View single post by Robert

Posted: Wed Dec 3rd, 2014 02:31

Joined:	Sun Apr 1st, 2012
Location:	South Lakeland, UK
Posts:	4066
Status:	Offline

Not an authority but I do know there are different technologies of rechargeable battery, NiCad, LiIon and NiMH. As far as I understand it the NiCad are best discharged then re charged. The other two it's less important. I leave my MacBook pro plugged in almost continuously but allow it to discharge from time to time. I never turn it off unless I actually need to. It's over 4 years old now and the battery still seems as good as the day I bought the computer, If I leave it in it's case for a week, still turned on, it will still have enough charge to be used for a while. Much longer than that and it may turn itself off.

My D200 batteries are always discharged before re-charging, Again I am still on my original Nikon batteries which still perform well. I bought my first D200 in August 2007, 7 years ago, although not in continuous use, they have had their fair share of use.

My power tools get a lot of use, I almost always discharge then recharge those batteries. What I have found with the NiMH batteries is that one day they are good, the next they are bad, (rejected permanently by the charger) there does not seem to be a gradual reduction of capacity, which puzzles me.

I have quite a lot of AA NiMH cells, the most recent batch being 2600 mAh. This latest batch have been the least reliable, failing while many of my early cells are still performing well, which has generally put me off the rechargeable AA cell except for flash guns.

It would seem there is a distinct cut off point beyond which the battery is no longer capable of, or perhaps safe, to continue recharging.

I know there is a ton of data about this on the internet but take some of it with large pinch of salt.

Perhaps JK can shed some light on this?

____________________
Robert.