(Reuters) - Investigators searching for the cause of a fire on a Boeing Co (>> The Boeing Company) Dreamliner in London last week are looking at the battery in an emergency locator transmitter built by Honeywell International Inc (>> Honeywell International Inc.), a source familiar with the probe told Reuters on Monday.

That device is powered by a lithium manganese battery, a long-life battery that has been around for decades and used widely in the military as well as products like digital cameras, walkie-talkies and pacemakers.

The following are some facts about these batteries:

- Lithium manganese dioxide batteries (LiMnO2) are disposable, or "primary" batteries, that have a shelf life of 10 years or more. They offer double the voltage and last at least two times longer than cheaper alkaline counterparts.

- They should not be confused with lithium-ion batteries, a powerful family of rechargeable batteries. These devices are used widely in smart phones, electric cars and in other parts of the Dreamliner. In its Chevrolet Volt plug-in hybrid, General Motors Co (>> General Motors Company) uses a lithium-ion battery with a manganese chemistry.

- Lithium manganese battery cells come in a number of shapes, including the cylindrical form often used in consumer products.

- About half of each cell is made up of manganese dioxide while lithium accounts for 3 to 4 percent, according to a fact sheet from Saft Groupe (>> SAFT) dated November 2012.

- Other makers of lithium manganese batteries include Ultralife (>> Ultralife Corp.), identified by a source as the supplier to Honeywell, Sony (>> SONY CORPORATION), Panasonic (>> Panasonic Corporation) and Eagle Picher (>> Eagle-Picher Industries).

(Reporting by Deepa Seetharaman; Editing by Tim Dobbyn)