Hmmm... Never heard of it and have no need. Car charger takes does the trick toward the end of the day if the need arises.
yes, we have car chargers too
Apple tests the phones and says they are working FINE
but
the batteries still go down down down fast fast fast
we will buy more apple products when they fix their battery problem!
(we have done all the adjustments or resettings we could as apple suggested, didnt help much, the apple batteries are serious problems and there are countless website complaints about them too , so its not just something I am doing