Accumulators are Top, safety charger flop

Unlike the charger, due to its low weight, I looked at the inner workings and distant this.
As so often with super cheap China power supplies also here: isolation distance is insufficient, no interference suppression. That it is cheapest circuitry is clear. CE mark as never legally acceptable.

A typical candidate for self flared devices since no backup is installed.

I built inside a properly charging circuit (1A) (China 1.-), drew 2 LEDs in the lid and provided all with a quality 5V power supply. Now it's perfect for the housing and the charger do their duty.