On Thursday, 15 June 2017 17:50:56 UTC+1, Jeff Liebermann wrote:
On Thu, 15 Jun 2017 11:43:36 +0100, Mike Coon
wrote:
I have a 2 year old Motorola MotoG3 smartphone. The instructions say:
"Motorola batteries and charging systems have circuitry that protects
the battery from damage from overcharging." So recently I did not worry
about leaving it connected to a 5V charger for hours at a time to ensure
it was always ready for use.
The first symptom was that the flash/torch LED did not light up; I
wondered if, since this is software mediated, it was a fault in the
Marshmallow upgrade at about the same time.
Then recently the screen has popped out of the housing, leading me to
suspect that the battery was not protected as specified and has bulged
badly. Discussion with Motorola support led only to the offer of a
charged repair, though I argued that this counts as "unfit for purpose"
under UK law.
So I have a replacement battery on order and have removed the old one
which has indeed bulged. It may even have bent the motherboard which is
reflective enough to show a convex mirror effect. Also the connection
between the motherboard and the flash/torch LED is just by spring
contacts next to the battery, so a bulging battery has probably caused a
disconnection. Thus the failure of the flash/torch LED could have been
diagnosed, by anyone who knows how the phone is designed, to be caused
by incipient battery bulge long before it got to the point of screen
ejection.
Any comments?
Mike.
1. Find a USB ammeter and measure the current your phone is drawing.
Something like this:
http://www.ebay.com/itm/222307766211
If you see any current being drawn after you battery is officially
done charging, then the Motorola charging circuitry in the phone is
NOT working according to your quoted description. I have a 1st
generation Motorola G3 phone that I can try it later tonite.
2. LiPo batteries tend to bulge when charged. There are numerous
examples of the problem:
https://www.google.com/search?q=bulging+cell+phone+battery&tbm=isch
Here's a rather sane discussion on the causes of bulging batteries:
https://www.quora.com/What-would-cause-a-phone-battery-to-bulge-in-the-middle
Basically, what's happening is the electrolyte is breaking down into
gasses inside the battery. I don't know what might happen if you take
a needle and punch a hole in the battery, but I wouldn't recommend
doing that. In any case, replace the battery.
3. When something like this happens, there is always a tendency to
search for a suitable culprit. Is it the charger circuit in the
phone? Is it a faulty battery? Is it something that you're doing? Do
you discharge the battery until it's totally discharged, which
incidentally is a great way to kill a LiIon/LiPo cell? It the
charging system sensitive to temperature, humidity, usage, or phase of
the moon? Maybe the battery has hit its limit of charge cycles?
Perhaps you might have a counterfeit battery? Or is it some
combination of these factors? I can't tell without more information.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Hi Jeff, apologies for the apparent lack of appreciation for your reply (though some of it was a bit obvious!).
I am actually quite familiar with bulging lithium batteries and have a collection of mildly obese ones, mostly due to keeping a device on a charging cradle unnecessarily. Fortunately they are user-replaceable batteries. What is new to me is a non-user-replaceable battery with instructions that state it cannot be damaged by overcharging. However since I am not a mere "user" I have obtained and fitted the new battery. At least disassembly was largely achieved by the battery!
A smart phone has enough potential intelligence to cycle its battery through whatever charge/discharge routine is required to keep it in lean health. It is a pity this routine is not enforced...
Mike.