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Root Anyone know how? battery charge limiting, turn off cellular when on wifi

B

Brad N

Member
Hi, got a couple questions and not sure if anyone has tried these before or has ideas...

First, I want to try to limit battery charge to about 85%. Is there some tweak in sysfs or elsewhere that can be used to turn battery charging on or off (I could set up the rest of the program logic if I had to)?

For the other question, I'm using a couple LG Volts on FreedomPop and it would be desirable to *automatically* turn off the cellular modem entirely when connected to wifi, as all phone stuffs are done over the data connection. Mobile texting and calling aren't used at all with this service (well, mobile call-out can be used if you subscribe to a certain premium feature, but from what I can tell, the software won't use it when on wifi anyway). I know the phone is capable of this kind of operation (turn airplane mode on, turn wifi back on).

Thanks in advance if anyone has any tips for either of these!
 
Why do you want to limit the charge? As far as I understand these days the batteries in phones are different then they used to be and it's fine to just leave it plugged in (meaning it won't overcharge or something like that).
 
You have absolutely no reason to only charge your battery to 85%.

As for your second question, you could try Tasker for that.
 
Already charge phone to full. Also. Once a month... Let battery drop below 10% sms then fully charge work phone off n don't touch it until it's charged. That helps battery life.
 
phillyjb said:
Already charge phone to full. Also. Once a month... Let battery drop below 10% sms then fully charge work phone off n don't touch it until it's charged. That helps battery life.
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Actually it doesn't. Modern batteries don't have "memories". The only thing you shouldn't do is let your battery run down to zero.
 
MLSS said:
Actually it doesn't. Modern batteries don't have "memories". The only thing you shouldn't do is let your battery run down to zero.
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Ahh... more misinformation. While it is true that Li-Ion batteries don't have memories, every time you charge and discharge the battery it sets full and empty flags. Eventually these flags can reduce the effective battery life. They can be reset by fully discharging and recharging the battery with the phone off. It is ideal the keep the battery between 10 and 90 percent, but that's nearly impossible to do and it won't do any noticeable damage until the battery nears the end if it's life anyway. Monthly (at most) calibration, or whenever you notice the battery running down faster than normal, is recommended.

Source: www.BatteryUniversity.com
 
Whoa, no replies for a day and then I come back and there's a bunch...

Basically the logic I'm using with the battery is that most li-ion doesn't like spending a lot of time at very high or very low charge. When you store a battery, they recommend 40-60% charge for long term storage. I'm not worried about the brief time my phone might get below 15% or something, but I'm not so keen about it sitting on the charger at 100% for hours each day. Some laptops have an option in the BIOS to control max charge level for this reason, perhaps a little more applicable there as they tend to sit on the charger quite a bit.

Worries about "calibration" - perhaps - like many other things, it depends on the implementation. In theory it should be possible to track state of charge pretty well just staying within the 85-15% range (voltage does start to change by those edges) but it's down to how the software is written. Nothing innate to the battery itself makes this limiting a bad idea, but it could be possible for it to confuse the software. If I have to do a full charge every few weeks or something to keep it happy, no big deal.

But I'm not sure if there is even a control in the kernel that can be used to shut down charging... I guess this would be a good question for someone with kernel knowledge on these things.

As for the airplane mode question, I had seen some mention of tasker for this elsewhere as well, but I was hoping for a free option as I have a few devices I want to do this on.
 
if your phone now have any version of 5.0 on it, no app is able to toggle DATA anymore.

unless, you root the phone.
 
For the record, I've looked for charge limiting apps before and found nothing. After reading around on battery university, I'm significantly less concerned about it. Once the battery hits full, it stops charging until it dips down a certain amount, then just trickle charges to maintain until you unplug it. Running it dead frequently is far more damaging.
 
AZgl1500 said:
if your phone now have any version of 5.0 on it, no app is able to toggle DATA anymore.

unless, you root the phone.
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Not trying to toggle data, trying to toggle the whole airplane mode for the radio (there's a difference). But what you say probably applies to that as well. I'm on 4.4 though with a debloated & rooted stock ZV5.

There's also an xposed module to change some versions' behavior to match older versions that did let apps manipulate it, but I had trouble getting it to work with the one app I found that was designed to do this.

But, my battery usage regularly says over 50% power consumed by cellular standby... so I'm not sure what to think there.
 
bg4m3r said:
For the record, I've looked for charge limiting apps before and found nothing. After reading around on battery university, I'm significantly less concerned about it. Once the battery hits full, it stops charging until it dips down a certain amount, then just trickle charges to maintain until you unplug it. Running it dead frequently is far more damaging.
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Yeah, I'm probably over-thinking this part. Maybe it isn't that big of a deal and I'm tripping out over a 5$ battery that either I'll have to buy at some point or not (nice that it's still easily replaceable on these volts!), and probably doing some charge limiting isn't going to affect it enough to matter.
 
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