My charger charges 3 times slower than normal conditions
Temp -3 to 3
Is gt normal?
Yes.
But it is the battery who does not allow much current at low temperatures (it is about chemistry). Charger is ok with low temp, actually it likes it (there's a fan who cools down the charger circuits).
And I know it's actually not indicated to charge below 0°. If possible bring your battery inside at room temperature.
In ev cars the battery is pre-conditioned at low temperatures, meaning it's heated before charging, such that the charging is faster and battery damage minimized.
So take care and protect your battery if you want to prolong its life 😉