NiMH 1.2V battery and Maximum aloud charging voltage according to temperature

[Kiriakos GR]

They are two charts below which I did steal from Panasonic year 2024 documentation. 

When we think NiMH 1.2V battery, and then Min Max charging voltages?
As first we need to know our own battery working temperature range.
1) Chart for cells able to function down to -20C
2) Chart for cells able to function down to -10C 

At constant voltage mode, the output this varies according the environmental temperature.
In theory, one good designed charger, this it should include a temperature sensor, this be permanently attached over the battery.
This charger, it is now able to perform automatic micro-metric voltage correction, this also known as voltage compensation range.

Such voltages compensation range, this is required for battery packs them be outdoor or in harsh industrial environments.

At 20C (normal temperature for humans), constant voltage this have a strict range 1.500V up to 1.520V  (DMM at 5V range).
For a 8.4V NiMH PP3, we simply multiply seven times the given value for a single cell.     

If we have a NiMH power pack? Again we multiply voltage value by cells count.

We can use this pack of information's,  so us to form a judgement, if any NiMH charger this is working properly or not.
Regarding voltage tolerances, +/- 5% of error this is ideal, anything higher than that, this is an alert, so us to investigate.