The Care & Feeding of Lithium Batteries

I know there are electronic and tech-savvy members of this forum. I am reaching out to them for some real answers to some questions and assumptions I have regarding Lithium camera batteries.

I have quite a few cameras, both film and digital, that use Lithium batteries. Here is what I recall having read or heard about charging and caring for them:

Charge new batteries for at least 12 hours, even if the charger indicates they are fully charged.
Subsequently, there is no need to recharge them back to 100%, 90% is better for battery life.
They lose charge over time. How long is that time? In my experience it can be a matter of a few weeks for some of them.
The Nikon D (professional) cameras come with a charger that allows "conditioning." What does that mean and why don't my other chargers feature it?

Is it OK to let a battery completely discharge and for how long?

Thanks for your input.

What I have learned...

• Lithium ion batteries are better off charging frequently from partial discharge, rather than charge after deep discharge. There is no 'memory' like NiCads had.
• Lithium ion batteries start to lose capacity from the date they are manufactured. You cannot stop this from happening.
• Lithium ion batteries are better left partially discharged before leaving them on the shelf, rather than charging them fully before storage.

No idea what 'conditioning' does or does not do for battery lifetime or capacity.

These sites seem to have some good information
https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries
https://batteryuniversity.com/article/understanding-lithium-ion
https://www.techrepublic.com/blog/five-apps/five-tips-for-extending-lithium-ion-battery-life/
https://www.powerelectronics.com/ma...859861/proper-care-extends-liion-battery-life

I've been riding eBikes w/ lithium batteries for many years. With the first one, I would run the battery way down, then charge it back up. It lasted one year. Bought the same bike again, and this time I never let the battery get below 50% charge, and I charge it back up until the charger light goes off. Every now and then I give it a long, 12 hr slow charge. That battery is 2 1/2 years old now, and still as powerful as the day I bought the bike. So that obviously worked well.

Go to the eBike forums (endless sphere is a good one), those folks build their own batteries and know all about how to care for them. Also, make damn sure you don't leave your charger on a combustible surface. Lithium batteries can and do occasionally go up in flames, and charging may lead to that if there's a defective cell in the battery. One eBiker had his house burn down when he left the bike on the charger and left for a spell. Lots of youtube videos of eBikes going up in flames, and when it happens there is no warning. It just goes up in flames, and a very hot fire too.