A comment just for fun.
Neither here nor there producing any tips, I took a wood chisel to my Sony battery – by pure chance, on the non technical edge. The other edge had a PCB with over 100 components on it!! And at least 4 of these was LSI. What are they thinking????!!!!!
I found that two of the cells were totally open, and they look pretty well made so replacing them is not lightly to be cheap, (great success with my shaver, but this is a new ball game.) and the firmware might not let them perform even if i did the job. It's $ 109 for a replacement clone, and the computer cost me zilch 6 years ago cos Sony wanted 1,300 pounds sterling for a part when the whole computer had only cost 999.
The guy in Brussels told me that they look for fingerprints inside as soon as it arrives for repair, and the guarantee is all over if they find any. My pal claimed on his insurance and i got a free if defunct 3 month old unit.
Sony's reply gave me a bloody-minded determination to mend it, so i did some micro surgery on the (maliciously prodded) PCB, pumped up the BIOS Batt and away it went. I've used it almost every day since. Can't give in now.