Battery Relocation Tray: 9th Gen Civic Si Install Tips

By ACUITY Instruments: Performance Automotive Products | Published: 2026-10-31

Category: How-to Guides

Step-by-step guide to installing a battery relocation tray on a 9th Gen Civic Si, with practical tips to avoid common mistakes.

Quick Answer

Installing a battery relocation tray on a 9th Gen Civic Si frees up engine bay space for intake piping. Focus on secure mounting, cable routing, and corrosion protection for a reliable setup.

Why Relocate the Battery on a 9th Gen Civic Si?

The 9th Gen Civic Si engine bay is tight, especially with a cold air intake or turbo piping. Moving the battery above the transmission clears space for larger intakes and simplifies routing. The tray bolts to the transmission mount, using existing hardware so you don't have to drill into the chassis.

Trade-Offs Before You Start

Relocating the battery adds weight higher in the engine bay and requires running a heavy-gauge cable from the battery to the starter. The stock battery hold-down won't work, so use a proper relocation tray with a secure clamping mechanism. Also, you'll need to extend or reroute the main battery cable.

Installation Steps

Disconnect and Remove the Battery: Disconnect the negative terminal first, then the positive. Remove the battery hold-down bracket and lift the battery out. Remove the factory battery tray if it's in the way. Always disconnect the negative terminal first to avoid shorting tools against the chassis.
Mount the Relocation Tray: Position the tray above the transmission. Align the mounting holes with the transmission mount bolts. Use the supplied hardware to secure the tray; tighten to the torque specified in the instructions. Confirm the tray sits level and doesn't contact the shift cables. Check for clearance with the shift cables and intake before tightening fully.
Route the Battery Cable: Run a positive battery cable from the tray's terminal to the starter solenoid. Use grommets where the cable passes through metal. Keep the cable away from exhaust heat and sharp edges. Connect the ground strap from the tray's ground point to the chassis or engine block. Crimp and heat-shrink all terminals to prevent corrosion and voltage drop.
Secure the Battery and Wire: Place the battery into the tray grooves and tighten the hold-down bracket. Use zip ties or a cable clamp to secure the positive cable along a safe path. Reconnect the negative terminal to the tray's ground point. Double-check that the battery cannot shift during hard cornering—use the provided rubber pad if included.
Test and Final Inspection: Reconnect the positive cable at the battery. Turn the key to the ON position (engine off) and verify electrical systems work. Start the engine and check for any rubbing, loose connections, or fault codes. If the car doesn't start, check the main fuse and verify the ground connection is clean and tight.

Product That Helps

Battery Relocation Tray for the 9th Gen Civic Si: This tray is made from a rigid stainless steel lower frame and an anodized aluminum upper tray, riveted together. It mounts rigidly to the transmission mount and includes a ground connection point on the tray frame. The dual-material construction resists corrosion and vibration, while the integrated ground point simplifies wiring and keeps the engine bay clean.
Battery Relocation Tray for the 9th Gen Civic Si