| Cover | Feb. 28, 2022 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 28, 2022 |
| Entity File Number | 001-40581 |
| Entity Registrant Name | FREYR Battery |
| Entity Central Index Key | 0001844224 |
| Entity Tax Identification Number | 00-0000000 |
| Entity Incorporation, State or Country Code | N4 |
| Entity Address, Address Line One | 412F, route D’Esch |
| Entity Address, City or Town | Luxembourg |
| Entity Address, Country | LU |
| Entity Address, Postal Zip Code | L-2086 |
| City Area Code | +352 |
| Local Phone Number | 46 61 11 3721 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Ordinary Shares, no par value | |
| Title of 12(b) Security | Ordinary Shares, no par value |
| Trading Symbol | FREY |
| Security Exchange Name | NYSE |
| Warrants, each whole warrant exercisable for one Ordinary Share for $11.50 per share | |
| Title of 12(b) Security | Warrants, each whole warrant exercisable for one Ordinary Share for $11.50 per share |
| Trading Symbol | FREY WS |
| Security Exchange Name | NYSE |
