With it’s 12 V power input the Home Assistant Green sounds like an ideal candidate to be connected to the 12 V battery in a car or van. But voltage can be up to 13.5 V when the battery is fully charged. Can Home Assistant Green tolerate this slight overvoltage or should it be only connected via a DC/DC buck converter to guarantee the voltage is not above 12V?
#Allowed input voltage range for Home Assistent Green?
south sun
somber yoke
I would go the guaranteed 12V route. Just to be safe.
alpine arch
Open it, find the voltage regulator, if any, and check its spec sheet 🙂
sleek elm
The website says:
Power supply
DC barrel connector, 5.5 mm * 2.1 mm
12 V DC, 1 A
I would suggest get a buck-boost that will do a couple of amps and put that in there. Should be very cheap. That's the safe route.
If someone knows the FCC number you could look at the FCC website to see the regulator.
alpine arch
I know but everything has some "boundaries" for lack of a better word.
sleek elm
True but let's face it, it it's going in an RV you might get low volt situation and a buck-boost would cover a lot of problems that way. Plus a solar charger, generator, battery, shory power, alternater chargr, lots of weirdness going on there.
I help a buddy work on the one they own, lots of weird iron in that thing.
Theirs had an aluminum bus bar inside a box for flipping the different charge sources, and the aluminum connection was 10k ohms, physically bolted together. We pulled the aluminum bar out and put a brass bar in...
Was supposed to be 0 ohms...
half crow
Although you say "voltage can be up to 13.5" I suspect that's only when off charge. When being charged it will probably go a lot higher than that.
Worse than that:
- charging voltage is not pure DC, it's probably rectified AC from an alternator (ie, if you measure 15v with a voltmeter when charging, the peaks will be 22v)
- when using the starter motor, the battery will drop temporarily to a very low voltage -- probably low enough to cause a reboot
So I'd say definitely put some kind of regulator between the supply and HA and you might also need a secondary battery
https://www.amazon.co.uk/Yangers-Uninterrupted-Supply-6000mAh-Battery/dp/B0C9QG76HF looks as if it would do that, but check the polarity -- it's not specified and may need reversing
south sun
Don't think voltage is changing that much. Battery is brand new LiFe type and the alternator is connected via a charging booster that controls the voltage.
But if the HA Green requires a regulated 12V power input a buck-converter is a requirement. Frankly its cheap but what I don't like is the radio frequency these generate and the loss of power only for reducing the voltage from 13.5V to 12V.
I‘ve already looked into 12V power banks. Those would not only produce a reliable 12 V input for the HA green but double as an UPS. Unfortunately I wasn't able to find one with a wider input power range like 12-24V.
The one you suggested seems to require 12V as input as well.