Solar question-help needed

[hierony]

Now you're thinking! Inverters have that standby current draw, so using that voltage regulator (buck converter) for your 5 V electronics is an excellent idea since you'd just be rectifying the AC back to DC anyhow. As long as the voltages match and the regulator can supply as much or more current then needed it's fine--the load (your booster) will set the current used.

One big thing to watch out for is nominal vs actual voltages--'12 V dc' solar means the actual voltage can vary between 10 V up to 18 V dc on the panel side! With the batteries hooked up, you probably won't get above 15 V though. The voltage regulator is spec'd for up to 23 V, so that's fine. The 12v timer just says '12 V dc' so I can't really say--someone else selling the same product might give better information, or there might be hints in the reviews.