Is 16.8V safe enough for Juma PA-100D?

[BH4DKR]

The manual said Max. supply voltage do not exceed 16V.

I have a battery pack (4s 21700 battery), the max voltage is 16.8V when fully charged.

Is 16.8V safe enough for Juma PA-100D ?

[BH4DKR]

I checked the schematic of PA-100D, it looks like not safe enough if the power supply is 16.8V. Maybe it will work for a while, but not safe.