Text below this is a product review of a young fellow, about one constant current NiMH Overnight Charger
The device has none of the components you would expect from a charger:
No indication of whether the battery is charged.
Worse still: no logic to check it.
Just a table showing approximately how long certain capacities should remain connected and a warning not to exceed them.
The thing is probably just an overpriced resistor...
No indicator
No logic
Manual timing of the charge level Indeed the scientific way at properly charging a battery, this does not include any fun factor.

When automation this is missing, some one should do manual labor.
An overpriced resistor?
This is a very simplified description, even this type of a charger, it does have housing, battery slots, power supply, and one simplified electrical circuit.
At 2025, the few genuine European imports of such Chinese chargers, they are now priced at 11 Euro and even below.
But they are out there and thieves, selling them as high as 17~20 Euros.
We are living in Europe, in which financial uncertainty this is our new major problem.
Even this simple form of constant current, NiMH Overnight Charger, this can and will prologue our NiMH batteries life cycle for few more years.
By using these chargers we save money, and we can use them for something else.
The next level up, these are the Fast or Fastest NiMH chargers. Only few branded and of good quality batteries, they can survive for a few years by them constantly charged by a 2.5 hours charger.
The fasted rapid charge type, it will burn and destroy any NiMH within 15 months or faster.
NiMH batteries for productive work
they are expendable, one small group of people this profiting due it productive work, and the cost of damaged batteries this is a small loss of money for them.
In summary: Rapid charge = sacrificing expensive batteries for a business cause.
2.5 hours charger = Minimal savings in cash
6 Hours charger = Medium savings in cash
12~16 hours charger = Maximum possible savings in cash
I have never seen before an overpriced resistor, this actually paying me with Euros in a long term