Discharge and safety characteristics of improved low magnetic signature lithium cells

A family of non-magnetic cells has been developed by Wilson Greatbatch Ltd. (WGL) for use in equipment that is sensitive to magnetic interference. These cells power devices for acoustic mapping of the ocean floor, recording current meters, and downhole tools used in directional drilling equipment. While their magnetic signature was reduced by a factor of 15 over the standard cells, it was too large for use in the stringent environments of a magnetic resonance imaging (MRI) suite. A new series of low magnetic signature (LMS) cells has been developed for more demanding environments. Their magnetic signature was reduced by a factor of 12 over the original non-magnetic design. BCX cells in low magnetic signature (BCX-LMS) configurations were evaluated under a series of performance and safety tests. BCX-LMS cells exhibit energy densities greater than 400 Wh kg−1 at room temperature. Safety tests show that these cells conform with the UN Recommendations for the Transport of Dangerous Goods, Manual of Tests and Criteria T-1 and T-2. Visual examination of the cells after the tests showed no evidence of leakage, venting or case distortion.