Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: how long is battery life on high volume with cord?
Document: Nice bluetooth headphones, very large over the ear fit ~ does not touch my ears at all. A bit heavy on the bass for my liking, but my kids love the bass, so all in all, it is a headphone that is in high use around the home. Battery lasts a really long time... I think over 20 hours use. So far, so good, no problems at all with these. Connection to any device is a breeze.
For such a price so many functions - loving it!What struck me was how easy it is to connect to bluetooth devices compared to other similar devices!Wireless sound quality - 4+SSD card sound quality - 5+Long battery life!Highly recommended!
So I look like princess Leah wearing these at the gym...but its worth it.The battery life is ridiculously long and the sound is great (play around with the eq's)...I have not done the firmware update since the adapter that connects the headphone to your computer is impossible to find.
The sound is exceedingly loud ( I put it up to my ear and adjust volume before putting them on). I have arthritis, pushing the button controls is no problem. Their simple to use, and I'm know Tec geek! The battery life is great, takes about 3 hrs to charge. Charge them when you first get them, for best battery life.
Or that piece of hardware may or may not be just for actually activating and using the aptX? This is also unclear, and frankly, not worth finding out at this point.I am not an audio snob. I want good, well-balanced sound. I want a reasonable level of comfort. Simple controls. Long battery life. Strong Bluetooth connection.
These headphones have worked perfect for what I was looking for. I will mention that I'm not an audiophile. What I was looking for was a set of headphones that had long battery life, connected to bluetooth, and sounded decent enough to make me happy. This set of headphones hit a home run in all categories. I use them regularly but not all day, everyday. I have only charged them up twice since getting them almost 2 months ago.
I found the sound to be relatively balanced with a prominent but not boomy bass. Ive had no issues with the bluetooth so far. They synced with my computer and phone very easily. The real test will be durability. I plan to update on that soon. *1 Week Update: They have been holding up well and I have come to appreciate the long battery life. As a NYC subway rider I have found the noise isolation to be somewhat underwhelming.
All the people Who WROTE THE REVIEWS THAT WROTE NEGATIVE STUFFS BEFORE ME ARE FREAKING IDIOTS! They are probably working for other head phones companies or fan of other company who hates this brand or are jealous of it. This head phone has a really long battery life time, and it has a lot of functions that are useful. For example SD CARD Function is very useful when your phone, mp3 players or other thing's battery went out.
The good: Amazing bass, almost too powerful. The audio has a compression filter on it which can make the bass drown out the highs and mids. Super long battery life.The bad: AptX does not work, I have verified this through ADB on my phone and a bluetooth adapter that works with aptX. Considering this is the primary reason I bought these it's extremely disappointing, and false advertising. When plugged into USB it shows as CSR8645 which does indeed support aptX however it must be disabled in the firmware.
Well, I wanted what I thought was impossible-- a set of great-sounding wireless headphones that would do the following:Pair with my Android Note II phonePair with my Google Nexus 10 tabletPair with my Dish HopperPair with my Vizio bluetooth-enable TVPlug into my Xbox One controllerUse on my Windows 8.1 PCwhew..that was a tall order, and these headphones work flawlessly! Sound is super rich, remarkable tonal range, comfortable fit, and long battery life.
Answer: There is no need for battery use if youhave 3.5mm cord hooked up. Theyonly use battery if you are in bluetoothmode. TERRENCE