Energizer Battery Max 522 9 Volt 2 pack^{^} (always read the label)

Storage: Store in a cool, well ventilated area. Elevated temperatures can result in shortened battery life. Mechanical Containment: Designers of any water or air-tight device should be aware of the normal evolution of hydrogen gas from alkaline batteries. This gas must be either absorbed or allowed to escape to avoid a potential safety issue. Handling: Accidental short circuit for a few seconds will not seriously affect the battery. Prolonged short circuit will cause the battery to lose energy through heating, and can cause the safety release vent to open. Sources of short circuits include jumbled batteries in bulk containers, metal jewelry, metal covered tables or metal belts used for assembly of batteries into devices. Soldering directly to a battery is not recommended. If welding to the battery is required, consult your Energizer sales representative for proper precautions to prevent seal damage or short circuit. Charging: This battery is manufactured in a charged state. It is not designed for recharging. Recharging can cause battery leakage or, in some cases, high pressure rupture. Inadvertent charging can occur if a battery is installed backwards. Labeling: The label acts as an electrical insulation for the battery can. Damage to the label can increase the potential for a short circuit. WARNING: Do not install backwards, charge, put in fire, or mix with other battery types as it may explode or leak causing injury. Replace all batteries at the same time.

Zinc-Manganese Dioxide (Zn/MnO2)