[ThePom]

Hi, I’m a layman and new here so please excuse me if you think this is a dumb question.
I’ve been using Bluetooth headphones for several months and they always pack up after a short time.
I always buy at the cheap end of the market and I’ve been treating them as a smartphone and recharging when I get home after using them, even if they are only slightly drained of power.
I bought the last 2 pairs about 2-3 months ago – an Avantree jogger (about $40) and a Sony MDR ($80) , both quite cheap but by no means the cheapest.
With both units, you connect the USB cable and a light comes to show they are recharging – but at about the same time they both stopped displaying the light to show they were recharging.
With the Avantree, it wouldn’t recharge at all and stopped working. I took it to a technician and he said it wasn’t fixable.
With the Sony, it is still working but the recharge light is also no longer displaying so  don’t know if it’ll also stop working when it’s lost all its charge.
I told a friend and he laughed and said that by constantly recharging the battery I am draining it of memory each time and thereby destroying it.
I can’t believe this. Wireless headphones have been around for years, haven’t they? I read one website that even said in order to be able to sell bluetooth headphones in the US, you must demonstrate that it cuts out the recharge in order to protect the battery.
Please tell me:
1) is there any kind of in-built headphone battery that prevents overcharging? if so, I'll only buy those devices
2) Does it sound like my units are destroyed or is there anything that can be done?
3) Are there any brands that are known NOT to overcharge – and if so, must you buy top-end units only?
The problem is, with the headphones I buy there seems to be no light that comes ON to show that it needs recharging, so you can only guess how long it’s been since your last recharge.
Any advice much appreciated, thanks

 

[PurpleAngel]

I believe most lithium batteries are designed to stop recharging once the battery is full recharged.
But it's not perfect, so best to stop charging right after the battery finishes recharging.
Maybe try not to let your batteries (used in your devices) to recharge for longer then 2 or 3 hours.
That should be enough time to at least mostly (or fully) recharge the batteries.
 
Lithium battery seem to retain a memory of what level they were recharged from.
So if you keep recharging the Lithium battery when it's is only 10% discharged (still 90% charged), after a while it will act like it's run out of power after only using that 10% of it's power.
So every once in awhile it's good to run the lithium battery all they way down until it's almost drained, like 90% discharged, before charging it, to get the "full memory" of the lithium battery working.
Also if you run a Lithium battery all the way down to 0 power, it may not be easy to charge it again, you have to use a very low powered recharge to bring the battery back.
You like, most people, to not really have a way to control the amount of power used to recharge a Lithium battery.
 
I myself have a $40 Lithium battery charger, that allows me to do a really low power recharge (or discharge) of the batteries I use in my flashlights.

 

[ThePom]

thanks but I can't believe this is till the case in 2016. You can recharge your phone hundreds of times without worrying whether the phone is ready to be recharged and without worrying if you've recharged it too long. You might lose a little of its life but you'd never notice. With headphones, you can destroy the entire device by getting it wrong? 
and what about that claim that you can't sell devices like these in the US unless they have a safety protection built in to prevent them overcharging?
this is a shocking situation in this day and age!