Batteries play a significant role in digital photography. For our Nikon flashes, we have chosen to use eneloop Rechargeable Batteries and Chargers (affiliate link) from Panasonic. We have found them to be reliable and hold their charge better than other batteries.

Video from Panasonic...

Here are the specs...

• Recharge up to 2,100 times
• Maintain up to 70% of their charge after 10 years (when not it use)
• 2000mAh type, 1900mAh min, Ni-MH pre-charged rechargeable battery
• 4 position charger with advanced, individual battery charging, AA and AAA cells
• Battery detection technology - automatically shuts off when charging is complete

Links to other gear recommendations...

• Cameras
• Lenses
• Accessories