Hi, I've just published to Github a tool I've developed to limit my batteries maximum load to increase their longevity :
https://github.com/freddez/llcharge
It works with Shelly smart plug, and any device with a fast charger. I use it for my SuperSoco and my smartphones : https://github.com/freddez/llcharge/blob/main/assets/llcharge.toml
Specifically, once the environment is installed, I just have to connect the battery to the smart-plug, turn it on, the battery charges to about 80%, then the charger turns off automatically.
Hope it could help others,
Fred.