yashsingh1/xdaforums huggingface dataset:
[EVO 4G General] m20120:
The circuitry in a stand alone charger is likely different than the changing circuit in the phone. It could be capable of charging the battery to 100% and then disconnecting from the battery. The battery has a very low self discharge rate so it will remain at 100% for a very long time without the trickle charge that is being applied by the SBC kernel. The result is a battery that is at or very near 100% when you take it off the charger.

The phone on the other hand does not have the circuitry to disconnect from the battery. Years ago cell phones had the capability of doing this (remember the days when you could run a phone on AC power with no battery installed) but no more. The phone will always be drawing current from the battery when it is turned on. When the battery is being charged the charger circuit is supplying more current to the combined battery and phone than is being consumed by the phone so the net result is that the battery is charged. As the battery reaches 100% the phone must disconnect the charger supply from the battery and the phone. For the phone to continue to operate it must draw some power from the battery. This continues until the phone decides that it is safe to charge the battery up again. You can see this cycle when you look at the battery monitor logs with the stock kernel.

The SBC kernel attempts to keep the battery charged at 100% and supply just enough current to power the phone. The end result is that it is never removing the charging voltage from the battery and it likely over charging the battery.

The people who design Lion battery packs will tell you that overcharging a Lion is not a wise thing to do. It will shorten the usable life of the battery. It can also lead to battery failures that can be catastrophic at times.

I tried the SBC kernel for a couple of days just to see how it worked. I was impressed with the battery life that it provided but I was uncomfortable with the logs that I was seeing from the battery monitor. I am not willing to take the risk to my battery, phone, self just for the extra battery run time in the short term.
[EVO 4G General] xHausx:
The kernel actually charges to 4.2V stock. The difference is once it's there it stops charging and switches to the battery instead of the charger. All this mod does is prevent it from using the battery so it continues to charge indefinitely. After awhile the battery will quit absorbing energy but it still runs power through it until you unplug it.
[EVO 4G General] u921333:
I was pretty impressed when I bought a cheap ebay Li-Ion battery and forgot it in my pocket that went through the washer and the DRYER!! and didnt explode ..... of course I didnt try to use it obviously but was very surprised that it didnt turn my dryer into a wood burner :).

I have still been using SBC as well and will keep monitoring it for anything but so far no issues.
[EVO 4G General] u921333:
Thats what I mean by the simple test to see if it is overcharging.... Wouldnt that be easy to prove or disprove by a simple multimeter after a thourogh SBC charge? If say 50 of the SBC users did a full 8 hour charge say tested the current and all came back with between 4.19 - 4.205 or something then no overcharge or flipped say all 50 come back with 4.3 - 4.35 :eek: I think we could easily get that many volunteers to give it a go.

I just think we are talking about everything when we should just go about setting up some easy basic test that could go along way one way or another. It seems if all 50 came back overcharged and the kernel just read the voltage wrong it would be easy to say ok lets not use it. And if no overcharge exists it would at least eliminate the first item.
[EVO 4G General] xlGmanlx:
OP, have you made any further findings other than your original theory? This thread has gotten pretty extensive attention and traffic but i have seen very little in ways of actual findings. If there has, would you mind updating the OP? Thanks
[EVO 4G General] xHausx:
Can someone here post a log of their phone showing it charging and then staying on the charger until the mA reach 0? You can attach it as a .txt file or put it in a code box
[EVO 4G General] sidepart:
Sorry, what I'm trying to say is that it's probably not charging above 4.2V. The issue is that it's keeping it at 4.2V constantly instead of disconnecting the charger and letting it discharge to the top off voltage. The concern comes from leaving the charger on at all times and allowing the battery to draw from it, and there's potential (maybe slim to none) for it to draw current beyond 4.2V even though it doesn't normally do this.
[EVO 4G General] sidepart:
Exactly. The concern is that you have a live charger hooked up to the battery with the potential to draw current when it's not supposed to. I personally am ok with the risk though. I've never been very good at gambling, and so I have a feeling I won't hit the jackpot of app and kernel combinations to cause my battery to erupt in pretty red flames. But...This is TOTALLY the wrong attitude to have when it comes to engineering, I'd never take a chance like this with product design.

Sorry, I tried to say the bit about charing to 4.2V and then switching to the battery at the top where it says:

I hope I didn't counter myself somewhere in the explanation, but thanks for clarifying it otherwise. I didn't explicitly state what you mentioned.
[EVO 4G General] mattykinsx:
[In the blue]

http://xdaforums.com/show...postcount=4282

Why can't an intelligent answer be given to that by ms? or hell, anyone else!?

Interesting response, eh?

Admits to not knowing anything about electrical engineering but still defends his comment in the OP that the kernel mod will not damage the battery.
[EVO 4G General] sidepart:
Man, I keep seeing your posts everywhere. I think you have the right message in getting people to ask questions and be informed but take the intensity down just a little. I understand you're REALLY passionate about this, but I don't think this particular post was called for since it's more of an attack than helping to educate.
[EVO 4G General] u921333:
I was actually talking about the overcharging because of m20120 comment not yours sidepart LOL. I dont think its getting Overcharged either and believe the biggest issue is the constantly staying at 100% but I believe there is still a large group of people who believe the kernel is overcharging the battery while it is very possible it may I think it is very easy to at least eliminate that from the debate and move on to the other issues. In the long run I think everyone wants the best and safe solution.

And for some people who completely go to one side or other needs to relize that even though it wasnt a safety issue the FPS fix from HTC was denied over and over. so to blindly say HTC already is incorporating the best way is not giving our Devs the respect they deserve. And on the other side this could really hurt someone so you cant blindly just say im going to run it and not monitor it because it hasnt happened yet.
[EVO 4G General] mattykinsx:
With all due respect, my posts in the SBC kernel thread are in direct response to the treatment of a few select members whom would rather tell someone to "go kill" themselves than actually discuss anything.

Follow up:

http://xdaforums.com/showpost.php?p=10576627&postcount=4326

He says he is going to post a warning right now.
[EVO 4G General] sidepart:
Ah sorry! Didn't catch that. Yes, still a very good test to make sure we can verify that we're not going over 4.2V regardless. This can at least attempt to dispell any thoughts that the battery is regularly overcharging beyond 4.2 as a result of the kernel. While there still would be potential risks, it would be astronomically less risky if we're sure of this. I have my multimeter, I might give it a go this weekend.

Anyone want to lay out some parameters for a test like this? Make sure that if anyone else joins in, that they follow the same method to get their data?
[EVO 4G General] sidepart:
That's fine, it's an all out war in there. I was only referring to this one.
[EVO 4G General] u921333:
I dont think anyone is telling anyone to "go kill" themselves... Even if a warning is placed its the individual who chooses to modify anything and esp. this mod there is plenty of info that anyone modifing there phone should be aware.

The way you have this worded I picture the guy from Saw setting up the kernel to take out people :)
[EVO 4G General] mattykinsx:
The point of the warning is to allow people that don't follow or read everything [which is honestly a lot] to see that there is a potential for a serious issue.

As far as the "go kill yourself" comment, yes it did happen. It was directed toward me as well.

It was removed by a moderator though.
[EVO 4G General] xlGmanlx:
OP still waiting for an update to post #1
[EVO 4G General] mattykinsx:
http://xdaforums.com/showpost.php?p=10576954&postcount=4331

Thought this might be relevant to the discussion.

I don't have any experience in this field, nor have I ever claimed to, so I can't comment on it.
[EVO 4G General] u921333:
Oh I thought the comment was about the mod doing that my bad :).

But thats sort of the problem with the warning as well LOL if they dont read or do any research how many of those same people read the warning. Now I for one read everything and think all possible issues bugs or any other thing should be spelled out so I agree if there is even a remote possibility put warnings for it but I also still think those people who dont read will bypass the warning to as seen in about every ROM in the development section for example the does 4g work on the AOSP roms lol.
[EVO 4G General] mattykinsx:
I understand your concern but at least it's now there, and there isn't a comment saying anymore "this will not damage your battery".
[EVO 4G General] raiderinks:
The overvoltage condition is not the only concern.

I intend to. I am still trying to find someone to help me (from the EE side), but MS still hasn't responded to me. I might need the help of someone other than him that can read kernel code to contribute as well.
[EVO 4G General] xlGmanlx:
i think you could agree in the future attempting to find help to audit that data to ensure best possible quality would have taken priority over creating a thread prior to doing any type of due diligence

and i don't even pretend to be a programmer or dev, i would imagine his portion on GITHUB for the SBC would be small in comparison to the rest of the kernel, i could be wrong though. I would imagine anyone that has basic programing could be able to translate that for you....just a thought
[EVO 4G General] sidepart:
It's straight from wikipedia and I don't really think there's anything incorrect about it. Still though read what it mentions in there. It's what the stock HTC kernel is doing.

First it'll charge up to 4.2V:

And then it switches to battery until a top off charge is reached:

The SBC kernel doesn't do that. That's the problem, keeping it at 4.2V constantly can reduce the life-cycle of the battery. This explains why the military keeps their long-life cells at 3.92V.

So, if you don't care about battery life-cycle, cool...that's one thing. The other thing is that the kernel never let's the battery discharge to the top off voltage. That's fine as long as you can keep the battery at 4.2V and make sure it NEVER EVER EVER has a chance to go higher than that. That's not so easy to do when it comes to trickle charging. That's the source of the potential risk although it's hard to determine how much of a risk or how big that risk is. Suffice to say that it's not the kind of thing you want to risk when designing a product. That being said, feel free to keep using it but just keep it in mind eh?
[EVO 4G General] u921333:
Yep but we have to start somewhere seems like the easiest item to clear of the list or if it did overcharge consistently then I think we could put it all to rest. If that becomes a non factor we can focus on the next possible issue on the list.
[EVO 4G General] u921333:
Im a SBC user but not sure I would want to rely much on anything from wikipedia LOL my friend posted a page that his B-day was a national holiday so always a little suspect on those pages.
[EVO 4G General] sidepart:
Haha well from what I could tell, the article on Wikipedia isn't really untrue and provides a decent overview...but it doesn't really do anything to defend SBC...unless the poster was trying to point out the safety features included in Li-Ion cells? If that's the case, big deal...you don't WANT your battery to trip any of those features, your battery will no longer work.
[EVO 4G General] raiderinks:
I am tired of your off-handed suggestions that I lack ethics. I did my due diligence in the form of researching batteries to the level that was required to debunk the statement that MS made regarding the safety of his kernel. As I have stated before, HHS issues involve preventing catastrophic failures from EVER happening. That is not translate well to me performing simple tests because I don't have the experience that tells me how close to the edge is ok.

But I do know what is unethical. It is unethical for MS to state unilaterally that his charger is safe without any legitimate explanation why.
[EVO 4G General] xlGmanlx:
it wasn't off handed but i will abandon tact and professionalism to be more direct. Other than publishing your highly inflammatory thread with has no RELEVENT FACTS and in which you have volunteered you are no expert, what exactly is your intent? You have done no due diligence and your "reports" have been speculative at best and are borderline negligence. I would submit until you provide any shred of applicable data that you take your highly touted EE and either update with facts or be silent. You have proven nothing other your unwillingness to handle the spotlight you thrust yourself into nor any basic problem solving skills when the very Dev you slandered with theories isn't exactly bending over backwards to help you insult his code. I would highly suggest before you make your next baseless claim that you actually have some sort of contribution and eliminate your condescending tone to any who challenge your significantly subjective claims. How is that for direct?

the exact inverse would apply to you as you have made statements in which you have not been able to provide any quantifiable data or findings to support without even looking at the code! i had to point out all of this was public knowledge in his github that was up to date further illumination your lack of research as it was news to you. I won't question your character nor do i think it is being questioned as that isn't what this is about, however it seems puzzling how you have yet to address any request towards yourself for any follow on data

Some one PM me if there is actually any shred of actual data provided otherwise consider me unsubscribed to this tabloid
[EVO 4G General] DrRyder:
I love you, Gman.
[EVO 4G General] raiderinks:
You are far too worked up about this. As for how direct it was, I think those were more direct, but not quite directly calling me unethical. Like I just said in the other thread, and like I have said here about 10 times, my intent was to debunk the logic used to claim that the battery was unilaterally in no danger. I presented plenty of facts to support that claim.

Now, as for updating the OP with additional facts (aka further findings), you have to show some patience. Until yourself and raiden turned vitriolic, I had only continued posting in this thread to answer questions.

I provided sound logic and linked to my resources when disproving the logic he used to claim his kernel was safe for the battery. That is one issue.

Offering to go through it with him, together, to try and prove (correctly) that it is safe is a second a separate issue. This one is going to take some time. Seriously, what is wrong with that?
[EVO 4G General] xlGmanlx:
i would disagree that i am worked up as my writing was direct but not excessive. Not only that i would submit that it maintained professionalism and avoided childish insults and merely stated my position. I understand your position and i would submit you have done nothing to reiterate that there is in fact bad scenarios for battery charging but have also failed to correlate them to the battery mod listed in the github. I am simply stating if you have facts present them, otherwise adjust your thread to reflect the current climate. Just as there has been requests to posts disclaimers, i would think the same applies to your charter as you need to disclose there is no smoking gun nor publishable data. If that should apply to devs, why wouldn't the same logic be applied to your statement which is still in its development/research phase?
[EVO 4G General] z28marols1:
You guys still dont get it. Overcharging is a concern, but not the main one. The problem is that holding a battery at its max voltage will cause ion plating on the anodes, which will eventually cause the cell to short itself, which will cause a catastrophic failure. The only built in protection that the battery has againt that is venting.
[EVO 4G General] raiderinks:
Ok, I think I understand you better now. However, I disagree that an update to my OP is needed at this juncture. My suggestion that people not use SBC until further investigation still holds. I was unaware that people expected me to use the OP as a status board. However, if you just want a line that says I haven't reviewed the kernel yet, but MS and I are working on it, I don't see any harm in that.
[EVO 4G General] akarol:
www.batteryuniversity.com. Period!
[EVO 4G General] xlGmanlx:
i don't discount your efforts and i think we can all benefit from the fruits of its labor. With that being said much can be done in the interim like changing the wording of the post to more accurately represent the theory/thoughts and quantify it with a [WIP][Battery testing] type of syntax prefix.

You would be surprised how useful it can be to keep your OP up to date as to not have to answer repetitive questions as this is how we have been conditioned to behave.
[EVO 4G General] wfrandy:
Excellent post, good to see someone here finally gets it. Their is in fact minimal danger of overcharging with the SBC kernel. The only problem with the SBC kernel is that it keeps the voltage applied to the battery to keep it topped off, or holds it in a fully charged state until it is removed from the charger. This is the part that is very bad for lithium ion batteries. Keeping the voltage applied basically turns the battery into a plating tank, resulting in internal ion plating or corrosion buildup.

The only thing I disagree with is that their is no risk to the phone itself. If the plating/corrosion inside the battery from holding it in a charged state is allowed to progress far enough, it can cause the cells to short out. This would lead to thermal runaway which could cause the battery to explode or catch on fire. Either of which could result in significant damage to the phone. Their is no protection in the battery against this condition, except for the battery to vent. If you are lucky, the battery will just vent and be destroyed, but not catch fire or explode, with minimal damage to the phone. So, do you feel lucky?
[EVO 4G General] blunden:
This video shows the li-ion cells in a laptop battery venting one by one as a chain reaction.

Yes, and as we can see it's kept at, or very close to the max spec constantly when it reaches it. That will, at best, significantly decrease the total lifetime of the battery. I think that has been made clear time and time again that the cells don't like that.
[EVO 4G General] gx1400:
Not sure if this has been noted yet. But this is a pretty descriptive article about the charging of Li+ batts.

http://batteryuniversity.com/index.php/learn/article/charging_lithium_ion_batteries

I'm a fellow electrical engineer and although batteries aren't my specialty, I've been wary of these kernels since day one.

I won't restate what has already been said, but I think its worth noting that the informed people here are the ones who seem to be concerned and the uninformed are the ones who are shouting and freaking out because they want proof. Frankly noone heres probably has the resources or equipment to provide incontrovertible evidence you want and some of us who have the knowledge to do so, could care less if you fry your battery/phone/burn down your house. You have been warned of some engineers' concerns. Act accordingly.
[EVO 4G General] v01rider:
and anything posted on youtube is true!
[EVO 4G General] v01rider:
so i will have to buy a new battery sooner than others or i might have to use my insurance to get a replacement evo. :D worst case, i might catch on fire will using it. :D
[EVO 4G General] kf2m:
Can I also point out that battery quality plays a part in this as well. Those cheap Asian knockoffs that you find on eBay I don't trust. Most of the battery fires a few years back in laptops where caused by either 3rd rate/3rd party batteries, and/or chargers.

A good grade L-Ion will last you almost 3 years since L-Ion batteries degrade over time. The knockoff's are hit or miss (mostly miss). In one vent with flame incident the investigators found that the 3rd party battery had no protection circuitry what so ever.

With that said has anyone considered looking into what batteries were being used that failed?
[EVO 4G General] wuclan48:
Furthermore, the uninformed are advocating fraud!
[EVO 4G General] v01rider:
hahahahahahahahaha
[EVO 4G General] v01rider:
what about those like myself that keep their laptop plugged into ac power or docking station when the battery is fully charged? o, i better be scared my laptop will catch fire. :eek: hahahah riiiiiight :D attached is a screen shot off my laptop and it is working just fine. always has, and always will be fine with battery in, fully charged, and on ac power.
[EVO 4G General] Award Tour:
Did you modify the charging behavior of your laptop?
[EVO 4G General] scooter185:
Unlike your phone, your laptop is running off of the AC power while plugged in. The battery is charged and then not touched. You can remove the battery and still run off of the outlet alone. With the evo that kind of circuit is not present, so the phone is always using the battery, and never uses the AC power from your wall.
[EVO 4G General] blunden:
I don't think you understand what insurance (and probably warrenty) is for. No wonder we see so many locked down phones. :(

Certainly not. :) However the same behaviour has been shown countless times and is well known. The batteries should hopefully vent less voilently but these things certainly do happen. Also, it's kind of indicative that they sell fireproof bags for storing li-ion batteries. The batteries in the phones have more safety features than those used in RC and robotics so the chance of mistreatment is probably much lower but it can certainly still happen, things are seldom perfect.

Exactly. This has been stated several times in this thread but since some people seem to miss it was good that you restated it. :)
[EVO 4G General] mlin:
So, just to be clear:

Overcharging the battery is what leads to the potential dangers, correct? And you are conversing with MS to confirm this is NOT in fact overcharging the battery, right, but at this point you don't quite know what's going on with the SBC method of charging?

I guess my opinion is this: If overcharging is the concern and a dozen different battery monitoring programs are showing that the battery is not charging above 4.2V, then why is it not safe to conclude that the battery is not being overcharged and that MS was infact being honest and up front when he said it would not overcharge the battery?

Also, is it true that there is a built in overcharging prevention hardware to the batteries? If so, would exercising this hardware more with the potential of overcharging more readily lead to its failure?
[EVO 4G General] scooter185:
The programs are only lines of code, and can be fooled, not that Im trying to imply that's the case. But IMO the only sure way would be to use a multimeter to check the voltage and amperage.