Hi, Although this discussion thread ended in May 2016, I, a new member here, can still appreciate and need the experience sharing related to the topic from all posters. Now I come to need your input and help for my own camping trip plan. First I recently acquired a new D3500 for my new hobby. The camera came with two kit lenses: 18-55mm and 70-300mm. I plan for a spring trip for about 10 days to Mohave Desert, Organ Pipe Cactus National Monument, and Joshua Tree National Park. I expect to shoot night star sky, the Milky Way, and some Star trails (and of course some scenic photos). And the last thing I started to consider preparing for the trip is the battery. The camera came with a new EN-EL 14a Li-ion. According to Nikon's doc, the battery is rated 1500 shots per charge. I know in reality it won't last that much considering video, setting, live view, and other activities. So I roughly estimated that it can go 500 shots plus all other usages. Then I thought 500 could not be enough for my trip especially considering there will be many night time, long exposure, and double-file (RAW and JPG) shots. So I bought another Nikon EN-EL14a from AMZ (almost all reviewers state it's genuine, legit) for making up to 1000 for my trip. Now come to my surprise, my use test resulted in a very low score for both batteries (original and new bought). My use test simply goes like this: fully charge the battery; put it in the camera; start using (setting, live view, taking shot... ) without taking out. Both batteries all run for 10 days and down to 1 bar (red). During the 10 days, the bought one made about 75 shots w/o video and the original one made about 95 shots plus one 24s video. Both had night shots. So how do I validate these batteries with Nikon's doc? Do I or my use test miss something? Does this mean I'll at least need 5 batteries to make 500 shots and 10 for 1000 shots during the trip? Even making an equivalent shots calculation: actual shots 100 + 50 for other usages = 150 shots, still way too low (1/10) for 1500 rate. The number just can not be justified. Any thoughts? Appreciate all inputs.
(I have also heard that some cameras may have short circuit inside and that can cause power drain even unused. Can this happen to a new camera?)