Like all modern vehicles with an internal combustion engine, your 2011 Chevrolet HHR requires a large, high-amperage battery, which is primarily intended to engage the engine's starter motor and provide constant power to the on-board computer systems, while allowing other electronic accessories to operate when the engine isn't running. Although it's typical for most passenger vehicles to house the battery under the hood, the battery for your HHR is located at the tail end.
Connect the memory saver device to the vehicle, according to the product's instructions. Open the rear hatch. Remove any items covering the rear cargo floor. Remove the carpeting from the cargo floor. Remove the storage compartment cover, then unscrew and remove the storage compartment's hold-down. Pull the compartment from the vehicle. The battery is located before the spare tire, on the passenger side.
Disconnect the black negative battery cable from the battery's “-” battery post, using a socket and ratchet. Disconnect the positive battery cable from the “+” battery post. Tuck the cables away from their respective battery posts. Put on a pair of acid-resistant gloves, then disconnect the vent tube from the side of the battery. Remove the battery.
Set the replacement battery into the battery compartment, then replace the hold-downs. Tighten the hold-down bolts to 18 foot-pounds, using a torque wrench. Connect the vent tube to the battery. Connect the positive battery cable to the battery, then tighten the terminal bolt to 11 foot-pounds; secure the negative battery cable and tighten the terminal bolt to the same torque specification.
Replace storage compartment, then tighten the hold-down. Replace the compartment cover, floor carpet and restore the contents to the rear cargo area. Disconnect the memory saver device to finish the battery replacement process.
