I received the optic on May 10 and turned it on.
I've spent about 3,000 rounds and a fair bit of dryfire working with it and so far I've discovered that the year long battery life setting is essentially useless
for my eyes. I highlight my eyes because we all see the world through a bespoke set of hardware that is impacted in radically different ways by age, lifestyle, environment, etc.
Minimum generally useful setting for me indoors is about 5, but that washes out with a Surefire on. So I keep it at a 6 when the gun is on the nightstand because it's still visible, although more difficult to see with a Surefire on and the pistol is a secondary option at that point anyway.
To shoot the gun on a typical range day (bright sun) I need it on max brightness, setting 9.
Leaving the optic on max brightness all the time is not a desirable option because when you go from the bright light of the summer sun to indoors, the dot turns into a giant smear with artifacts spread all over the window. You can see the same artifacts around the edge of an Aimpoint M68 style of optic if you turn it up to max indoors...you see the red halo around the outside of the optic. The difference is that on the ACRO those artifacts can easily be confused for the big smeary dot indoors or conditions of low light when you are presenting the gun to a target.
So, really, management of the optic is going to have to be a part of your routine. I have taken to setting the gun at 8 during the day and dialing it back to 6 when I take the gun off in the evening. That gives me a dot that is likely visible under the most circumstances and saves a bit of battery life.
You also need a battery strategy. Thankfully quality batteries are pretty readily available for the ACRO. Renata batteries can be ordered by the 10 pack for less than 9 bucks from Amazon. I am going to carpet bomb the battery problem by having a 5 pack in my glovebox, a 5 pack in my every day bag, at least 10 in my range bag, and one held in the gun by a grip plug as seen earlier in this thread. I plan to replace the battery about once a month whether it appears to be necessary or not.
There is, in my opinion, an additional concern on the Gen5 Glock pistols...or at least on my Gen5 G17: Heat.
My Gen5 gun heats up quite a bit faster than any other pistol I've used except for the P7 family of pistols from H&K. It also seems to hold on to that heat more readily. ARay gave me a good suggestion to try and quantify it, so I did a little back-to-back shooting with the Gen5 G17 and a Gen4 G34.
Gen5 G17 -
Slide temp: 83.3 degrees F (direct from the holster)
Aimpoint housing temperature: 81.1 F
After 100 rounds (5 yard roundup some bullseye)
Slide Temp: 116.3 F
Aimpoint housing temperature: 92.4 F
After 150 rounds (slightly more rapid bullseye work)
Slide temp: 130.6
Aimpoint housing temperature: 97.8 F
After 3 magazines, rapid fire
Slide temp: 158.9 F
Aimpoint housing temp 110.6 F
Gen4 G34 -
Slide temp: 80.2 F
After 100 rounds (same COF)
Slide temp: 92.2 F
After 150 (same COF)
Slide temp: 98.3 F
After 3 magazines, rapid fire
Slide temp: 114.4 F
Now I wouldn't say this is a statistically valid test because sample of one and I made a general effort at keeping the pace of fire the same but didn't absolutely guarantee it. What is useful from that data, however, is quantifying what I was feeling with actual numbers. The Gen5 G17 is, in fact, getting quite hot. When the slide read 158 degrees that was just below the ejection port...the place I put my trigger finger into register. The muzzle end of the slide was over 170 degrees. I plan to do another hopefully more valid test in the relatively near future where I fire 6 magazines through a Gen3 17 and my Gen5 17 as fast as possible, record the total time, and record the temperatures on the guns before and after at specified points.
I suspect the new finish on the Gen5 guns...an ion-bonded "diamond like coating"...is partially responsible for the heat phenomenon I'm experiencing. There may also be some change in the metallurgy of the gun's components that was made necessary by the finish change. I can't say because I'm not a materials engineer.
Most germane to this discussion, though, is that the heat is working into the housing of the ACRO and elevating the temperature of the optic, too. It gets noticeably warm. The temperature readings I was taking off the optic show that it's getting at or above 100 degrees, at least on my gun.
That is something of a concern regarding battery life because temperature negatively impacts the life of these coin batteries:
http://data.energizer.com/pdfs/lithiumcoin_appman.pdf
As you can see on the graph presented on page 4 of that document, battery life at 40 Celsius (which is 104 degrees F...a temperature that the housing on the Aimpoint is reaching on my gun) is cut by about 40% if the battery operates in that range continuously. That data is for a 2032 battery, but it's probably safe to assume that a CR1225 battery does not have any better performance in that regard than a 2032.
It's hard to say how much heat is actually reaching the battery as the optic is heating up or how long it stays in the zone where it could potentially impact battery output in the ACRO.
My opinion based on what I've observed is that if you notice that the ACRO on your gun is warm to the touch after shooting some rounds through it, factor your shooting volume into your battery change strategy. For me, if I have another range day like I did a couple of weeks ago in the Givens class where I fired about 800 rounds in a single day, I'm going to assume my battery got hot enough to drain some life and I'll replace it a little bit sooner. Or, as cheap as the batteries are, maybe right after that range day and then keep with the same 30 day replacement cycle even with the new battery. I blow about 5 batteries worth of value on a single cup of Starbucks at work so it's not a deal breaker.
If you are routinely shooting enough rounds to put heat into the optic or you are regularly exposing it to situations where the optic's temperature can get above 100 degrees for prolonged periods of time go for more frequent battery replacement than the 30 days I'm trying out.
Hopefully all of that makes sense.
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Originally Posted by backtrail540
