Battery charger idea...

I'm toying with the thought of building a rechargeable battery system, using a number of cheap Li-Ion and NIMH battery chargers, controlled by a timer to keep the batteries ready to use, while preserving their maximum life cycle.
For this purpose I collected some data:
1) Li-Ion batteries like frequent charging to 60%, whereas 100% charging shortens their lifespan.
2) Best is a separate, slow charging charging circuit for each battery.

It would be useful having four batteries of each type at any time ready for use and welcome any suggestions on this idea...
Regards and Thx in advance, Joh

"Li-Ion batteries like frequent charging to 60%, whereas 100% charging shortens their lifespan."

Do you have a source for this statement? I was under the impression that, 100% charging, done properly, is the way to go.

I'm not being sarcastic, I sincerely want to know.

A Lithium battery does not need and does not like to be frequently charged because it can hold a charge for years.
The Lithium battery from my daughter's first cell phone has not been used or charged for about 14 years and still has a pretty good charge.

The Lithium-Polymer (Li-Po) batteries used to power my radio controlled model airplanes are Lithium-Ion and are shipped half-charged. They last longer if they have a storage charge that is half of a full charge.
It is recommended to discharge them to half of a full charge when storing them for longer than two weeks.

Spend some time at www.batteryuniversity.com