Arduino Without Regulator and Battery

I’m currently running a 3.3V Arduino with a LiFePO4 battery. The nominal voltage is 3.2V and max is typically 3.4V. I am not using a regulator nor reverse polarity diodes since it will drop the voltage too much. Is there any harm/risk in not using diode protection besides plugging in the battery incorrectly?

No. But reverse polarity diodes won’t drop any voltage.

@aarg. How do You install such a diode without havin a voltage drop? As shortcuitring ones? If so, wich diodes survive that facing a LiFePO4 battery?

Railroader:
@aarg. How do You install such a diode without havin a voltage drop? As shortcuitring ones? If so, wich diodes survive that facing a LiFePO4 battery?

I have seen reverse polarity diodes on power inputs. What other kind could the OP be referring to? Those definitely can't drop any voltage because they are in parallel with the power input.

Sometimes there is a series Schottky, but I didn't take the OP to mean that, as it is not reverse connected.

Do the LiFePO4 batteries not have short circuit (overcurrent) protection?

@aarg. How do You install such a diode without havin a voltage drop? As shortcuitring ones?

Right. A reversed-parallel diode only conducts if the battery is connected backwards.

If so, wich diodes survive that facing a LiFePO4 battery?

Normally, you add a fuse.

You could show how those reverse diodes are connected. Applied in the powerline they must be in serial, giving a loss of voltage.
Aplied in parallell to the power source..... I've never heard any successful connection like that. 10 -100 Amps diodes?
Schottkys have a lower voltage drop than Silicon diodes. Some 0.2 volts compare to the characteristic 0.7 for silicon. I've not Heard about serially connected Schotkies, only Silicon ones.
Battories having short circuit protection? Maybe, but what diode will survive discipating all that energy?

@DVDdoug
Yes, a fuce blowing diode might work. High, nasty currents but a rather low voltage drop across the fuse. I've never seen it being used...

Aren't LIPO battery connectors polarized anyway?