headlamp battery tricks...

so, i have a bunch of headlamps that the 'lock' feature doesn't work very well.  these headlamps also seem to have some sort of battery draining 'feature' such that if you leave them unattended for a couple months the batteries magically end up dead.  so, what i have been doing lately to try to combat this is flipping the middle of the three batteries to the opposite direction (ie polarity) to prevent current flow.  then, whenever i need my headlamp i pop it open, change the direction of the battery, and turn it on.

now, my question is - by doing this, are there some sort of second order effects that are going to potentially drain my batteries, or cause them to corrode, or whatever?

Just make sure your partner has a headlamp!

I have done the backwards middle battery trick in the past with my black diamond headlamp due to the on botton being pushed and accidentally turning on in the backpack. Somehow the backwards battery broke part of the battery mount and when the battery was put in facing the right direction, no light. I was able to fix it with extensive finicking with a pocket knife when I got home. It was pretty dicey simuling up the k cracks on Pingora in the dark...

paper between the contacts

I haven't had it out in the mountains yet (hopefully I will as soon as I get back from this job in Atlanta), but so far I love my Princeton Tec headlamp, you have to press the button three times quickly to turn it on. It's the only headlamp that I haven't had to flip batteries or do something stupid to keep from killing them all the time. Good luck. Flipping the middle battery was the best solution that I could come up with for BD headlamps. 

I think you should be fine. Those three AA battery holders usually wire the batteries in series to create 4.5v, and so flipping the polarity of one should just mean the circuit is broken as far as I can think. If the three batteries were in parallel for 1.5v, then flipping one would create a short but you would already know if that was the case.

No damage, but what if you cut a small piece of plastic, for example from those blister packs, and stick it between the flat electrode and battery terminal. Make sure that the plastic piece is long enough to be pulled out easily. This is how some electronic devices with batteries are shipped.

amarius wrote:

No damage, but what if you cut a small piece of plastic, for example from those blister packs, and stick it between the flat electrode and battery terminal. Make sure that the plastic piece is long enough to be pulled out easily. This is how some electronic devices with batteries are shipped.

Or cut a small piece from one of those red Solo beer cups. That plastic is thinner and also can be cut into a little "hook" for cleaning out the USB port on your phone. (BUT, fiinsh you beer first!)

I have been flipping the battery too until last month when it unexpectedly drained my battery on an expedition. First time it's happened, but brand new lithium ion batteries in with the middle one backwards, a week later I flip it and turn it for an alpine start and the battery indicator is already in the red zone then the light is barely usable. 

Also screwed up the battery terminal as mentioned by others above, I was able to fix it with a pocket knife but it was not easy. Black diamond sucks in this respect. 

Pull the batteries out and store them, with the headlamp, in a small ziplock.  If you are flipping the battery around, you have to open it up anyway to use it.

Cor wrote:

Just make sure your partner has a headlamp!

ha ha, that idea didn't work last weekend...

Matt Himmelstein wrote:

so far it seems like it is just the BD headlamp owners that have been using these tricks....

When you flip one of the three batteries, you're changing the voltage from end to end from 4.5V to 1.5V. That won't be enough for the device to function properly, but there could still be some current flow at that level, so you may end up draining batteries anyway. Slipping an insulator between one of the terminals (as a bunch of people suggested) is better, that cuts the circuit completely so they can't drain at all.

ahhh, good point - that could explain why this doesn't always work when i leave the headlamp in my pack for a couple weeks....

Rechargeable batteries!

I never really have to worry about my headlamp being charged, or running out in the middle of something.  If you have extra, then you can always trade out for a fully charged set and recharge the old ones whenever.

Another vote for rechargeable batteries. I got a couple Eneloop AAA's along with AA's and C and D adapteres in a big multipack with a charger for $20 a while back. AAA's for the headlamp and AA's for the lantern. That way I always know I am fully charged for a camping trip or evening walkoff. As for getting turned on in my bag despite the lock feature, I like to put my headlamp in a pocket by itself in my bag where there is less of a chance of something else hitting the button. Other methods are putting it in a shoe if I'm bringing those or some other small, hard container. Honestly I've only had the lock feature overridden by accident once or twice and that was when my headlamp was in the big top pocket of my backpacking pack with a million other small things.

As others have mentioned, a piece of paper to break the circuit works great. You can move it to behind the battery when the headlamp is in use, so it's readily available when you're ready to "lock" the headlamp again.

Headlamp locked:

Headlamp on: