I was going to start a similar thread. Was hoping I could find some rechargeable 123s a that work well with the it Hunter Mkii
For the MK II, or any of the IR Defense thermals, the UNV remote rechargable battery pack works GREAT. I use one with my 35mm MK II and it gives all night performance. I turn the scope on when I get out of the truck and don't turn it off until the hunt is over. All but eliminates the early and often NUC regimine the IR thermals require when warming up. Worth the $'s and pays for it self anyway. I have mine zip tied to the stock and would be happy to post photos is you would like.
JPK
The problem as I understand it is voltage fluctuations between a fully charged battery and an empty one. Rechargeable batteries typically have a higher voltage when fully charged than a non rechargeable version and when empty have a lower voltage than a non rechargeable.This is one of the subjects that has vexed me from the git go in researching thermal. Best I can tell it's pretty much universally accepted that they are high drain devices requiring much battery power. I've also seen in several places, and been told directly, that rechargeables are not recommended for operating thermals due to a multitude of problems associated with them. Ok.
What is recommended for economical extended run time? A rechargeable battery pack. Yayyy!!
What's in that rechargeable battery pack? Rechargeable batteries!
Huh? What am I missing?
http://ecx.images-amazon.com/images/I/61xzlPQ4uPL._SL1000_.jpg
I still curious why these devices are designed with such minimal on-board battery power. Where does that become an advantage? As stated in another post, that's like having a 5 gallon fuel tank for your truck.
Somebody enlighten me.
The problem as I understand it is voltage fluctuations between a fully charged battery and an empty one. Rechargeable batteries typically have a higher voltage when fully charged than a non rechargeable version and when empty have a lower voltage than a non rechargeable.
Lots of electronics are pretty sensitive even to small voltage changes outside of what they're designed for. For example, and I'm making numbers up for this example: your thermal scope has a voltage input range of 5.3v to 3.2v and 2 standard non rechargable cr123's provide a voltage range of full at 5.2v and empty at 3.4v. Now if you use rechargeables they may start full at 5.6v and finish empty at 3.0v. This may cause an overloaded circuit by being .3v over the max input voltage and cause the magic smoke to escape...
The reason the rechargeable pack works is the circuitry that keeps the output voltage much more steady than individual batteries. As to why they don't just include that circuitry in the scope itself and replace that 5 gallon gas tank with a 45 gallon version.... I'd rather be able to bolt on a larger fuel tank when wanted easily vs HAVING to carry it around at all times. Think smaller scope size.
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There's that!However it's not worth losing my warranty over...
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Good point about the extra power being an option. I'm just curious where the relatively short life of the on board power is useful. That said, when my intended scenario of a spotter/scope situation comes to fruition, in theory I may only be powering the scope up when a potential target is located with the spotter? Which would mebbe result in only needing a short battery life and shifting the priority to less bulk/weight. Not sure how the slight increase in power cycling like that may effect that battery life.
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I think weight and bulk have a lot to do with limiting the battery capacity. If you look at various options on the military side, some of them do have more capacity. I haven't used any of them, so it may be because of higher drain, or to prolong change out interval.
On cycling the scope on and off between target opportunities, a VP from IR Defense told me that for their thermals, depending on the frequency of the cycling, it is very likely that you will get longer battery life just leaving the scope on because start up drain is high. And owning IR thermals, I can tell you that warm up takes a while and the NUC requirements at start up are frequent. Much less frequent once the scope has warmed up.
If you cycle the scope on and off, which I used to do, you will miss a few opportunities!
Brian did some testing on the MK II and he came up with, iirc, 5hr 15min battery life for the MK II set on 30 htz refresh rate (which is plenty adequate) with the two battery configuration, he posted on the "Who is buying..." thread yesterday or Monday. That is pretty good, enough for most night's hunting, at least for me. I have a Patrol that spends most of it's time on a rifle as a scope, set on 30 htz. I use an IR battery extender on that for a two CR123A capacity. Works fine. The battery extender works on the MK II or III as well, and I would guess extends battery life another 2hrs or so, which makes the three battery configuration an all night set up, or very close.
In-the-dark field battery changes on the Patrol are quick and easy, on the MK II they can be a bit of a pita because of tight clearance between the cap and the receiver rail, and that is one reason I use the UNV battery pack for the MK II. [Using the UNV battery pack will not void your warranty.]
JPK
The UNV battery pack contains the electronics required to ensure the voltage stays within spec, so I would NOT run the MK II or Patrol from any other power source except CR123A's.
On the other hand, recharging the battery pack from the truck or any other USB source is a fine plan. I don't know if simultaneously charging the UNV battery pack and using it to power a Patrol, MK II or MK III is "permissible," and I would check with UNV or ******** before planning on it, and definitely before trying it.
No one the hot swap, but there is no reason to hot swap either. The MK II and Patrol maintain their settings when cycled on and off. The UNV pack I have provides enough power for an all nighter, or two hunts of the typical duration of my hunts, so I see little reason to swap between the UNV pack and CR123A's, but you could swap back and forth. Once the IR units are warm, a brief off cycle, brief enough that the unit doesn't cool down significantly, doesn't make a difference.
The IR Defense thermals are manual NUC only, as, imo, any scope should be. [Or at least there needs to be a menu option to turn any auto NUC function off - since auto NUC can occur at the worst time, like when trying to shoot a hog. And since auto NUC ought to be shot off, there is no reason for it.] When an IR Defense unit is first turned on it will prompt you to cover the lens and NUC the unit. MK II's and MK III's now come with Butler Creek caps, and the Patrols need them too, so that NUC can be performed quickly and one handed. The NUC'ing becomes second nature pretty quickly, and I do it automatically from when I turn on the unit until I turn it off. Occasionally I will go too long and find the image degraded enough that I "consciously" NUC to restore the image quality, but most of the time I'll NUC sufficiently often when walking or whatever. ALL thermals need occasional NUC'ing, but it seems the IR units need it more often for the first ten minutes or so after turning them on, the more so when it is cold out. After the IR units warm up the required NUC frequency decreases, but there are a lot of factors that affect the optimal NUC schedule, and that applies to all thermals.
The long and short of it is that I am so accustomed to using a MK II or Patrol that I don't recall a specific NUC schedule at turn on, but maybe four or five over the first five minutes a couple more over the next five, then every so often, depending on temps, temp contrast, etc. I will say that even when I have been remiss and not NUC'd for awhile, the image through the MK II or Patrol has never degraded enough that I couldn't make a quick shot if required.
BTW, I meant to add this to my prior post, the Pulsar HD 19A has a four AA battery pack, which provides about five or six hours of continuous run time on a set of good batteries. It comes with a spare battery pack for quick in-the-field swaps (which is a good thing since swapping batteries into the pack in the field is all but impossible for me, at least without a light and reading glasses.) Pulsar actually recommends rechargeable AA's for the 19A.
JPK