CONCORD, N.H. (AP) — A 1911 photograph of Thomas Edison holding an alkaline battery with his penned declaration about the invention’s importance in transportation has sold for more than $ 31,000, believed to be a record for a signed Edison photo.

RR Auction of Amherst, N.H., said the photograph was sold Wednesday night in an online auction for $31,554. Its estimated value was $5,000.

“I believe time will prove that the Alkaline Storage battery will produce important changes in our present transportation systems,” Edison wrote underneath the photo.

Bobby Livingston, the company’s vice president of sales and marketing, said the signature, the statement’s content and the photo’s excellent condition accounted for the high bid.

“He has that famous signature with what we call the ‘umbrella T’ and this one he signed here is just so incredibly beautiful,” Livingston said.

The photo was the property of Walter Holland, who worked with Edison on the battery and published his lab reports on the project. Holland was appointed chief electrical engineer of the Edison Storage Battery Company in West Orange, N.J., in January 1911. The photo is dated May 4 of that year.

“The association between the two is really strong,” Livingston said.

Edison started his work on the alkaline battery in the 1890s, just after the motorcar had been introduced. His initial inspiration was creating a better battery to power an electric vehicle that was more lightweight and efficient than conventional lead-acid storage batteries at the time.

About 50,000 experiments later, he produced a nickeliron alkaline battery in 1910. But by then, technology had improved for cars run by gasoline and electric vehicles were not as popular.