I’m considering installing two 200 amp Victron NG lithium batteries, and I need to know what additional items are necessary in order to monitor the batteries. I have a Victron 12/2000 multi plus inverter charger.
You must install one of the NG BMS units, small BMS BG, VE Bus BMS NG or Lynx Smart BMS NG. Have a look to decide which would suit your system and what monitoring you want. The Lynx Smart BMS has Bluetooth so you can monitor it locally, do not think the others do. You may also need a GX communication device.