How to Test Your Laptop’s Battery

Laptop batteries can fail, or over time can lose their ability to hold a charge. If your laptop suddenly stops cooperating, you can usually determine if a bad battery is causing the problem by removing it from its bay (on the bottom or side of the laptop) and running the laptop from the AC adapter only. If the batteryless laptop runs properly when connected to the adapter, the battery has most likely kicked the bucket, shuffled off its mortal coil, and otherwise become defunct.

You can further test this hypothesis by substituting a battery that you know is functioning well from another laptop of the same model. You may be able to borrow a coworker’s battery or take the laptop to a cooperative retailer’s repair counter.

If, in the other hand, your batteryless laptop doesn’t run when connected to the AC adapter, either the adapter or the laptop’s internal electronics have failed. Again, if you can borrow a known-good adapter, use it to see if the problem is caused by the cords or converter or if the issue lies deeper within the laptop itself.

Comments (1)

  1. Posted by James Moorcroft
    Depending on the laptop make/model this may not work. Some laptop's will not work without the battery being fitted, as they are designed as a serial powered unit (the electricity has to run around the full circle, including the battery, to work). Others do not have to have the battery fitted as the electrical current is in a parrellel system (it has many routes it may take not just the one in a cirle). I strongley suggest you check with manufacturer to see which way your laptop works before buying new battery, which can be very expensive. JM