I'm reading smart shunt power and the battery will charge at what I set mn15 aoi which is 3kw but once the battery hits 90%, the charge power drops to 1kw. Is this the programmed behavior?
You would have to know that your smart shunt and battery SOC are on the same page as far as calibration.
But it also seems a bit of a mystery of how controllers or inverters do their closed loop charging. I haven't found anywhere yet that explains the order of operations of how they work for any of the various brands of controllers or inverters out there.
Seems like they all might be different how they go about it too.
Larry
Yes, in this case, I want to know about the powerflo16 and MN15 in closed loop operation. I clearly see a connection when the powerflow16 hits 90% (not the smartshunt but the actual SOC as reported by the BMS over CAN bus to MN15) and the reduction in power to around 1kW charging.
I believe you are seeing the roll back on charge current at the top of the charge cycle. As the battery is almost full we throttle back the current. This is normal behavior and extends cell life
Quote from: FNG on February 10, 2025, 07:51:07 AMI believe you are seeing the roll back on charge current at the top of the charge cycle. As the battery is almost full we throttle back the current. This is normal behavior and extends cell life
I would like to see this documented a bit more but also 90% is a bit too soon to slow down don't you think? Let me explain a bit more. When the battery doesn't get charged to 100% for a few days, the bms does not know about the constant 33w draw the inverter takes and losses a few kWh over a few days. The battery then starts charging and reaches 90% but it is really not so it now slow charges for a long time until the programmed bulk voltage is reached.
I think the better thing to do is to slow down once the battery hits a predefined voltage like 3.4v per cell. I'd be cool with that.