SYDNEY, Jan 3 (Reuters) - Chinese base metals were mixed in early trade on Wednesday, as the most active copper contract slipped, while lead gained the sharpest as parts of the United States braced for more frigid weather. The peak demand period for lead, which is largely used to make batteries, is during winters when the freezing weather causes battery failures. Commodities traders said mixed signals were also emerging over the extent of China's demand for imported industrial metals in 2018, which was dampening activity among some local investors. Optimism about Chinese demand was boosted overnight by an unexpected December rise in manufacturing and a pick up in new orders. But higher prices for raw materials and firms cutting staff have fuelled concerns about growth. However, Goldman Sachs said it sees more risks to the upside than the downside for metals demand in China, playing down concerns of a sharp decline from policy changes. FUNDAMENTALS: * Three-month copper on the London Metal Exchange was down 0.2 percent at $7,187.50 a tonne, by 0123 GMT, extending losses from the previous session. * The most-traded copper contract on the Shanghai Futures Exchange slipped 0.4 percent to 55,920 yuan ($8,615.01) a tonne. * SHFE LEAD: ShFE lead was the top gainer on the exchange, rising more than 1 percent at the start of trade, while zinc gained a modest 0.6 percent, failing to build on a significant move in the LME contract overnight to a 10-year price peak on expectations of supply deficit. Lead was aided by forecasts for further cold weather in the eastern United States, which could lead to greater demand for replacement lead batteries in automobiles, a key market for the metal. * COLD FREEZE: A record-shattering freeze kept its grip on much of the eastern United States on Tuesday, causing at least seven deaths and closing schools as forecasters warned of a storm that could slam some areas with blizzard conditions later this week.