The S2 has a battery box under the left passenger seat. The battery can be left in it's stock location (like the Treadway car), but
1) it is a very hot spot for a battery to live;
2) It makes an already tight engine compartment even worse;
3) relocating the battery is an appealing weight distribution upgrade.
Either put it in the back compartment (Contact Rick Zehr) or buy the S2 battery box and weld it in. [Battery box is $200] Note that removal of stock battery box can be cheap or expensive. Mine was ludicrously thorough, using body filler and full three step pearl paint to make it appear factory. Budget alternative?  Use a Sawzall, a file and some spray paint to achieve the same thing.  Somewhat to my surprise, we never really used this space for anything, but it is a real luxury to have the engine bay access.
 
 
 
    Parts required if you decide to relocate the battery:
 
 

Battery box

895 803 901

Notice you need a new high pressure fuel line to circumvent the box.  We used flexible aeroquip. George also exchanged the fuel filter mounting bracket with onefrom an urq, although this couldíve been modified or fabricated also.
 

Battery Box support part	895 825 217	Plastic piece extends forward of box as a kind of skid plate for the fuel filter
Grommet	311 611 835	2x
Plug	811 603 583C	2x
Fuel line	295 201 545	Optional, could use Aeroquip.