It shows me an exclamation mark when I'm charging my batteries I am using Samsung green, now blue ones. It goes away, then comes back. Charging both usb computer and USB wall adapter.
i've heard the batteries aren't charged at the same level, and it goes away. i have no idea how accurate this info is. i just read it someplace, can't remember where.
This is a indicator alerting you that the batteries are at different voltages for whatever reason
If you have new batteries allow them to fully charge and this will go away
If it continuously happens.. Change your batteries immediately as you're risking a thermal loop and potentially endangering yourself and others.
As I stated above it indicates a difference in battery voltage, therefore if you have new batteries simply fully charge them. If done in your kangertech device it will take forever but allow them to charge completely. 6 - 8 hours would suffice.