Can I fix the battery if damaged

@amos33666 unless you have done this before, I would suggest you replace the battery.

Now, if you want to give it a try, you will actually have to open the hard plastic case. You should find multiple different cells (possibly 18650 Lithium cells) You would need to replace those. Now, you do need to pay close attention on how they are connected to each other. They will be in series and parallel. Make sure that you either keep a diagram or some good photos. You will also find a Battery controller. That is a very important part so take good care of that. De-solder it and put it aside until later use.

Next replace the cells and solder the Nickel strips between the replacement cells the same way as they were connected in the original. Last, replace the battery controller. Now, one thing I've learned is that it is so much easier and cleaner (and most certainly proper) to use a spot welder to attach the Nickel strips. Even spomething like this (example only, not an endorsement) will work. Otherwise you will have to use a soldering iron which can be a PITA.

Hardest part will be to crack the original case open :-) Use a sharp knife to cut along the seems around the case to open it. Careful when you pry it open so as not to break the plastic.

Post some good images of your battery and even when you have it opened, with your Question. that way we can see what you see and hopefully guide you further and more specific to your battery.

Adding images to an existing question

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