| Cover | Mar. 20, 2024 |
| Document Information [Line Items] | |
| Document Period End Date | Mar. 20, 2024 |
| Entity Registrant Name | FREYR Battery, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 333-274434 |
| Entity Tax Identification Number | 93-3205861 |
| Entity Address, Address Line One | 6&8 East Court Square, Suite 300 |
| Entity Address, City or Town | Newnan |
| Entity Address, State or Province | GA |
| Entity Address, Postal Zip Code | 30263 |
| City Area Code | (678) |
| Local Phone Number | 632-3112 |
| Document Type | 8-K |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001992243 |
| Amendment Flag | false |
| OrdinarySharesWithoutNominalValueMember | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | FREY |
| Security Exchange Name | NYSE |
| WarrantsEachWholeWarrantExercisableForOneOrdinaryShareAtAnExercisePriceOf1150Member | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Warrants, each whole warrant exercisable for one share of Common Stock at an exercise price of $11.50 |
| Trading Symbol | FREY WS |
| Security Exchange Name | NYSE |
