U.S. Army Sgt. Bowe Bergdahl has released his first account of the torture he says he endured during the five years he spent in Taliban captivity, just hours after authorities announced that he will face charges for desertion and misbehavior before the enemy, which carry a possible life sentence.

The account was released by Bergdahl's attorney, Eugene Fidell, who released a statement to the media Wednesday that hinted at how the soldier's defense might be conducted.

Bergdahl's letter begins: “In the beginning of my captivity, after my first two escape attempts, for about three months I was chained to a bed spread eagle and blindfolded," according to a transcription from KBOI.

"During these months some of the things they did was beat the bottoms of my feet and parts of my body with a copper cable. After the first three months they moved me. Though they never fully chained me to a bed again, the first year I spent in chains on both hands and feet, and more often then not, even in the locked room, they had my feet chained to a solid unmovable abject [sic] either outside or inside the room."

He goes on to describe being transferred to a cage after about a year of captivity, where his hands and feet were shackled. He describes “acute pain,” swelling and numbness in his limbs as a result of this confinement, as well as having between 8 to 12 open wounds on each wrist where his hands were fettered.

In addition to his confinement and frequent beatings, Bergdahl claims he was told repeatedly that he was going to be executed, and made to watch Taliban videos.

"I was kept in constant isolation during the entire five years, with little to no understanding of time, through periods of constant darkness, periods of constant light, and periods of completely random flickering of light and absolutely no understanding of anything that was happening beyond the door I was held behind," he writes.

He also outlines his frequent attempts at escape. He writes that he made approximately 12 bids for freedom, but was recaptured after each attempt, after periods on the run ranging from 15 minutes to nine days.

The letter sent by Bergdahl's lawyer, which accompanied his account, said: "In light of the nearly five years of harsh captivity Sgt. Bergdahl endured, the purpose of his leaving his unit, and his behavior while a prisoner, it would be unduly harsh to impose on him the lifetime stigma of a court-martial conviction or an other than honorable discharge and to deny him veterans benefits," Fidell wrote.

CNN Pentagon correspondent Barbara Starr said that the document represented Fidell laying out the case he will attempt to make when the case goes to trial. The document does not address the issue of why Bergdahl left his base, but suggests that the reasons for his action will come out during proceedings.

Bergdahl disappeared from his base in eastern Afghanistan in June 2009, where he was serving with the Army's 501st Infantry Regiment, and subsequently taken prisoner by the Taliban-aligned Haqqani network.

He was exchanged for five Taliban detainees, who had been held at the U.S. detention facility in Guantanamo Bay, Cuba. The released detainees were sent to Qatar.