EBL 600mAh 9 Volt Li-ion Rechargeable 9V Batteries Lithium-ion, 8 Pack Battery: 8 pack 6F22 9V 600mAh lithium-ion rechargeable battery No memory effect,can be charged anytime Improved low self discharge makes it still maintain 75% of capacity after 3 year of non-use Batteries come pre-charged and can be recharged up to 1200 times Recommended for smoke alarms, professional audio and medical devices