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Is your 'T300-3' a battery for a Magellan RoadMate device?
Battery Is Low, as a message, means what it says. If it is a rechargeable type of battery, try charging it up for a while, 2 or 3 or 4 hours.
If the battery is low indication still comes up after that, you probably have a defective rechargeable battery. All rechargeable batteries, made with whatever technology for portable electronic devices, fail eventually, to either deliver enough power, or to provide enough voltage. This happens after 1 1/2 years or more of usage, usually.
After that, the rechargeable battery needs replacing. And you do not have to buy such a battery through us, or through Magellan either.
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