A4 supported power voltage range

[mikesloper]

What voltage range can I power the A4 board with? I am using LifePO4 battery with a voltage range of 11v - 14.7v. Is this OK?

[admin]

A4 use DC12v power supply, because relay's coin is DC12v, if you use 14.7v, long time for relay ON, relay coin will become hot.

[cabinlab]

Do you mean the "relay coil" will get hot?



The datasheet for the JQC-3FF 12V relays says the voltage limit at 20°C is 14.4V. That is a normal range of 12V nominal systems.

The other components in the Power Supply section have tolerances of 35-40V, so can you help us understand the 12V limit instead of 14.4V from the datasheet?



Is there another component on the board causing the relay to overheat?

[admin]

only relay need to test, you can add 14v for a testing when long time work.

[cabinlab]

What voltage range can I power the A4 board with? I am using LifePO4 battery with a voltage range of 11v - 14.7v. Is this OK?

Hey Mike, I've been looking into this question a little more for my own battery use-case as well. This AZ943-1AH-12DEF relay is very close to the ones on the A4. If it's absolutely necessary to test higher voltages, desoldering the originals and replacing with  something like that may be an option.

The datasheet says the 12V version can handle 26.8V continuous, with the same Must Operate Voltage (minimum) of 9 that the originals have.


It comes in a few versions, including one with upgraded insulation which can dissipate up to 2.4W of coil heat continuously.

I haven't done a super deep dive on it, and there are other variables and variations which may prevent this particular relay from functioning properly in the A4. With a little more research, it might be worth the $0.87 to try the right one out.

My LifePo4 bank doesn't usually go above 14.4V, so I'm going to test the regular relays first.