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How can i replace the cells of a laptop battery? Answered

I have an old beater laptop, who's battery will no longer hold a charge for more than a minute. How can i replace the cells in it so that it will work



9 years ago

Laptops haven't used lead-acid for many years, it is more likely NiCd, NiMH, or Li-Ion most likely. Considering your question, I recommend not attempting to replace Li-Ion cells yourself, a mistake can have dangerous, firey consequences. If the pack is so old that nobody sells a new version of it, see if you can find a site on the web that will rebuild old packs. Lastly, buying all the individual cells is often only a slight savings if any compared to buying the whole pack.

WARNING!!!! You can possibly burn up your motherboard out if the battery has a short in it or not assembled correctly.

very carefully take it apart, find what batteries you need...

Determine if the battery is lead acid or lithium ion. If it's lead acid, there's not much you can do. The lead acid batteries will be really heavy, lithium ion not so much.

Take the plastic case off the battery ONLY IF IT'S LITHIUM ION. Make a wiring diagram of the cells in the battery. Which cells are connected to which other cells and the orientation of the cells. Disconnect or desolder the old cells and replace with new cells of the same type and voltage (higher mAh is OK). Charge the battery fully before you use it. Be extremely careful when soldering or desoldering batteries! Too much heat for too long can cause the battery to explode, causing chemical burns, blindness and all kinds of nasty stuff. It's not my fault if this happens, you were warned.

If you're unlucky, they used a lithium ion battery of an odd size, like the giant flat ones. You can try finding a replacement for those, but replacing them should be easy.