A little battery like 6ah sla will work to operate locks but I wasn't able to work my locks when i had my jump pack attached under the hood when i had my battery out of the car might need baby battery in the trunk.

When i pulled my battery for charging i just left my back seat down so i can climb back and use emergency release to open trunk.

Just be sure not to leave the floor propoed up.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)