, Could this be applied to a two meter HT?

Yes, absolutely, and it is common to do so in certain circumstances of remote locations.

The power of the radios, primarily when transmitting, can draw alot of power from the batteries.
When alot of power is drawn down from the batteries, it either takes alot of panel area to charge them back up, or it takes a long time for small panels to charge them up.

So the panels would need to be relatively large.
But yes, it can, and is, being done.

Your amount of charge will be determined by the size of the panels you can bring.

Quoted: Does anyone know if anybody makes rechargable N cells?  I've searched like crazy and have only come up with some 1.2 volt Radio Shack that they don't make anymore.

I came up with these from a quick Google search.
Don't know how good they are, but they're cheap.

www.batteriesinaflash.com/index.php?main_page=product_info&products_id=2657

Quoted: Do you have anything to back up your claims of recharging at twice the rate of useage?  I am sure there are people like me who dont want to drop $100 on some unsubstantiated claims.

Here's what I can tell you.

The Eotech 552 which uses AA batteries is claimed by the mfr to have 1100 hour battery life.
A typical set of AA batteries has about 2000mah storage capacity.
According to my calculator, this means that it uses(on average) 1.8ma during operation. That's 2000ma divided by 1100 hours, to give the per hour rate of usage.

The charge panel that I'm employing on this unit has a charge rate in full sun of 22ma @ 3v, with an open-circuit voltage of 4.1v.
This means that when the batteries are connected, and there is the commensurate voltage drop in the system, that we'll get 22ma at that expected system voltage.
Now, since the batteries are only 1.2v each, and in a series pair, that makes 2.4v total plus some room for charging.
So, since the actual working voltage will be somewhat less than 3v, the current will be somewhat higher, perhaps around 20% higher, or maybe 26ma at times.
So, the charge rate at optimal would be around 14x usage.

However, things are not always optimal, so let's look at some reduced levels of performance.
Let's say that the sight only gets half the battery life that the mfr states.
That would be 550 hours, so you'd have 3.6mah usage.
Then, let's say that my panel doesn't work to full capacity because of some sun shading conditions or other suboptimal conditions, and only gives half the charge it's rated at, so say 11ma on average.
That's still triple the usage.

But, we may have a circumstance where we have an overcast day, and we don't get any real charge that day, so we have to wait until the next day to get charging.
Then we'd have an average of 1.5x usage, for the average charge rate in some pretty adverse conditions.

So, basically, I've designed a system which should do at least an average charging of 2x the usage rate of the sight, even when sub-optimal conditions are present.
You have to do this, because sub-optimal conditions are going to be present often, and also people aren't necessarily going to be out in the sunlight all day, and the sight might only get a few hours or less of sunlight per day, instead of a full day's charge.
Some days it might get no charge, or even several days in a row.
And because of the self-discharge rates of some types of batteries, we could go into a negative condition at certain times, that would require additional charging rate.
And, because nighttime use would give no charging, we'll be in a negative condition during night use.
So, there is a need to have some of that extra charging capacity, to overcome the periods of negative charging(battery run-down).

However, we must understand that this is above and beyond what the sight is already designed to do, which is to operate for 1100 hours on a set of batteries in a continually negative, or constant-discharge, condition with no type of charging going on.
So, if you get out in the sun, and let the charging system top-off the batteries, you've "re-set" the beginning of that 1100 hour time frame again, so it's like you just put in a fresh set of batteries, and you still have that 1100 hours ahead of you again.
So, even if you have 2 weeks using the sight with no charging because of bad weather, the sight is still working on its normal ability to run on a set of batteries. You haven't lost anything, beyond what the unmodified sight would do anyway.
When you get back out in the sun, they begin to charge back up again.
So, you always have your existing battery storage level to fall back on, if conditions for charging do not allow the recharging to occur.

So, I've done what I could to build some leeway into it.
Maybe it might not be perfect. Very few things, if anything, ever are.
It should do the trick in most situations.

If you use batteries which have a low rate of self-discharge, like the Eneloops, then I'd really doubt that you'd ever see a dead set of batteries in the sight that is equipped with my mod, as long as you give it some sun periodically.
If it never gets any sun, then it won't charge.
That's the caveat.

I haven't done it with the N-cells yet, but it should likely work on them too.

However, I've been reading alot of horror stories about the Eotechs with the N-cells having a problem with discharging the batteries thru the internal electronics of the sight, when the unit is turned off. Then the batteries are dead when they go to use the sight next time.
I'm leery about applying my mod to these, because I would surely "be hung with the rap" when the batteries go dead, and not because of anything that I did, but because these N-cell Eotechs commonly have this problem.

I've also heard that rarely this has happened with the AA models too, but it seems to be infrequent.

I can assure everyone that my mod will not have reverse-current discharge thru the panel, because I have a Schottky blocking diode in the circuit, specifically to stop any reverse-current discharge from occuring thru my system.
If there is any battery draining going on, it isn't happening because of anything that I've put on there.

I'd be willing to do this to your N-cell sight, AS LONG AS IT DOESN'T HAVE THIS ISSUE OF DISCHARGING ITSELF.

If the sight is not exhibiting this problem, then I'd be willing to do the mod to it.

I can say that the NiMh batteries do have a fairly rapid self-discharge rate of their own, and would require more regular charging activity than the Eneloops would.
I don't know if there are any Eneloop N-cells at this time, but if there are, those would be the ones to use.

If the sight in the future developed this self-discharging problem, I don't know if Eotech would honor their warrantee with my mod in place on the sight.

I'd have to say that people concerned with keeping their warrantee intact would probably be best to not have this mod installed.
It won't hurt anything, but most companies will use any excuse to avoid paying for a warrantee job.
So, if you fall into the category of warrantee concern, then you'd be best to just keep your sight as it comes from the factory.

Since the N-cells are the same voltage as the AA cells, I see no problem at all with this system recharging them.
They just have a lower storage capacity, so this system would bring them up to full in a shorter time of charging.

As long as the N-cell Eotech sight itself isn't defectively draining the batteries, then this same mod will apply to them.

I just don't want to be modding defective Eotechs, and get the blame for Eotech's problem.

Eneloops and other NiMh batteries can be recharged full-cycle between 500-1000 times.
Shallow cyclcing, which is what we're doing with my system here, extends the number of cycles dramatically, but I don't have exact data on how many more cycles can be accomplished by the shallow cycling. I'd estimate at least twice what the deep-cycling charging number would be.

Regarding cold weather, all batteries are affected to some extent by the cold weather.
A normal Alkaline AA battery will be down to 65% of charge when it is at 32 degrees F.
A NiMh battery will be at 95% of charge at the same temp of 32 degrees F.
At -4 degrees F, the NiMh battery will still have about 50% of its charge, and the Alkaline battery will probably not be working.
Litium batteries are similar in temperature performance as NiMh.

This is the nature of batteries, and I can't really do anything about that.
However, charging them during cold weather will help to keep them warmer, and also restore some of the charge lost by the temperature outside.
So, this mod is some help with that too, although the sight's longevity of performance will be affected to some extent by any batteries in the cold weather.

Quoted: Have you tried using a fresnel lense over the solar panel?

I have done this in the past with other systems of larger size.

The Fresnel lens' function is to take a larger area of sunlight, and focus it down onto a smaller panel size, thereby intensifying the sunlight on the panel surface.
This does work to an extent, and has been used in some large-scale solar "farms" in the southwest. You can get about an extra 20% this way.
However, this does increase size(weight/bulk), so it isn't really what I want in this particular application.
Another problem is that the focused heat on the panels which is generated by using the lens, causes more rapid deterioration of the solar panels, reducing their life span.

It's fine for certain applications, but I didn't deem it to be a good application in this particular instance.

I only have a pic from a few years ago, of one of the early prototype units that I did for "proof of concept', which was sent to Crane NSWC for test and evaluation.
This is a pic of one of those. I can make them look better than this, but this is the basic idea.

Glad you like it, Harv.

As I previously stated in the thread, but will re-clarify here, this may be viewed as a mod that they could use to void the warrantee.
If you are worried about the warrantee, then don't do it.
For those with a sight over 2yrs old, it doesn't have any warrantee left anyway.

The panel is unbreakable from impact and there's no glass or brittle parts in it, but it can be harmed if you try hard enough by scuffing it against rocks or abrasive things of that nature. Avoid that.
If you were to rip it apart, the sight will still operate as normal, as if the mod had never been done.

As for what this unit does that a spare battery does not, it allows the unit to work if you don't have a spare battery, by extending the time that it can run, depending on how much sunlight exposure you give it.

I don't recall saying that this is a "range toy", but you might think of it that way if you want. Others think it might be useful to have in certain circumstances.

I'd expect that anything at all could get ruined, and this is no different.
If you treat it badly, it could be harmed.
Just like this broken Aimpoint that I have here on the shelf, that came back from the sandbox.

For those who are severely skeptical, I'd say it goes without saying that they should not utilize this mod.
I've explained the purpose, the method, and the limitations.
Some will see a value in it, and some won't.

My initial foray into this exercise was because I have an Aimpoint Comp ML3 and an Eotech 552. I put the Aimpoint on my "go to" gun, because I had concerns about the Eotech battery life. There were some things that I liked about the Eotech, so I set about trying to address the battery life issue.
I did it, and it works.
For those who see a reason to have it, they can access it if they want to.
It's an option that was previously unavailable to anybody, but now it can be added, if they would so choose to do it.

I don't make any claims that this is the answer to the mysteries of the universe.
All it does is to charge batteries when in the sun, to help them last longer.