Consumer Reports: Best extended cell phone batteries

NEW YORK (WABC) -- You're on the road and your phone goes dead. Sound familiar? Nearly half of vacationers say dead phone batteries are a problem, according to a Consumer Reports' survey. For those times when you can't plug in, Consumer Reports checked out some smart new ways to keep your phone alive.

Phone batteries always seem to run out when you need them!

To the rescue smart phone cases with a built in battery. Consumer Reports tested four made for popular phones.

For the iPhone 5 or 5s, testers found the $180 Mophie Space Pack almost doubled battery life. It also adds extra memory.

And for Samsung's Galaxy S4, the $70-dollar uNu Unity case also nearly doubled the phone's battery life.

"It is a little awkward to set up but you never have to do it again. That double battery life is there forever," said Bernie Deitrick.

If you can't find a case that fits your phone, this Samsung Galaxy Portable Battery Pack can charge any phone that uses a USB cable, as long as you remember to power up the pack ahead of time. It costs $100.

And if you can't get to an outlet or don't have electricity, Consumer Reports also tested some gadgets that actually generate power ... like this solar panel with a USB port.

Unfold it in the sun to restore power to your phone. It's the

Goal Zero Nomad 7 for $80.

Also $80, Goal Zero's Lighthouse 250 Lantern.

Besides being a lantern ... and an emergency light ... it has a large internal battery to charge your phone. When that battery's spent, you can use the hand crank to power up your phone.

Consumer Reports also has some tips for conserving battery life when you're far from power. First, try lowering your phone's screen brightness and turn off

auto-updates. Use the GPS sparingly. And when there's no signal, put your phone in airplane mode. That stops it from trying to connect, and turns off Wi-Fi, Bluetooth, and mobile connections.