[1/3] Tesla's new electric semi truck is unveiled during a presentation in Hawthorne, California, U.S., November 16, 2017. REUTERS/Alexandria Sage/File Photo/File PhotoSan Francisco, April 6 (Reuters) - Tesla Inc (TSLA.O) said it plans to expand the use of cheaper, iron-based batteries to a version of its Semi heavy electric trucks and an affordable electric vehicle. Tesla last December started to deliver its Semi electric trucks with a longer, 500-mile driving range per charge and which use nickel-based batteries. Currently, Tesla uses nickel-based batteries for most of its Model 3 and Model Y vehicles sold in the United States. Tesla's South Korean supplier, LG Energy Solution (373220.KS), said it plans to build LFP batteries at its proposed Arizona factory.

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