Strange request to save a real mac

First of all, I hope my exotic english will be clear for you.
And I hope that I am at the proper place for my request.

I have a strange request, but my idea could possibly save a mac.

My neighbor "killed" his Macbook Pro 15' Mid 2010.
He used his mac on battery with a large number of connected devices until the battery went completely empty. Not one time. A very large number of times. Result 1 : a totaly empty battery which has certainly died. Result 2 : no more boot. Result 3 : a certainly dead SMC (no reaction even after resetting the SMC with keyboard).

But I can boot the mac with this emergency procedure:
I press shift + Ctrl + Alt + Start button for 5 seconds and then release the keys but not the start button. I wait for 5 sec more with my finger on the power button and when I leave it : the MBP starts with fan out loud, no battery, no backlight, no clock and other jokes. It's not really possible to use it like that.

I updated the smc firmware, which had not been done before and it succeeded. But no improvement at the boot.
I booted via rEFIt to try to downgrade the SMC. But simply reseting the SMC turned the mac off. Many times. I did not go further.

Now I tell myself that even with a weird boot process on the keyboard (see above) and without a battery, there may be a way to use the mac in better conditions than with fans out loud and everything else.
With FakeSMC. And may be another kext like NullCPUPowerManagement ?

If it works on a PC, there's no reason why it would'nt work on a mac.
Except I do not know how to do it properly.
I do not know where you place FakeSMC (S/L/E or EFI partition ?) nor which version of FakeSMC to choose (knowing that the mac is under Mavericks), or where to get it.

If you can help me a little, that would be nice.

Thank you in advance.

FakeSMC won't make the fans behave because they're still controlled by the SMC, regardless of what kexts you give OS X to play with.

If the SMC is dead as you suspect the only solution is to replace the SMC with one from a donor board.

If you aren't sure if the SMC is the true culprit definitely check this video by Louis Rossmann where he goes over it:

He's also got a video on replacing the SMC chip itself but it's a bit long winded.