noun which may take the genitive case particle 'no', noun
rechargeable
Describes devices or batteries that can be recharged. Often used as a modifier before nouns (e.g., 充電式バッテリー).
この掃除機は充電式です。
This vacuum cleaner is rechargeable.
充電式の電池を買った。
I bought rechargeable batteries.
充電 is the noun/verb 'charging', while 充電式 is the adjective meaning 'rechargeable'.
Compound of 充電 (charging) + 式 (type/style), literally 'charging-type'.