When your battery gets low, you will see the low battery warning dialog on the screen.

当电池低电时，你将在屏幕上看到低电警告窗口。

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While the Pocket has been charged only once in the eight weeks or so that I had been using it, the Kindle gave me a low battery warning after five days.

我的口袋阅读器在使用的大概8周以内只充了一次电，而Kindle在5天后就告诉我电力不足了。

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Small Dimensions, lightweight; Wide frequency range; Operation status LEDs; Low-battery warning; Internal or external power supply; Suitable for filed test.

尺寸小，重量轻，频率范围宽；具有电池电压欠压和工作状态指示；可内，外供电方式；非常适合于现场和无外接电源时的使用；

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The pilots also received a warning that there was a fault in the battery system.

BBC: Top Japan airlines ground Boeing 787s after emergency

Footie fans can breathe a sigh of relief thanks to the state-of-the-art trolley which comes complete with tilting iPad holder and speakers, a front bumper complete with a sensor which lets off a warning beep if you get too close to other shoppers and an onboard battery with self-charging solar panel to ensure the viewing device never runs on empty.

ENGADGET: iPad dock shopping cart keeps footie fans and their other halves happy