Car Battery

Car Battery is a passive item added in Afterbirth.

Effect

Blank Card + Rune of Algiz: Doubles the shield duration to 60 seconds.
Crooked Penny: Splits the 50% chance to succeed into a 25% chance to quadruple all items and a 25% chance to duplicate all items while consuming the originals; the latter will make devil deal and shop items free.
Guppy's Head: Doubles the amount of flies spawned.
The Pinking Shears: Spawns 2 headless bodies.
Void: Doubles effects of all absorbed activated items.

Book of Secrets: Activates twice, but has a chance to uselessly activate the same effect twice.
The D6/D8/D12/D20: Re-rolls twice instantly without any benefits. D6 depletes item pools at double the speed.
D4/D100: Instantly re-rolls Isaac's items twice, which doubles the speed at which the item pools are exhausted and transformations are achieved.
Dead Sea Scrolls: Activates 2 random effects.
Mine Crafter: Spawns a barrel and instantly detonates it, damaging Isaac.
- This has been changed to spawn two Barrels instead, which you can detonate at will.
Moving Box: Activation swaps the contents of the box with the contents of the room.
Ventricle Razor: Places both trapdoors in same location.

Extension Cord - Have The Battery, 9 Volt, and Car Battery in Isaac's collection.

Jumper Cables - Pick up any 2 of the following items/trinkets in a single run: 9 Volt, The Battery, Car Battery, AAA Battery, and Watch Battery ( Any 2 items that have the 'battery' item tag).