Best to Rest Before Charging?

[jayflash]

The Maha C9000 rests the cells between discharging and recharging, for one or two hours, I believe, as mentioned in another thread.

If more info about resting cells exists, I haven't found it and I don't think Battery University indicates a rest period for any cell chemistries. I could be mistaken, however.

Other than insuring cells are cool enough, are there other reasons to rest a cell after discharging, before recharging? Is this true for only some cell chemistries?

Thank you for any info.

 

[BoarHunter]

For a bull, yes definitely, it will help win the fight ! :)

 

[Mikl1984]

If more info about resting cells exists, I haven't found it and I don't think Battery University indicates a rest period for any cell chemistries.

It's requirements of current IEC Standard 61951-2:2003: more than 1 hour and less than 4 hours between 16-hours charge and discharge:
- for capacity measuring
- for cycling every 50th

 

[Battery Guy]

Other than insuring cells are cool enough, are there other reasons to rest a cell after discharging, before recharging? Is this true for only some cell chemistries?

From a practical, every day use situation, the temperature thing is pretty much the only thing that you need to be concerned about. If the cells are reasonably cool, go ahead and throw them on the charger. This is exactly what your laptop computer, cell phone and other devices do.

It's requirements of current IEC Standard 61951-2:2003: more than 1 hour and less than 4 hours between 16-hours charge and discharge:
- for capacity measuring
- for cycling every 50th

The reason that IEC wants you to wait 1-4 hours has more to do with standardization than anything else. They have to say something in this regard, and the 1-4 hour range was apparently reasonable enough that the entire IEC standard committee agreed to it. Remember that the IEC standard is not the best way to charge and discharge a battery, it is simply a standard way of doing it so that everyone reports total cell capacity the same way.

Cheers,
BG

 

[Mikl1984]

Remember that the IEC standard is not the best way to charge and discharge a battery, it is simply a standard way of doing it so that everyone reports total cell capacity the same way.

Agreed, but not capacity only. Cycling too;)

 

[jayflash]

Do I understand correctly that if the cells are cool there's no advantage in a rest period between discharge and recharging? The cell's chemistry doesn't need to "stabilize" or rest or for other reasons?

 

[Mikl1984]

Not really
Please make simple test
Discharge cell by Maha and look at V during day or even more
Chemical reactions will reflect in V: 0.9 just after end of discaharge, about 1.2V after 1 hour (will may change to 1.3V in one day)
Better to begin charge with V=1.2 - it's normal condition of cell

 

[Battery Guy]

Do I understand correctly that if the cells are cool there's no advantage in a rest period between discharge and recharging? The cell's chemistry doesn't need to "stabilize" or rest or for other reasons?

Yes, you understand correctly, at least in my opinion (for what its worth).

Cheers,
BG