electrical issues

[TS1-200]

Having problems powering sat nav. currently power my sat nav via a usb port direct from a 12v battery charged from a 12vdc feed from a regulator, however The USB port regularly fails tried different types with varying degrees of success, the regulator delivers spikes of around 16v when engine revved, I have tried different regulators and they all do the same, do I need a device between the battery and usb port to even out the voltage to around 12v, is there such a thing.
it is annoying, I want to keep a battery so can charge mobile phone etc while stationary.

[bookertmgs1]

Have you considered an Intelli-convertor from Scootronics ?

We had issues with maintaining a consistant supply for phone charging & sat navs - this sorted it.

there are different models - some with integrated USB ports - others without.

there is a website - but probably quicker messaging through facebook

[Fast n Furious]

Standard shunt regulators (Zener diode) do not produce a pure DC output. They give a pulsed DC output which averages out at around 13.5VDC.
A series style regulator will resolve this issue.