It is very important that the supply used to power the Raspberry pi is stable, capable of providing 2A and does not create a significant amount of radiated noise either through radio interference or induced noise into the primary power source. This can affect other electronic equipment in your aircraft particularly noticeable in the radio.
For this reason, it is recommended that the Raspberry pi is powered from a good quality portable power charger such as the Anker range of units. Cigarette lighter voltage converters can be used but they must be of good quality and capable of delivering a constant 2A. Beware of running additional consumer items off the cigarette lighter voltage converter as this may reduce the power available for PilotAware and cause the Raspberry pi to reset. If there are any problems with your PilotAware unit then first check that you are using a reliable power supply and a good quality 20ASG cable. This is the commonest reason for failure of the unit experienced to date by far.
If you are operating an EASA aircraft or you want an EASA approved power supply for PilotAware certified units can be bought from www.charge4.co.uk.
Regards
Keith
A quick note on this:
The PilotAware team recommend that a 2A supply is needed for the PilotAware unit, so if you also need to power your tablet/phone/anything else then this is over and above the 2A. This in effect means if you have a single cigarette socket then a supply of at least 3A is needed, ideally one rated more than 3A. Unlike charging a battery where the current draw is basically constant, the PilotAware kit power draw isn't, the power draw depends on what it is doing. You can see the power draw during boot up in this thread
http://forum.pilotaware.com/index.php/topic,401.msg5332.html#msg5332 I plan to take some more detailed measurements over the next few weeks.
My chargers have been independently put through testing and the technical report accepted by EASA for installation into EASA aircraft, work is underway to try and obtain a Minor Mod approval covering a wide range of EASA GA aircraft, unfortunately the wheels within EASA don't turn particularly quickly. The avionics shop that did the work is looking to put elements of the report and comparisons up on their website.
You can install my chargers in LAA aircraft, or plug them in via cigarette lead if needed too, the choice is yours. I have not tested the Anker plug in products so cannot really comment on their performance. As with all these things the installations in GA aircraft are so varied that what works for someone may not work as well, or at all, for someone else.
If you go down the portable battery pack route (i.e. standalone of the aircraft power systems) then just be wary of the power ratings of products. Always give yourself plenty of headroom in terms of battery capacity and the amount of power the pack can supply. Be aware the capacity will degrade over time, that is just a fact of life with the battery technology. Probably bank on replacing them every few years depending on usage. If you don't use them regularly when flying, use them at home every couple of weeks to put them through a charge/discharge cycle as this will help extend the battery. The Anker packs seem to have received good reports within the community.
Yes you do need to use the 20AWG USB cable regardless of power source, the voltage drop otherwise can be too great, especially if the power source isn't all that good. One of the common issues with the cheap chargers is as you draw more power the voltage drops, so although the PilotAware may boot, when it gets up and running weird things happen. This can be because the voltage at the PilotAware unit drops too low and causes issues.
