Rebuilding Your Laptop’s Battery

Laptop batteries, like all other batteries, eventually die. Unfortunately, this usually happens before the rest of the computer dies of natural causes. For some people, who ordinarily use their laptops plugged in, it might not be too big a problem to have a battery that lasts for fifteen minutes. For others, who travel with their laptops regularly, however, this is a problem. The ordinary solution would simply be to buy another battery from the manufacturer. This is expensive, though! A new battery for my own laptop, I recently discovered, would set me back close to $180. It seemed to me that there might be a cheaper option.

There is. Instead of replacing the whole battery, it is possible to rebuild your battery, replacing the dead cells with new ones, at a fraction of the cost of a new battery. Before I explain this procedure, though, a few warnings. First, batteries contain dangerous chemicals and power expensive computers. Don’t go ahead with this unless you know what you are doing, and be aware that I am not responsible for anything that might happen.

Okay. That said, start by taking the offending battery out of your computer. Put it down on a flat surface, and find the seam that runs around it. Gently pry it open with a knife. This might take some doing. Remember, you are only taking the case off. Be careful not to puncture the cells inside. When you get the thing open, you will find a number of cells, (usually four or six, but as many as twelve) often held together by plastic. They will be connected in one manner or another to a circuit board, which will, in turn, be connected to the terminals that serve to connect the battery to your computer.

Before proceeding any further, look for some kind of serial or part number on the side of one of the cells. You’ll need this to find replacement batteries. Search for a replacement cells online. Try looking at www.allelectronics.com. Most likely, you’ll end up paying between $20 and $40 for a set of replacement cells. While you’re waiting for them to arrive, begin dismantling the old battery, very carefully. Most likely, the cells will be taped together, and fastened into their plastic casing with some kind of tape or glue. You’ll most likely find it rather frustrating trying to liberate them, but the persistent, and once again gentle.

At this point, you’ll probably be wondering how exactly the batteries are connected to the circuit board. “Why are there half a dozen wires?” you’ll ask. “Aren’t there supposed to be just two?” Good point. As it happens, the redundant wiring is designed to prevent short circuiting, and to decrease the chance that something could go wrong with your battery. If you can duplicate it, great, but otherwise, don’t worry about it. However, do note how the batteries are strung together. Series? Parallel? It’s very important that you find out.

Have the new batteries arrived yet? Good. Connect them together and up to the circuit board, following the exact configuration you saw when he took the whole thing a part. It’s possible that you’ll be able to get everything to connect properly simply by jimmying with it, but most likely you’ll need solder. Do so, make sure everything goes together properly, and close it all up. (Depending on just how difficult it was to get the battery open in the first place, tape may be required here) Charge it up and check it with it with a multimeter, if possible. It should work fine.

A good description of this process, complete with all of its theoretical underpinnings, is available at http://www.electronics-lab.com/articles/Li_Ion_reconstruct/index.html, in case you’re interested.

Sources:

http://www.allelectronics.comhttp://www.electronics-lab.com/articles/Li_Ion_reconstruct/index.html