LED Weapon light: Is battery bounce a concern?

I've been trying to narrow the options for my choice of AR-15 weapon light. I want a P60 sized 2xCR123 system with LED lamp and a forward clickie.

My options seemed endless until I ran across a comment regarding "battery bounce". The claim is that without compression springs at both the tail switch and lamp assembly, the batteries will bounce under recoil and the light will switch on and off.

Anyone experience this? Should I be considering a spring on the back of my LED lamp assembly? What are my options besides the Surefire brand and the cheap DX ones?

Any insight on this topic would be appreciated.

Thanks

I started with a G2 body, Z32 bezel, Z49 tailcap. I installed a DX 11836 lamp, outer spring removed, and it flickered when I hit it, every time. I switched to a Surefire P60L lamp and it works solid - no flickering at all, and it fits with the outer spring on, of course. Outer spring provides continuity for the lamp and I think it was actually lamp bounce that caused flickering in my case.
I put the 11836, outer spring removed, into another G2 and it still flickered when hit. To lessen lamp bounce, I installed a teflon ring on the inside of the head, resting between the glass and the lamp. It leaves a slight gap at the base of the head, but eliminated the flicker when hit.
I hope this info helps you some!

Yes, it helps . . .

So would I be well served with a P60 sized LED drop-in that isolates the batteries from both ends via compression springs?

I see that Malkoff, Lumens Factory, and Dereelight have spring-backed P60 modules. I'm trying to decide if I can get away with a simple spring-loaded system and not pay the big money for one of Surefire's shock-isolated weapons lights. It seems reasonable that the shock-proof nature of LEDs would work better, assuming I can keep battery bounce, and now lamp bounce to a minimum.

Am I missing something important?

Bounce is much more of a condern with multimode lights than with single-mode lights.

LukeA said:

Bounce is much more of a condern with multimode lights than with single-mode lights.

Click to expand...

I understand that with multi-mode lights I'd have the problem of it switching output levels under recoil. Unacceptable . . .

But even with single-mode lights, isn't battery bounce a problem? In other words, isn't it a bad thing to have the battery post separating and then crashing back into the back of the LED circuit board?

I have a P60 drop-in from BugOutGear that has no spring. If my batteries did bounce, it seems they'd be doing damage to either the contact surface on the module, or to the batteries themselves. Or am I concerned about nothing?

I'm now considering Dereelight's CL1H V4 with the 1SM-2 pill. It has a rear spring . . . am I on the right track?

gunfighter said:

Yes, it helps . . .

So would I be well served with a P60 sized LED drop-in that isolates the batteries from both ends via compression springs?...............
I'm trying to decide if I can get away with a simple spring-loaded system and not pay the big money for one of Surefire's shock-isolated weapons lights. It seems reasonable that the shock-proof nature of LEDs would work better, assuming I can keep battery bounce, and now lamp bounce to a minimum.

Click to expand...

The LED's shock proof nature does ease some concern; I still use the shock-isolating bezel because I already had it on there. Alot of us financially challenged shooters have been mounting SF P/G lights without experiencing failures, but part of that reasoning is because the 5.56/.223 AR15 has relatively light recoil. That's the limit to my experience. Calibers that produce heavier recoil may be a whole different story. With NATO loads, I've shot repeatedly for 15 minute sessions with the light on without light failure, so I do have a good amount of confidence in my setup. This is using lamps with inner and outer springs. I've never fired with lamps using inner springs only, or no springs at all.
Good luck!

gunfighter said:

I understand that with multi-mode lights I'd have the problem of it switching output levels under recoil. Unacceptable . . .

But even with single-mode lights, isn't battery bounce a problem? In other words, isn't it a bad thing to have the battery post separating and then crashing back into the back of the LED circuit board?

I have a P60 drop-in from BugOutGear that has no spring. If my batteries did bounce, it seems they'd be doing damage to either the contact surface on the module, or to the batteries themselves. Or am I concerned about nothing?

I'm now considering Dereelight's CL1H V4 with the 1SM-2 pill. It has a rear spring . . . am I on the right track?

Click to expand...

I believe that you're thinking correctly about batteries bashing the lamp with springless lamps. I'm not sure on how well they're built, but I imagine that repeated bashing would eventually cause damage and failure. The lamps with a single inner spring would be better, as long as the outer edge of the lamp remains in constant contact with the inside of the battery tube. If you use a lamp with the outer spring also, the chances are better for uninterrupted continuity. Tactical Night Vision has a 2-spring lamp with advertised 256 lumens if you need that much.

I have plenty of exp on this!

Just stretch out your springs on both ends a bit and make sure you keep the negative path established and you won't have any trouble.

You real issue is from one battery hitting the other and they damage each other more than Led or incan module. A little taping together stops that. It's hardly a concern with primary cells, they are usually out of juice before they get damaged enough to compromise themselves.

That said you're talking about a buffered 223. rifle recoil, just don't need to worry about it.

If you use your set-up and run into flickering issues from it send me a detailed PM and I will help you work it out 100%.
:twothumbs

Sgt. LED said:

I have plenty of exp on this!

Just stretch out your springs on both ends a bit and make sure you keep the negative path established and you won't have any trouble.

You real issue is from one battery hitting the other and they damage each other more than Led or incan module. A little taping together stops that. It's hardly a concern with primary cells, they are usually out of juice before they get damaged enough to compromise themselves.

That said you're talking about a buffered 223. rifle recoil, just don't need to worry about it.

If you use your set-up and run into flickering issues from it send me a detailed PM and I will help you work it out 100%.
:twothumbs

Click to expand...

Thanks for the offer! You just never know . . .

To clarify, are you also advocating a P60 drop-in with dual springs, or would I be well served with just a stretched-out inner spring like the ones on the Malkoff modules?

What are your thoughts about 2xAA lights? To my knowledge, there are none that utilize a spring-loaded LED module. Any issue with the additional weight from AA primaries?

Dual springs are best but not totally needed. Wolf eyes makes one of the better led modules for rifle work. If your head and body tube connection is nice (ie all actual Surefire is a good bet) and tight Malkoff's are excellent as well, especially the F models for indoor work.

Avoid the AA's - you are right about the weight. The length might be a touch ungainly and the light weighty if you are humping it for more than a few miles. The cheap common cells are a nice theory but short shelf life and leaking take their toll. Think about how long the rifle light will sit VS being actually used. Stay with Cr123 primary cells.