9-Cell HD Battery Reads "4.8% Wear"

It would be pretty asinine of the manufacturer to set the battery's firmware to allow it to discharge itself into oblivion.

 

The manufacturer is not at fault here: this can be from simple/normal cell wear and product-to-product discrepency.


This is like playing russian roulette with your battery.

If it is working - just use it.

 

all i can say is no no no. All PCB/PCM have the X voltage lvl that is considered the safety point for li-ion batteries. The batteries can still go even lower than that they just don't for 2 main reasons.

1. Going below X voltage will damage the cells

2. Going below X voltage will make the cells to weak to accept a recharge (unless you do a deep charge, which may/may not bring it back but will leave it with a good chunk of capacity lost)

Also this X voltage is a generous one. Going to that X voltage by no means will damage a cell. As i said Li-ion batteries are rated for 300 full discharges AND THEN will still have 80% capacity.

For an example, Your cell phone. It is best to use your cell phone dry. You will get far more use out of it than plugging it in every night or any chance your near a charger. If you plug in your battery left and right and do a bunch of little charges that'll cause far more damage than getting the full use. My dad's cell phone batteries die with in a year becuase as soon as he gets in the car he plugs it in. Mine have lasted 2 years because i make the cells do a full discharge sometimes making the phone last for 2 full days.

Side note, i am not going to bother looking up the safe voltage...i am too lazy but you will never damage a battery by fully draining it. Unless you do what i said with the drill. If you drain it all the way and than continually messing with the battery to drain it past that lvl. My drill will shut off when the battery is 100% drained but you can still get another 30-120s of use if you try to use its again because the voltage will go up slightly when left alone and then if you keep doing that 5-20 times it will stop working the battery will be toast. Read reviews online on craftsman's li-ion drill. You will see people complaining that the batteries fail to recharge. That's because the idiots keep using it after the PCM/PCB kick in.

 

Update... I have seen the gauge go anywhere from 2% to 7%, I am not worried about it. I am not going to mess with a "calibration" unless I ever have battery problems .

 

well good luck and have fun! If you ever need help feel free to pm me

 

No reps!

What you're totally basing your reasoning on is that the manufacturing process is an exact science. It isn't. Sorry.

 

correct it isn't but it is a well accepted standard that is accurate in almost all situations. Just like hardrives are supposed to last 5 years but some fail earlier than later. Also I have never heard or seen a li-ion cell be damaged from a full drain. Those limits are set well above danger lvls. You will find that all research and testing agree even if you refuse to believe that it's true.


EDIT: as your phrase says wisdom listens

 

DCMAKER,

I am listening.

What I'm saying is that I've seen multiple batteries die in less than 3 hours with the 'leave at BIOS' recommendation. At least a few of those were 'brand new' too.

While theoretically you're correct (and I've been agreeing with you, all along) I can't shake the image of a working system borked by 'experimenting' with trying to get a few more minutes out of the battery system.

Thanks for your patience with me - but nothing I've tried in the last few decades has increased the life of the battery to the extent of the risk involved. So, I can't recommend others to go down that same path which has been so unfruitful and sometimes even costly (I don't think you remember the days of the $800 batteries? ).

 

i dont remember those days because i wasn't born yet....i am 22 Also i don't mind doing trial and error This program intrigues me ^^

 

Lol. So now you've actually seen brand new batteries killed by leaving the computer on the bios? Now I know you're just joshing. I've actually drained batteries to the point where they won't even flash the power light before. Can't say they never recovered by plugging them in.

 

I think he is referring to way back when before i was born (jk not that long ago) I don't think he was referring to current generation. I think he was referring to at least a few years back

 

This advice goes against all recommendations for Li-Ion cells. And it is completely opposite to my experience with laptop batteries, phone batteries and my iPod. If you were talking about NiMH or NiCad I would agree with you.

 

how is it opposite? Find documentations showing that you get more power and life by doing 4 quarter discharges compared to one full. Find me tests done showing that you get more use and capacity that way. You won't because that is not true.

EDIT: Now if you use 25% of the battery and that's all you need and you plug that in than yes that's better than a full discharge but if your doing what i said above that is much worse.

 

The reference I use is the "Simple Guidelines" at the end of How to prolong lithium-based batteries and other places in that site.

That is what I say you should do. What you said you did was to run the battery to zero charge and then recharge. That is considered bad.

You also mention what your father does. I don't believe what he is doing (keeping it plugged in when in the car) is going to damage the battery. The only reason it should is if the charging works differently to in a laptop. A laptop with a Li-Ion will charge the battery to 100% and then stop charging. It then waits until the charge level drops below a certain point (around 95%) and then recharges it to 100%. If the laptop is never unplugged the discharge is due to self-discharge of the cells and current draw from the protections circuit and takes between two and three weeks (older batteries will be faster). If the phone charger is not working like this, there could be a problem.

But, thinking about this, it depends on how much the phone is used. While the phone is on, it is constantly using power. When a call is made or received, more power is used. If the phone is rated at four hours of talk time, then 12 minutes is about 5 percent which would mean that charging would kick in (using the laptop method above). It wouldn't be hard to trigger this once an hour. But, I don't believe that this would cause the battery to die. It is more likely that either the battery is dying because it is being used a lot (if you use constantly, there is a lot of recharge cycles whether it is plugged in or not) or maybe it is sitting in a hot place in the car. Heat is more likely to damage the battery than charging it.

 

"The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. I must hasten to explain that the pack does not die suddenly but begins with reduced run-times."

This is a bogus statement. All laptops i have own have been plugged in 24/7 and have done high drains all the time. My laptop came with only 40-50mins life watching video and 70-80mins with pushing everything to the lowest lvl and i still get the exact same capacity. Yesterday at my appointment I got 80 mins...which is longer than normal for me. My battery never gets hot just chillin in the laptop and my laptop puts off a god offal amount of heat. I have had this for 12 months and get the same...if i get less its not more than 10 mins...if that. And this thing does nothing but high drain. 6 cell battery gone in 45-80mins....that's high drain. Running like a champ. I do full discharges all the time too because i only get 45-80mins and 80 mins is lucky. Just saying blown out of proportion.

EDIT: btw all cell phone i have seen and that's about 10 do not run off A/C power with battery in. Once the cell phone is fully charged it runs off battery. All phone i have owned/used have done this. My phone will drain and recharge 3-4 times in the middle of the night....which is not good for it. Won't even loose a bar and starts to recharge for like 5 mins...waste full. Laptops are at least intelligent enough to not do this. Not sure if current smart phones have fixed this issue but even my nokia E71e does it and its a newer phone.

EDIT: I see no evidence showing that multiple partial discharges do less damage than a full one discharge. When I say this i know that a full charge does more damage than a 1/4 discharge but no where does it show any empirical evidence that 4 1/4 discharges and recharges do less than 1 full discharges and recharge. What they say is vague and can mean anything.

 

Batteries have gotten a lot better in the past 4-5 years. I am fairly certain that the articles in batteryuniversity come from the early 2000s, (like 2001-2003) when things like that were much more common. For example, my old Compaq Presario R3000 series would chew through batteries at the rate of 1 a year... if I was lucky. This Gateway NX860XL that I'm using now (bought in... 2006, as I recall) has gone 4 years, and the (original!) battery has 26% wear and still runs just fine.

 

The statement is not "bogus", the effect is dependent on the laptop. Firstly, if you read the full page, it includes a table showing experimental results of storage of Li-Ion cells at different charge levels and temperatures. This clearly shows that warmer the Li-Ion cell is, the longer it will last.

As to temperature of the battery in a laptop, I have the same experience as you. Nearly every time I have pulled a fully charged battery from a running laptop, the battery temperature felt like it was at room temperature. The only time this has not happened was on a 40ºC day when the laptop was running on AC doing video encoding, it overheated and shutdown. While I was working out what happened, I realised how hot the laptop was and checked the battery temperature. It was noticeably hot.

So, how hot the battery gets, is determined by the design of the laptop. If the hot components of the laptop are near the battery, there is a good chance this will warm the battery and speed up the aging.

OK, that's a design decision by the phone manufacturers. I don't have enough knowledge of the phones to know if this is the same for all. I suppose it might simplify some circuits.

Isn't that what I described for a laptop? Charges the battery to full, turns off the charger, waits until the charge level drops to a predetermined point and then starts charging again. The phone is just doing this. But if the phone is running off the battery even when plugged in, it is using battery charge and will get to the recharge point. My cheap Nokia phone has six bars for the charge level, so each bar represents about 17% charge. If the recharge point is the 95% that is common for laptops, then it sounds right that the recharging starts before it has dropped by one bar. As to it happening 3-4 times during the night, that is purely dependent on how much power the phone pulls and the capacity of the battery. A bit of maths says that if it recharges at 95% three times in eight hours, then the standby time of the phone is about 50 hours.

As to this being bad, I don't know. My reading says that there isn't a problem, but I don't have any practical experience with this. I charge my phone when It has dropped a bar or two and I am near the charger and unplug it when I notice the charging has stopped. My current one is about two years and still getting a decent battery life.

You are correct, I don't believe they have empirical data for it on their site. But, I haven't seen any empirical evidence that shows the opposite. The BatteryUniversity site is a reasonably clear statement of facts. My experience agrees with what they say (for Li-Ion and other types of rechargeable batteries) and haven't seen any hard evidence to suggest they are are wrong. If you can point me to it I would be happy to read it.

 

I agree that the articles are getting old (in internet years anyway). The site has been restructured recently and there was some updates. A problem is that there is no real competing site. I would like to see an alternative source that I feel I could trust as much.

As to life of the batteries, I don't know. I am still hearing people complain their batteries are dead after a year and others saying they are still going string after four years. Personally, my experience is good. The battery in my last laptop was giving about 20% less life after 2.5 years with no special treatment and plenty of use (at least an hour a day on my commute, always in the laptop). I don't have figures for previous batteries, but they seemed to last for years.

 

From the guy that wrote BatteryCare application: BatteryCare

 

That's an OK summation of the information. And apart from the Windows specific things, it isn't much different from the pages we have been arguing about. In fact, if you look at the references at the bottom, two of them are for the BatteryUniversity. The other is a Portuguese Apple page that Google translates to say the same things.