To add to Skydivers119's comments, I own a 6th generation iPod Touch and the battery life has always been dire, much worse than my previous 2nd generation Touch.
I performed some tests this morning that might enlighten you. They may not be conclusive, but they do indicate the nature of the iPod and how it charges. I used two 6th generation iPod Touch models.
Upon plugging the iPod into a power source the battery charge percentage figure (Apple's in-built one*, not a third-party app) does the following (as an example):
First iPod Touch:
- no external power: 67%
- plug into power: 76%
- unplug after 1 minute: 85%
- 1 minute later (iPod in sleep mode for this time): 77%
Second iPod Touch (first test):
- no external power: depleted, iPod will not power on
- plug into power (& wait for iPod to restart): 18% (it took 66 seconds for the battery app to start)
- unplug after 2 minutes: 18%
- 1 minute later (iPod in sleep mode for this time): 12%
As a further test, I redid the second test, even though that I had only just unplugged it from the first test:
Second iPod, second test
- no external power: 12%
- plug into power & within 2 minutes: 37%
- unplug after 6 minutes (total): 48%
- 1 minute later (iPod in sleep mode for this time): 24% (with red battery indicator)
An important point to learn from this is that the battery percentage indicator should be treated with a great deal of scepticism, especially while the iPod is on charge. It will report a false higher charge during charging. I recommend that:
- if charging from very low or depleted, let the iPod charge fully. The more reliable way to do that seems to be to allow the charge indicator to show 99% for at least 30 minutes as mine rarely shows "fully charged"
- if charging from a higher level (i.e the battery indicator is still green), just remember that even if the percentage indicator states 85% (for example), as soon as you unplug it, the percentage will drop considerably
A possible work-round to your iPods running out of power too quickly (i.e. when you're out) is to either re-charge your iPod from your car's USB outlet (if you have one) or to use a power bank. Power banks are portable battery supplies that have a USB outlet that you can plug the iPod into for charging. A 10,000mAh power bank should be adequate for a day or so. You simply charge them at home and take them with you, ready for use.
* For those who doubt this, the 6th generation iPod Touch does have a built-in battery percentage indicator. It's a widget that can be added to the "pre-home" screen (I don't know it official name, possibly it's the Widget screen):
- swipe to the right to reach the leftmost screen
- tap the Edit button at the bottom of this screen
- on the More Widgets list, tap the Batteries + icon to add the battery percentage indicator to the widgets display
- use the drag bar to reposition the Batteries icon if you wish
- click Done
The Batteries display will also indicate the status of some (but not all) Bluetooth speakers and headphones connected to the iPod.