Battery issue

[MNBob]

Would you recommend traveling without having the battery pack on a pulsar trail? I have had my battery drain twice on me while my rifle and scope were in my pelican travel case. I have checked multiple times if by closing the case if turns on my scope but it has not? Once was on a long trip of 18 hours and today was a short trip. But both times the scope and case have been in a car where it has been cold for several hours. Could the cold being having an effect on the batteries?

 

[ScottJ]

I'm guessing it's a li-ion battery. The cold temps will really knock them down. My cell phone lasts about 3 or 4 days after a battery charge in warm weather. If it's 5* outside, I can have it full charged, feed hay for an hour with it in my coveralls pocket, and it needs charged again. It will come up a little by just warming the battery, but not a lot.
I use 18650 li-ion cells for my external packs for my Pulsar Apex scope. I keep the batteries inside as much as I can and spare batteries in my pocket to keep them warm if it's not warm weather. I've heard of people using small hand warmers to keep the batteries warm too.