Leaf Spy Lite lets a Nissan Leaf owner view detailed information about their Leaf's battery by plugging in an inexpensive ELM-327 Bluetooth OBDII adapter into the standard OBDII port on the Leaf. ELM-327 Bluetooth adapters are available on eBay for around $10-$20 and one is required before Leaf Spy Lite can display information from your Leaf.