Batteries.
AG13 batteries are used for watches and they are the small button shaped battery. Most of the time a jeweler will put them in if you purchase it in the store.
An oberlin technology store is Apple Campus Store that is approved to sell electronic devices. Oberlin technology store could also be used for recycling used lithium batteries, alkaline from any electronic device, such as digital cameras, cell phones, car batteries or laptops.
Batteries have energy because they use chemical reactions to store it within cells. The energy will slowly escape over time even when not used.
Most batteries used in watches are one and one half volts 1.5v]
Batteries are the most common ways of storing solar energy.
Solar panels do not produce electricity at night. You may be able to charge batteries during the day that you can use at night.
It is best to store a Lithium Ion better with a full or partial charge. If not used at all it is good to recharge it after a few months.
these are rechargeable batteries used in cell fones
Plutonium is not used in batteries.
Photovoltaic arrays are used( in conjunction with accumulators - batteries - to store energy when the satellite's solar panels are in shadow).
in inverter batteries