The main benefit of batteries is that they increase convenience for users since they enable portability of devices. Their biggest disadvantage is that they can only be used for a limited time. Even rechargeable batteries eventually die.
Batteries come in various types including general purpose, alkaline, mercury and lithium, the newest and most advanced type.
Most batteries do not need to be connected to an external electrical system, and this is a practical advantage in specific cases such as in cars, aircraft and many other portable devices that require power. Batteries can be used in places with no electrical supply such as remote rural areas. In such cases, batteries play a critical role in sustaining livelihoods. Another major advantage is that batteries are easy to replace once they go beyond their useful lifespan.
On the downside, some batteries require maintenance and need to be checked periodically. Certain batteries are highly dangerous as they can explode, cause fire and lead to chemical pollution.
Rechargeable batteries take time to recharge, and this can be a big hindrance in case of an emergency.
In case of larger equipment, batteries can increase their weight, and this is a disadvantage when there is need to transport the equipment.