Add JK BMS battery service

[hsteinhaus]

Follow-up of #116

Following changes were made to support integration with JK BMS (https://www.jkbms.com/).:

• cleaned up whitespace in yml
• added simulator script
• removed "persist" attributes for non-settings
• rebased to 0.9.0dev

Some screenshots:

[freakent]

Hi Holger,
Can you explain more about the use case? What is the battery/BMS you are integrating and do you know which Victron product this set up emulates?

I wonder whether this info should be added to the wiki so that anyone else with the same use case can follow your footsteps.

I am aware that Victron use the Battery service to represent many different devices, even the LEDS on the lynx distributor is managed under the Battery service. I have been wanting to redesign the services.yml file for sometime now. One advantage of what I'm planning is that you could define multiple configurations for each service type. I see what you are doing here as one specific Battery configuration for a specific use case.

Martin

[hsteinhaus]

Hi Martin,

my ESPHome-based sensor is interfacing a JKBMS - at least a dozen of different models included. These BMS are very commonly found in a lot of home-built RV, boat or ESS batteries. The most important usecase for me is to monitor the cell voltage difference, battery temperature and alarms, e.g to get an email from VRM if something is going out of limits. If the BMS is capable and trustworthy enough, you could also do things like DVCC, and get voltage, current and SoC readings into the system without using a SmartShunt or BMV.

However, I think the battery service is by no means specific to that special BMS or to my usecase at all. Similar sensors could be built for almost any BMS with any kind of communication (serial, Bluetooth, CAN) available on the market and achieve almost the same functionality as e.g. a Pylontech battery (DVCC etc. included) that is directly supported by Victron.

In my perception, the idea behind com.victronenergy.battery is to provide an abstraction for any kind of BMS or smart battery. I think the fuse status LEDs are seen as a part of that BMS for the Lynx example you mentioned.

Holger