5v Voltage on Battery

Not sure if I'm doing something wrong but the Arduino site says when powered by the LiPo the 5v terminal will see 4.2v from the battery as an output but that's not the behaviour I'm seeing. It seems to be showing about 1.6v on this terminal.

If I measure the voltage at the battery terminals at the same time I see 4.2v there and if I connect Vin or USB to a 5v supply I see 5v on the 5v pin as expected.

Any ideas?

Nick

For info in case others come up against this in future: I contacted tech support who said:

"When the board is powered from the battery the only available power output is 3.3V.
"The voltage you can read on the 5V and Vin pins is only a bias. You can't source a current from these pins when powered from battery.

"The only solution is to connect directly to the battery cable or using the test points on the bottom of the board."

Which is different to what the shop says about these boards. I have pointed that out in the hope that is corrected so others don't make the mistake I have done in future.

Nick