Tips to extend battery life
I always have a spare fully charged battery with me because the idea of running our of juice when I want to shoot is fear-inducing. However, despite my best efforts I have found myself in situations when I have low battery and no charged spare (mainly due to my own stupidity like forgetting the spare, not charging the spare etc...). If you find yourself in a situation where you are low on battery life, here are some things you can do to reduce your cameras energy expenditure, and increase your shooting time.
Turn off non essential features
In these situations, you need to slim down you camera to its bare bones... I would turn off the flowing as soon as i feared a potential energy crises.
- Wi-fi
- GPS (or reduce intervals)
- LCD - IF you can do this, do it, it is a major energy hog.
- Image preview - most cameras are set to show you a preview of you image right after taking it, turn that off.
- Automatic sensor cleaning - do this ONLY after changing a lens and you fear dust.
Don't chimp
Chimping is inspecting your LCD to see how the image looks... this uses a lot of power, so just go without if you can. If you really do need to check your exposure, use the histogram feature in preference to looking at the image. If you don't know how to use the histogram, read this.
Turn down your LCD brightness
You will sometimes need the LCD, so turn the brightness all the way down, this dramatically reduces its energy requirements.
Don't delete files
Hopefully you have enough storage space on your card and have spares... surely we didn't majorly screw up, did we? :) Deleting files uses energy... so, don't, you can deal with this later, on your computer! :)
Remove the card to transfer files
Don't transfer your images through your camera, remove the cards and use card reads instead. this is not only quicker (generally), but means your camera is not using power to transfer.
Be conservative with continuous focus
For wildlife and action photography, I use AI Servo focus. This is very energy intensive, as I am making my lens continually focus. If i am low on battery, I don't hold down focus for longer than needed (where normally I might ride it a lot more).
Limit your use of stabilization
As for focusing, the same applies for Image Stabilization (IS/VC/VR). You can set this on some lenses only to be used when actually taking the picture. If you have good light and your shutter speed is high enough, you might even consider turning it off altogether (I have done this by accident countless times, and rarely notice).
Don't use your metering until you are ready to shoot
Metering occurs when you half press the shutter. If you leave your camera continuously metering, you are wasting energy.
Turn off your camera between shots
Turn your camera off if you know you won't be shooting. Also turn on AUTO power off an set it to the minimum time....
Keep your batteries warm
Not always applicable, but batteries are less efficient when cold, so keep them warm. If you are in cold conditions, take you battery out of your camera and keep if in a pocket close to your body until you need it.
Always have a spare
Always keep a fully charged spare battery in your bag. You can pick up 3rd party batteries for far less than the branded ones, and even if they are not as good, having one ready in your bag is always a good idea even if you don't plant to need it. As an extra, it is always worth having a spare memory card too. :)
Car charger
I have a cheap USB battery charger that can be plugged into a cars cigarette socket... I keep this in my main camera bag, and is an emergency back up system. Thankfully I have never had to use it in an emergency! It is not as efficient or durable as my mains charger, but for a couple of euros it is worth the investment. It is small; light and can plug into a USB power bank (9V) or car adapter if needed.
The bottom line
- Turn off anything that is not essential, so pretty much everything.
- Be conservative with your shooting, focusing and use of stabilization
- Bring spare batteries/chargers next time... learn from your mistakes, or better yet, never be in this situation in the first place! :)