Complex sentence: Rechargeable alkaline batteries have the ability to carry their charge for years, unlike NiCd and NiMH batteries discharge in 90 days and, if produced properly, are an environmentally friendly form of energy storage.
Split into simpler sentences: Rechargeable alkaline batteries have the ability to carry their charge for years, unlike NiCd and NiMH batteries which self-discharge in 90 days. If produced properly, rechargeable alkaline batteries are an environmentally friendly form of energy storage.