SIM Injector 56V power on a yacht


I’ve a customer who is looking about to buy an HD2 DOME and and SIM Injector.
He has an issue though - his boat runs 12V.
Does anyone have any suggestions for getting 12V to the 56V needed for the SIM Injector to provide PoE to the Dome and AP One ENT.
The SD-PMU can take power upto 52V but this is not quite enough.


Pretty sure the SIM Injector is 12-56V I bet if you give it 48V+ it’ll support POE output on the LAN ports to power the HD2. To do that you could use a boost converter like this one.

Hey @Travis You’ve got a HD2 Dome in your car right? Is that with a SIM injector? If so how are you powering it?


there are plenty of poe injectors available that take one power and output another… have you searched at all? amazon, ebay, google?


The SD-PMU can be powered by 12V -> hook this up to Sim injector and you’re away laughing like Martin said?


I have a PMU hooked to my vehicles constant and ignition voltage. The PMU then powers the SIM Injector which powers the HD2 Dome. The 52V PMU output is plenty to get it all working.

We have also renamed the PMU-LTE to the BR1 Power, this is the PMU with a dedicated LTE radio for out of band power monitoring and control, along with the DC boost functions the original PMU has.

pepwave-max-br1-power_datasheet (1).pdf (1.1 MB)


This looks good, but the Datasheet is confusion me a little bit.
In the Specs the Output is up to 52V

In the picture of the Datasheet it is 56V
What is the correct maximum output Voltage?

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Well spotted @dennis.hofheinz - this is why I asked the question initially as the PMU states 52V output and the SIM Injector needs 56V.
“The SD-PMU can take power from sources with low or fluctuating voltage and turn them into a reliable streams of upto 56V power.”
@Travis has it working so it would appear that an output of 56V is covered.


Don’t forget too, there will be cable loss over the ethernet cable leading to the HD2 dome from the power source, the HD2 will have a minimum voltage requirement which is lower than 56V.
Does anyone know what this is?


The HD2 Dome supports POE+ power standards (802.3at) which states voltages can be between 44 and 57 volts DC, so if you provide the SIM injector with 48V it will then do POE passthrough to the HD2 no problem, you can also give it less (eg 12V) and power the HD2 with an inline POE+ injector or Switch if you have one available.

On a boat I would likely use a 12v to 48V step up voltage regulator like this one. Or if it was big enough to have a comms rack that is always powered add a POE+ switch to that.