ITTSB.EU Blog Forum
Significant information’s in favor of a professional Workshop => All about NiMH and Ni-CD chargers in European Union => Topic started by: Kiriakos GR on November 06, 2025, 07:07:36 PM
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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. ;D
When automation this is missing, some one should do manual labor.
An overpriced resistor? ;D
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 ;)
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Today I have be impressed, by the amount of information, this is known by academics.
But I was not prepared, to deal with the complexity of this scientific style of writing.
Attached, this is a Free document.
Tittle: Review, Capacity Degradation Mechanisms in Nickel/Metal Hydride Batteries
By two Japanese authors, Kwo-hsiung Young and Shigekazu Yasuoka
Within it, it is described, that an overheated battery due charger fast rate, this will accept overcharge because battery voltage this always appear as less when the battery is hot.
No one ever wrote before, that overcharge due a Fast charger, this is No1 reason at causing battery capacity degradation.
As No2 reason at causing battery capacity degradation, this is electrolyte evaporation, when battery runs hot over a charger.
As No3 reason at causing battery capacity degradation, this has to do with the quality of electrodes (+ & -), and of how many ways they are, so electrodes reliability this to be increased.
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Since December 2025, I have stop using Quick or Fast chargers.
I did find a slow charge charger, with advanced electronic controls, this is development of 2023.
Suddenly all my NIMH cells they start lasting longer, even used Eneloop they have recover to a better condition.
There is no heat when the batteries charging. :)
I am two times happy now, because I had start sensing the problem, but I was not able to explain it in full, I do not have university degree.
But this document of scientific origin, this worked as confirmation, of what to not do, and of why ... so your NiMH cells these to last much longer. ;)