Tip & How-To about Computers & Internet

Troubleshooting Laptop Power Failures - The Battery

Symptom:

Battery does not charge while the laptop is plugged.


Diagnosis & Solution:

First thing is to make sure that there is AC power to the adapter. Some AC adapters have an indicator LED which glows when they are receiveing power from wall outlets. If your AC adapter does not have one, then make sure that the cord from the wall outlet to the AC adapter is firmly plugged into the AC adapter. Also make sure that the AC adapter is plugged into an operational wall outlet. You could also check the laptop's power indicator LED to verify whether it is receiving AC power from the wall outlet or not.

Next thing is to make sure that the AC adapter's connector tip is fully plugged into the power receptacle in the laptop. If this did not help, then the next step is to check & confirm that the AC adapter itself or the cable connecting it to the laptop has not failed. You can easily verify this by using a digital multimeter set to measure DC voltage. Use the digital multimeter's probes to measure the output voltage from the connector at the end of the adapter's cord to the laptop. Compare the reading you get to the nominal DC voltage required by the laptop, which you could find written on a label stick to the bottom of the laptop. The output DC voltage from the AC adapter should not read significantly less than the nominal DC voltage required by the laptop. If you find no or a significantly low output DC voltage from the AC adapter, then you will have to replace this AC adapter with a new one.

It is also necessary to make sure your AC adapter is providing enough power to both run the laptop & charge the battery. A very good way to do this is to compare your laptop voltage & ampere requirements (written on a sticker on the bottom of the laptop) with the voltage & ampere ratings of the AC adapter. Voltages should be the same, or the AC adapter's voltage about up to 0.5 volts more than the laptop's voltage rating. Amperage of the AC adapter should be at least equal to or greater than the laptop's rating. It should never be less than the laptop's rating, or else the AC adapter will be providing insufficient amperes to charge the battery. Of course, the AC adapter's nominal amperage might be OK, but it degraded on usage. You can verify this by using a good or new AC adapter, or by testing your laptop's AC adapter with another laptop.

If the previous tests confirmed that everything is OK so far but your laptop's battery is still not charging when the laptop is plugged, then there might be a possibility that the battery is not making good contact with the laptop's charging circuitry. To eliminate this possibility as a root cause of the battery not charging, turn off and unplug the laptop, take the battery off the laptop, and using a dry tooth brush, scrub in between the fins of the battery connector on the motherboard & on the battery it self. When done, put the battery back into the laptop, plug it, and turn it on. Check if the battery starts charging or not.

What if after all this the battery is still not charging? Well, we might then start to suspect that the battery itself is bad. This could be verified either by testing the battery in a similar laptop, or by swapping the battery with a new one or one which is known to be in a good working condition. If your battery does not charge when tested in the other laptop, then it is obvious that the battery is bad and has to be replaced. However, if your battery starts charging in the other laptop, then we are left with a couple possibilities: your laptop needs a BIOS update, or your laptop's charging circuitry is defective.

When laptop owners call tech support to report that their battery isn't charging or the life doesn't seem to be what it should, tech support will often tell them to download the latest BIOS. While it's marginally possible that the laptop shipped with a BIOS that has been improved in regards to battery management, the BIOS upgrade process, called flashing, is not reversible without special equipment. In other words, if something goes wrong, instead of having a laptop with a battery charging problem you'll have a collection of perfectly good laptop parts that won't do anything. Flashing the BIOS is a last resort we only recommend if you find references on the Internet that it fixed an identical charging problem for somebody else with your exact model.

If at last it turns out to be a defective charging circuitry, then you will definitely need to disassemble your laptop in order to gain access to its motherboard. The motherboard should then be checked for any burnt out components in the area surrounding the power receptacle. Burnt out components will need to be replaced, or if not possible, the motherboard will have to be replaced.

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M. Omran

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1 Answer

My battery do not keep any charge, but its condition was diagnosticated as "excellent" with specialized programs. The laptop works only with an automatic multi adaptor (Woxter brand). The system reports the battery as "0% and charging".


"plugged in, not charging" could a symptom of incompatibility between the charger and the battery.
If this is the case, once you unplug your ASUS ac adapter, the laptop goes off.
Anyway, it's still Ok to use the charger but you need to plug it in all the time.
Here is a little trick that I found that works.
1. Power up the Notebook with the battery installed,if you can.
2. Turn the computer completely off and remove the battery.
3. Power up the Notebook with AC power only (no battery installed).
4. Turn the computer completely off and re-install the battery.
5. Power up the Notebook.
6. The message no longer appears (at least for me it has disappeared).

Aug 12, 2013 | ASUS Eee PC T101MT-EU27-BK Convertible...

1 Answer

when plugged in, will not turn on.sylvania synetlp7" 2gb tablet


"plugged in, not charging" could a symptom of incompatibility between the charger and the battery.
If this is the case, once you unplug your charger, the laptop goes off.
Anyway, it's still Ok to use the ac adapter but you need to plug it in all the time.
Here is a little trick that I found that works.
1. Power up the Notebook with the battery installed,if you can.
2. Turn the computer completely off and remove the battery.
3. Power up the Notebook with AC power only (no battery installed).
4. Turn the computer completely off and re-install the battery.
5. Power up the Notebook.
6. The message no longer appears (at least for me it has disappeared).

Aug 07, 2013 | Computers & Internet

1 Answer

no power from battery to laptop


are you installing it with correct polarity
is one of the battery terminals in the laptop damaged so that it is not making contact

May 22, 2017 | Acer Computers & Internet

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