Exide Battery Shares Slump to 6-Month Low  CHICAGO (Reuters) - Shares of Exide Technologies &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=XIDE.O target=/stocks/quickinfo/fullquote"&gt;XIDE.O&lt;/A&gt;  slumped to a six-month low on Tuesday, a day after the lead  battery maker posted a wider quarterly loss due to dramatically  higher lead prices.