Half dead NiMH cells they do stop responding at trickle charge

[Kiriakos GR]

Yes Half dead NiMH cells, they are unable to collaborate as we should expect at trickle charge.

Battery charger trickle charge mode, this offer a pulse of DC current, every few seconds.
A good working battery with normal or small internal resistance, this can use this DC current pulse, so it voltage this to elevate a bit.

Trickle charge concept this has it roots at Law of Ohms.
When battery cell internal resistance this increases to much.
DC current fixed pulse this becomes ineffective.

Therefore the expectation, of this battery cell to retain a stable top-up voltage, this is not electrically possible.
No one can get away, or violate the Law of Ohms. 


A few more explanation's they can be found here.
https://www.ittsb.eu/forum/index.php?topic=2159.0
 
 

[Andrew-88]

No one can get away, or violate the Law of Ohms. 

At ACV applications, anyone who dare to violate the Law of Ohms, he is not today within the living ones. 
 

[overvolt]

Kiriakos he did pointed out again,something of very high significance. 

Trickle charge effectiveness this is a puzzle and for large installations, of UPS backup systems these supported by AGM cells.
Know servicing recommendation, AGM cells replacement over a schedule, even if the old ones they are still working properly.

An more modern and further cost effective servicing recommendation, this is individual cell inspection, by taking measurements of internal resistance.
This is a more wise approach, than blindly swapping AGM cells at a schedule.

At the European Union we have start to become smarter, not all aged AGM they end up for recycling.
There is a new stage of battery inspection, and the formation of battery bank for lesser demanding applications.

Either way, if you are up to battery cell evaluation, you need to own specific testers, them able to deliver reliable measurements.
Only then, you may start saving money and time.