Examples (the non-parenthetical representation is a string used to construct the BigDecimal):
"large_float": 1.7976931348623157e308 (BigDecimal: 17976931348623157e+292)
"small_float": 4.9406564584124654e-324 (BigDecimal: 4.9406564584124654E-324)
I looked through the source for the formatting and it appears "e" is the majority case but existing test cases check for "E" in a couple places.