Iso-Tip 7987 is a 3.2V, 3500 mAh Li-ion rechargeable battery. It is a cylindrical cell with a diameter of 18.5mm, a length of 65mm, and a weight of 40g. It has a maximum charging voltage of 4.2V, a discharge cut-off voltage of 2.5V, and an operating temperature range of 0°C - 40°C. It has a maximum continuous discharge current of 1C and can be charged at a rate of up to 1C. It features built-in protections against overcharge, overdischarge, and short-circuit, and can store up to 70% of its capacity after 1 year of storage.