I have a project where I need to run an audio amplifier from 12V and my own custom Arduino-like board with an Atmega1284P that has no on board regulator.
I recently found this LiPo battery with a built in charger and a 12V 9V and 5V output:http://www.ebay.com/itm/15000mAh-Portable-Rechargeable-Lithium-Battery-Power-DC-12V-9V-USB-/300882146560?pt=US_Rechargeable_Batteries&hash=item460df93500
I've been using these external buck regulators to supply the 5V but it's tempting to drive the board directly from the usb port on these batteries instead.
Unfortunately, the listed voltage output appears to be quite a bit different from what's actually output:
For this guy at least the battery is putting out 6.03v on the USB port. Slightly higher than the 6V absolute max of the Atmega1284P.
I'm wondering though, if the reading is perhaps high because there is no load on the battery? Do you think it would drop below 6V when driving my board? Is that why it's over 5V, so it doesn't droop below 5V when driving a load?
Or is that something that might happen when driving something directly from a battery but with a regulated battery like this it will stay at 6.03V?