Ok, I'm sure I will need to replace either my battery or my AC adapter, but would rather not buy one if the other is the problem.

My problem is. I have a Sager laptop that gets quite a bit of use. The charging has always been a little bit odd. If I was in the process of using it, it would charge just fine and stay On AC power. If I left it alone, however(power settings to ONLY turn off the monitor) in either Ubuntu or Windows 7 it decides that it didn't want to use AC power anymore and would just start draining the battery until it died.

Now, suddenly, it won't charge at all. The capacity was great up to this point which happened in an instant. It will recognize the battery but won't see the AC power if plugged in while the battery is in. I can power up the laptop without the battery and it works fine. If I plug in the battery while powered up it will claim it's charging it, but it stays at the same percentage. If I unplug the power, it will switch over to Battery fine, but I have to power down and unplug the battery to get it back on AC power.

I've had dying/dead batteries before but they typically won't hold a full charge anymore but it still winds up to 100% then drops quickly when unplugged. This seems more like a chip problem in the battery to me, but I'm not sure.

Any ideas?


I'm not familiar with this manufacturer at all, but I agree that this could be a problem with the battery gauge. Look in the OEM's power management software and see if there is someway to do a gauge reset or calibration or maintenance cycle or something to that effect.

This could also be the charging mechanism on the laptop itself - the easiest way to see that is to try another battery. (If it does this with any battery you're probably looking at a motherboard replacement; that stuff is usually integrated.) Veeery slim chance that it might be the actual power connector for the adapter but that's incredibly unlikely.

  • My biggest concern is if it's a system board issue itself. I've disassembled the battery and don't see any signs of overheating or any obvious signs of chip damage either. You'd say it's probably not the AC adapter though? – Jeff F. Jan 5 '11 at 19:11
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    @Jeff - If it works fine with the battery removed, I don't think it's the adapter. – Shinrai Jan 5 '11 at 19:12
  • Thanks, I was thinking the same thing, but I've heard elsewhere that the AC adapter can be damaged, but still power a laptop. Seemed bogus to me. – Jeff F. Jan 5 '11 at 19:38
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    @Jeff - No, it is possible, it's just so unlikely that I'd only look at it after ruling out the other (easily done) stuff. I mean, if you can get ahold of another adapter easily, go for it. – Shinrai Jan 5 '11 at 21:24
  • I got a new battery, it's not charging either... I'll post a new question if I need further info. – Jeff F. Jan 6 '11 at 15:37

This may sound as a left field answer, but it really works. I have found on many occasions, when laptops were not charging correctly, or acting really funny, that I have been able to solve the issues with less than $10 - $15.

The first and most common solution is the CMOS battery. Believe it or not, a dead or dying CMOS batter can cause serious issues with the charging functionality of the laptop. I would recommend Googling your laptop along with "CMOS replacement." And the replacement batteries can be found at most office supply or hardware store. I get mine on EBAY for super cheap.

It can be a headache to get to on a laptop, but if you can fix your problem for under $2, you are golden.

The second and most common scenario that I have found similar to your case is where the power module on the laptop itself is shot. This is what the power adapter plugs into. I have found (most commonly in DELLs and HPs) that this piece isn't soldered to the mobo, it just clips in. Buying the replacement module can be as cheap as 5 and as much as 15 bucks. Some cost much much more.

If this is the case, it can also be a real pain to replace, but I assure you, if it works, you will be happy. A simple google search of your laptop model will let you know how hard either task is.

EDIT: To go into a bit more detail as to why these work.... It seems that power is passing through from the AC adapter, but the biggest issue is how and where it is being diverted. Both replacement parts will affect how power flows in the laptop. Try the cheapest first.

  • If the laptop is keeping correct time when removed from power (disconnect from AC and also remove the battery), there's nothing wrong with the CMOS battery. – Jamie Hanrahan Feb 3 '18 at 8:29

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