I just tried to find anything out by myself
as far as i see it they sel things via codejunkies.com
there is no faq for the TOOL battery, the forum is closed
there is no closer description of the Battery but:
Special TOOL version of our MAX Power PSP Battery designed for use in original PSPs (not the new slimline model).
- Special TOOL version of our PSP battery works in exactly the same way as a standard SONY PSP battery but has the ability to put your PSP into service mode for custom firmware use.
- TOOL functionality is hard-coded into the battery.
- 1800mAh Lithium Polymer cell for use in original PSP consoles
Please note: The TOOL functionality is hard-coded into this battery to put the PSP into service mode. This functionality cannot be disabled.
Which is deciving because
a.) the Service mode does not enable Homebrew. -.-
b.) you cant use it normal daily use because you cant disable the Service mode
(each coldboot brings you to a black screen without a Memmorystick with a custom IPL and Boot menu)
c.) They dont give any hint how to do any of those things...