Strange charging patterns

[MojaveHigh]

I have an unrooted Thunderbolt, with both original and new (Rezound 1620mah) batteries. I use Battery Monitor Widget to track my charging discharging.

BMW graphs and histories show some odd patterns, on both batteries:

When charging between 0% and about 50%, I can pull about 750-850ma. I assume I can't get quite to 1a because my cable is a power/data cable. If I use a power only cable, can I do a lot better?

From about 50% on up, it starts pulling smaller and smaller current, down to about 50-60ma by the time it reaches 70%.

After a little more time, the battery will jump to 100%. Again, this happens on the new battery as well. I don't know if it's a calibration issue, a phone issue or a problem with BMW.

If I restart the phone while charging, generally it will show a huge jump, much like when it jumps to 100%.

When discharging, everything seems normal. But if I restart the phone, many times it will show a huge discharge. I will drop 10% sometimes.

There are other times, when BMW reports a flatline. That is, it is discharging with use, but the percentage charged stays the same for sometimes 30 minutes.

I don't remember having this issue when I first got the phone, 15 months ago.

Do I have to do any kind of calibration? Should I find a new battery tracker?

 

[Atomic_Monkey]

don't know but for a solid year my tbolt has not shown batt percentage over 73% (even with new batteries, rezound or tbolt) and recently only charges if phone is turned off...

 

[anon(394005)]

I'd highly recommend just using an external battery charger instead of the phone itself. That way you always have a fully charged spare battery on hand, also less wear and tear on the phone itself. I've been using the following Seidio Multi-Function Battery Charger for over a year with great success:
Amazon.com: Seidio HTC Thunderbolt Multi Function Battery Charger Includes Base Battery Charging Plate: Cell Phones & Accessories

Edit: I have two Rezound 1620mAh batteries and when I have charged them in the phone, they do have an anomaly where they'll jump from approx. 80% charge to 100% pretty quick, but they discharge normally otherwise. Also, the discharge on a reboot is about normal, for most it's probably around 5%, but sometimes can be more depending on the charge state or age of the battery.

 

[MojaveHigh]

Thanks for the replies. I didn't know charging a battery "in-phone" adds wear and tear on the phone. That's something to think about.

I'm not a big fan of changing my phone's batteries - shutting down, opening the case, then the cover, exchanging batteries, closing up the phone and case and restarting, which itself takes 5 minutes - all that seems a little excessive to me.

Instead, I have an external 7000mah battery that I can use to recharge my phone battery 3+ times. I charge the external battery off a 10W portable solar panel. I suppose you can charge extra batteries this way too, assuming they use USB.

Anyway, I guess I just have to deal with odd charging patterns on my phone.

 

[AZSALUKI]

My stock battery has always been pretty normal/consistent, but the very first thing I noticed when I got a rezound battery was that my battery stats weren't accurate at all......from day one. I monitor my battery life by my usage stats because I know very well how much up time and real up time I can get.

sent from my bolt using tapatalk

 

[anon(394005)]

Thanks for the replies. I didn't know charging a battery "in-phone" adds wear and tear on the phone. That's something to think about.

I'm not a big fan of changing my phone's batteries - shutting down, opening the case, then the cover, exchanging batteries, closing up the phone and case and restarting, which itself takes 5 minutes - all that seems a little excessive to me.

Instead, I have an external 7000mah battery that I can use to recharge my phone battery 3+ times. I charge the external battery off a 10W portable solar panel. I suppose you can charge extra batteries this way too, assuming they use USB.

Anyway, I guess I just have to deal with odd charging patterns on my phone.

Oh yeah, the constant plugging in and removing a cable can really wear on the USB port to the point it doesn't make a good connection anymore or it just stops working all together. Also, there's always the danger that while it's plugged in, someone (person or animal) could accidently snag the cord causing havoc. There is also heat build up and wear on the internally circuitry of the phone when charging, especially if the phone is used at the same time. Over time these things take a toll on the phone. That's why I highly prefer to avoid that and keep my batteries charged externally and just swap out for a fresh one. Sure there is the potential for wear and tear on the battery door, but that can be highly minimized if you're very careful (I have it down to a science in easily removing it), not to mention if need be you can get a new door for $10, much cheaper than a new phone. Also, a power off and battery pull now and then is good for the phone (and occasionally SIM card pull to force the phone to re-provision itself on the network), allows it to fully reset and minimizes operating issues IMO.

You mentioned you're using an external power pack to charge. Have you tried using the AC wall charger that came with the phone? Do you get the same results? May be the power pack isn’t working properly anymore? Otherwise, I wouldn’t worry too much about monitoring the battery charge/discharge stats (keep in mind those battery monitoring apps use up battery power too). What’s more important is: are you getting what you feel is normal/adequate run time out of your batteries?

 

[natehoy]

When charging between 0% and about 50%, I can pull about 750-850ma. From about 50% on up, it starts pulling smaller and smaller current, down to about 50-60ma by the time it reaches 70%.

I can't speak to most of your post, but the above is, I believe, normal and desirable charging behavior.

How to Prolong Lithium-based Batteries - Battery University

Adding the "last 20-30%" to a battery elevates the temperature of the battery more than the "first 70-80%". There's also a relationship between the amount of charge coming in and heating.

So while it's not bad for the battery to charge it from, say, 20% to 40% at 750mA, trying to pump 750mA into a battery that is already at 80% gives your battery a heat "double-whammy" - it's being heated because it's closer to capacity AND it's being heated because power is flowing in fast.

Most phones are fully aware of this fact and their job is to charge the battery in such a manner that the battery is damaged as little as possible on each charge, so they'll dump power in at full rate below about 50% or so, then (depending on the specific phone and battery profile) start backing off on charge speed.

How to Maximize Runtime – Battery University

The absolute best thing you can do for your battery is to get a low-power (500mA) charger and slow-charge it every time, and don't ever let your battery sit at 100% for any period of time, especially if it's warm.

But in reality, your charging circuit is already doing the right thing - limiting incoming power to something below what will do excessive damage to your battery.