Battery Looses Power Over Night

Does anyone else's battery loose part of its charge overnight? Mine in my w3j lost 2% of is charge overnight sitting in the laptop.

 

Is it powered off or just in standby?

Standby still takes a little power, but powered off or hibernate shouldn't.

 

It is powered off.

 

someone correct me if i'm wrong, but this is a common thing. it's not good for the battery to be plugged after it is at 100%, so i believe the battery drops a little of the charge to reduce battery wear.

 

this is after being plugged in, the unplugged and put in my case. When I go to start it up again, the battery has lost some of its charge. I never noticed this until recently.

 

Hibernate shouldn't use any power? My U1F battery was fully charged, then hibernating for a while, then was at 92% when I started it up again... it seems the only time that the battery doesn't lose any power is after I shut down, and remove the battery from the laptop.

 

thats wierd. It should not be drawing power when the computer is completely off or hibernating. Because it is suspending to disk, how could power still be drawn? Correct me if I am wrong here, but if it was drawing power when suspended to ram that would be one thing, but not to disk.

Like I said, I have had the laptop for a little over a month, and had never noticed this issue before until just recently. They are going to cross ship me another battery, so I hope that might be the issue. I really dont want to ship the whole unit.

 

Here's what happens sometimes for me. I have charged my laptop to 100%, I take it to work, turn it on with the AC plugged in, and the battery states 97% charge, but won't charge the last 3 percent.

I then remvoe the battery, while keeping the notebook on, because the AC is plugged in, then place the battery back in, and usually that would give the notebook the correct reading of 100%.

Sometimes I would have to restart the notebook for it to say 100% charge.

Other than that I don't worry about that 1-4% loss of charge because I do believe the battery is 100% charged, it is just that for some reason windows incorrectly reads it and thus making it seem like the battery is losing charge.

However, this may pertain to you, it may not, atleast your getting another battery.

 

Does your charge light come on then, or not?

 

this happens with all notebooks. my fujitsu does this all the time, and i never remove the power cord. i put my computer on standby while it is still on ac, and when i come back while still on ac, it loses a few percent. when it happens with me, it depends...sometimes it recharges back to 100, and sometime it just stays it 97ish%. don't worry about it.

 

I decided to test that battery last night. After charging it to full, I pulled it out of the laptop. When I put it back in, it had full power.

My second test was to charge the battery to full, and leave it in the laptop. When I returned 6 hours later, it had lost part of its charge.

What could be causing this?

 

You guys aren't alone. I mentioned this a while back, but no one payed any attention. My Z96J battery will discharge at about 1% per hour when plugged into my laptop while it is completely powered off. As Rosemarycane tried leaving the battery out of the laptop, I did the same about 6 months ago. Similar results; no power loss even after a good 4-5 days. However, that much time with the battery in the laptop turned off, and it is will below 40%.

I have one thing new to add, which I also noticed 6 months ago. The area on the bottom of my laptop directly under the touchpad heats up while the laptop is completely powered off. It will do this regardless of whether the AC adapter is plugged in with the battery, without the battery, or just the battery.

Therefore, there is some component that is constantly drawing a small amount of power, most of which is being converted to heat.

That is all I have to say.

 

jpz, what you are describing is indeed a problem. however, it isn't the same issue as rosemarycane. rosemarycane loses only 2-3 percent when having the notebook plugged in overnight.

as i explained, it is bad for a battery to be plugged in to its charging source if it is already at full capacity. it will drop a few percentages in order prevent future problems on the battery.

 

I'm sorry, but you are quite confused. It is the same problem, just with a different model. Read through the entire thread. Rosemarycane's laptop loses charge when she leaves it overnight **unplugged** in her case. Mine will do the same. I will get back to this in a moment, first I must address this:

You are quite misled. First of all, yes, it IS bad for a battery to be OVERCHARGED. However, it is not bad for the charging circuit to receive power constantly. There is a special microcontroller which monitors the battery, and will keep stop charging it when it is full. It is by no means bad to leave a laptop plugged in while the computer is off and the battery is full. Trust me, if the power circuit continued to try to charge the battery, you would not have a house right now.

If you read the above closely, you would note that once the charging process is ended, it is not continued until the next time the ac adapter is connected. This explains why when your "it will drop a few percentages in order prevent future problems on the battery". Your observations are correct, but your explanation is horribly incorrect. When your battery reaches full capacity and it stops charging, the issue which this thread is dedicated to begins, thus slowly draining your laptop. The charge circuit does not "drop the battery a few percentages", but rather it lets the battery discharge naturally.

I should also address the issue of having your battery in your laptop while using it and the battery is fully charged, since that will inevitably arise from this discussion. Leaving your fully charged battery in a powered on computer is in no way harmful to the battery. However, HEAT can damage your battery. So if your laptop runs hot, or if your case transfers heat from the main components to the battery, it may not be a bad idea to remove your battery from your computer when not charging it.

Finally, I will further address this statement. Rosemary and I have the exact same issue. The laptop drains the battery when neither plugged in nor turned on. Mine just drains slightly faster. Obviously if power is being drained from the battery, it must go somewhere. The energy lost is usually converted to heat energy. I have located the source of heat loss in my laptop, while Rosemarycane has not located a source of energy loss.

 

if you read the posts, op doesn't explicitly state that it was unplugged overnight. just that it was plugged and then unplugged. could mean that it was charged overnight then unplugged the next day for commute.

also, you are reading more into my post than i put in. i said nothing of the charging circuitry causing the drop in battery. i specifically said that in a vague way because i was unsure of what the mechanism was, just that the battery drops charge for some reason, and this in effect probably works to prevent overcharging.....and i am well aware that there is a sensor that makes sure the battery doesn't overcharge, but just like most things, there are usually a more than one way something works to prevent failure.

and it is untrue to say that there is nothing wrong with keeping your battery in all the time while on ac. other than the heat issue that you brought up, the battery will put it through small discharge cycles, i.e. dropping some charge and then refilling it, many times, which causes wear on the battery.

http://www.laptopbattery.net/notebookbatteries_life.html

question to rosemarycane: on the last test you just ran where you kept the battery in the notebook, did you have you ac plugged in?

 

I'm sorry, but you must learn to read more carefully, and think before you speak.

I have read nothing into your posts. I have corrected your errors and supplied more information for the benefit of those reading this thread.

If you read the posts, the only person who said anything about anything happening when a laptop is plugged in has been yourself.

To quote Rosemarycane:

Second, I said that there is nothing wrong with a laptop being connected to a charging circuit while fully charged. However, if the battery(being connected to the charing circuit) is exposed to excess heat from the laptop, it would not be a bad idea to remove the battery.

Now to address your "continual charging and discharing theory". This, at the present, is incorrect. I have already told you that once full, the battery is not charged again until the ac has been disconnected and reconnected. The battery discharge rate while running from the AC is identical to that of storage drain. Meaning next to nothing.

Just to make my point clear: I have owned three laptops over the last three years. My father also has a laptop in the house, as does my sister. I have used all three laptops heavily; one I parted and sold on ebay(which is why there are only two in my sig). Between these five computers, not to mention all the computers I repair on a monthly basis for friends and family, they are all used substantially while connected to AC. Many of them, actually almost all but my two, run very hot. Between the heat and your alleged "continual charge and discharge" the battery should be shot after about 2 months. It shouldn't take more than a few weeks to use the batteries' approximated 800 charge cycles.

Honestly, taking your computer to the nearest coffeeshot, etc. and using it on the battery for 45 minutes has a greater effect then leaving your laptop plugged into the AC with the battery in it for 3 weeks. Beyond that it may be a good idea to discharge the battery monthly(as recommended to maintain battery health).

 

i keep my notebook on ac all the time with the battery in. sometimes when i boot up my computer, the charge is less than 100%, and after awhile it eventually gets back up to 100%. during that time, my ac is in the entire time. there is no disconnect/reconnect.

and the quote you had of rosemarycane shows exactly the ambiguity i am talking about. i was not saying that i was right about whether it was plugged in or not, but that it wasn't 100% clear on whether it was in or not overnight.

 

To clear things up: I fully charge the battery while working on AC. Then I power down the laptop (with the battery still in), put it in my case. In the morning at work when I plug it in, I lost 2% charge or it says charging when the battery reads 100%.

This behavior cannot be characterized as normal because that would put constaint strain on the battery: losing 2 percent then charging again in a constaint cycle.

 

thanks for clearing that up. perhaps you should try keeping it the battery in without ac for a longer period of time to see if there is a greater loss than 2%.

 

Of course it will be greater than 2%, because liIon batteries drain naturally over time, even when power is not being drawn from them. The real question is what the discharge rate is.

2% discharge over night is not too much more than the natural discharge rate of a LiIon battery. My problem is far greater; I can unplug my laptop from AC(fully charged), take it to school, and power it up 4 hours later. By the time I load windows( <50 seconds) I am already down to 92%. If I unplugged it the night before, it would be more around 80% upon first power-up.

 

why have you not contacted Asus about a repair? Are you out of warranty?

 

Me? I have a 3 year warranty. 2 and a half left. And I'm good friends with Eddie from G2P, from whom I purchased my Z96 barebones.

It's not a defect with my specific computer. This is present among all the Z96J's as far as I know, but no one has noticed.

If I don't want my battery to run down so fast like that, all I have to do is remove it when I unplug my laptop.

I also have a 9 cell which I carry everywhere with me in my backpack just in case. Which stays charged for well over a month. Of course, I use it more often than that.

 

A 2% 'droop' overnight is normal, I would say. Sometimes my Z33 does that, sometimes it doesn't. It definitely doesn't actually consume power when hibernated or turned off though.

I have noticed that standby seems to use more juice then I would expect it to.

 

Maybe yours doesn't, and maybe Rosemarycane's doesn't, but energy from my battery is being converted to heat while my laptop is entirely powered off.

 

Fact of the matter is, the battery is connected to the laptop and so long as it is connected to the laptop, there is always going to be a minimal amount of standby power used to activate some minimal circuits for things like checking to see if someone is pressing the ON button.

Unlike a light switch, the ON button on your laptop is not a toggle switch - it's a push-button switch with driver circuitry which basically turns on main power when someone pushes the button. Now whether that itself draws 2% overnight is disputable, it's likely that other parts of the system that need to be active on standby draw power as well.

If you think it's the battery, I would suggest removing the battery, and then putting it back on after to see if there was any loss. If there is some sort of major loss overnight (ie: > 20%), then I would think about going for RMA. But otherwise, it's like any other system running on batteries.

 

Ok. But if the computer is completely off, with the battery left in, and AC unplugged, it should not loose 2 percent overnight. I have had several laptops, and none have exhibited that behavior.

 

The 2% is probably within the margin of error of the measurement of the battery charge state, which I imagine is +/- 1%.

 

Or larger, or smaller than 1%.

I suggest (unsure whether I already did so?) not to worry about a 2% drop. Unless it's accompanied by other negative effects. E.g., the heat dissipation. That could mean that there is unwanted current (power) going through the laptop. That would suggest perhaps that there's something wrong with the laptop, and not the battery. I have never noticed laptops heating due to battery when they are off (although I never really checked).

 

Just wanted to give everyone an update (not like this is a hot topic or anything. lol)

I received the new battery from Asus. Faxed the paper work and had the battery the next day. Talk about fast service!!!

Anyway, popped it in the machine, calibrated the battery and everything seemed peachy keen. The battery light would come on for a couple seconds when the AC adapter was plugged in, then go out. Good so far.

Well today after leaving the computer plugged in and in hibernation, I shut it down and put it in my bag to go to work. When I got to work and plugged it back in, it was showing 1% of the charge gone.

Should I send the unit in to Asus for repair or not worry about it? What do you the forum members think?

 

The only time the battery will show 100% is when it's *at* the maximum charge. As I understand it, as soon as it decreases any amount down from that max (i.e. normal bootup, or whatever), the number will generally fall to 99% -- there is no rounding up, and the decimal is effectively dropped in the reported number, even though it's likely at 99.x%.

You're fine.

 

I posted about this same problem a few months back. The EXACT same thing is happening to my W3J. It seems to me that this isn't an uncommon issue, unfortunately.

 

It's not a freaking issue at all, it's perfectly normal. There is some error associated with measuring the charge state of the battery. It's maybe 1-2%.

In addition to the error in measuring charge, the SMBus circuit inside the battery itself that maintains the battery state information also uses a small amount of energy from the battery. You just replaced all that, though...

That's all you are seeing, *unless* you have a case like JPZ where it is losing 40% of the charge and a component is hot even when the laptop is off.