Battery storage:

[kenevonaive]

I fully charged my battery a week ago only to find out of the Corona pandemic 3 week lockdown,my question is,should I discharge it half way for I heard it's not good to store it fully charge?

 

[MattyB]

Yes, make sure you get it down to at most 80% if you are not going to use for a long while - storing at elevated SOC (anything over ~4V/cell) is a pack killer in the long term, especially if you live somewhere hot.

 

[Mcharza]

If your storage time is about 1-2 months, then there is no harm even the battery is fully charged

 

[MattyB]

If your storage time is about 1-2 months, then there is no harm even the battery is fully charged

Sorry, but that is not what the science says. The greater the amount of time spent at an elevated SOC, the more the pack is damaged - the chemical processes associated with are accelerated at any time the battery is near full charge, so lessening the total time it spends there is always a good idea. It's true leaving it for a day or two at full charge every now and again will probably have little impact of the course of it's life, but any extended period will cause degradation at the anode reducing capacity, cycle life and the ability to deliver current.

BU-808b: What Causes Li-ion to Die? – Battery University
How to Prolong Lithium-based Batteries - Battery University

 

[Jackware]

From the Bosch battery guide;

Charging – The batteries should be charged at room temperature in a dry location where a smoke detector is installed.
Storage during winter – Store the batteries in a dry location at room temperature.
Fully charging or fully discharging results in higher loading of the battery.
The ideal charge status for storage is approx. 30 to 60 % or two to three LEDs on the battery indicator.

From the Yamaha guide;

Storage
Store the system in a place that is:
• Flat and stable
• Well ventilated and free from moisture
• Sheltered from the elements and from direct sunlight

Long storage period (1 month or longer) and using it again after a long storage period;

• When storing the bicycle for a long period (1 month or longer), remove the battery pack and store it using the following procedure.
• Decrease the residual battery capacity to where one or two battery capacity indicator lamps are lit, and store it indoors in a cool 15–25 °C, dry place.
• Check the residual battery capacity once a month, and if only one battery capacity indicator lamp is flashing, charge the battery pack for about 10 minutes. Do not let the residual battery capacity become too low.
TIP
• If you leave the battery pack at “full charge” or “empty”, it will deteriorate quicker.

 

[kenevonaive]

Thanks for all your insights!

 

[I want my 2 Dollars!]

Sorry, that is not good advice. The best way to treat Li batteries isn't opinion, it's chemistry. If you Google you'll find a ton of stuff on this. Current batteries have a nominal voltage of 3.7v. This is where the battery is under least stress. It's around the 60 percent charge mark. Storing at around 65 to 70 percent will keep your battery happy. 30 is too low and puts stress on it. 100 pct also puts stress on your battery. So if you want to get the best life. 100 percent only when necessary or every 4th or 5th charge to balance the cells. And don't leave it sit at 100 if you can avoid it. Think of it like a balloon that's pumped to near breaking. If you get home from a ride and less than 55pctb then charge back to 60 or 70. If you don't need to charge, don't. Don't charge to 100 unless there is a reason.
At the end of the season charge to 65- 70 and store in cool dry place. If you have a spare fridge that is great.
Not in freezer