LiFePo TAICO 19" Rack Battery with Growatt SPH4600 - Overcharging

[SimsonS53]

Good Day,
I've my Solar installation up and running since about two weeks.
(Don't get me started about the hilarious amount of bueraucracy that is involved here to get it legally allowed)

To my problem where I'm struggeling with,
it seems that the inverter continues to charge the battery with solar power, even when reaching 100% SoC.
Yesterday I took a chair and watched what happens.
The Inverter slows down the charging when getting close to 100% to around 5.3A.
But keeps that current going even if the BMS reports 100%, as the display of the inverter tell me the same.

Soon as the Voltage reaches 55.2V the BMS disconnects the battery to protect the cells from overvoltage.
The inverter recognizes that with "BMS Error 301" or some days ago with "Bat Open".
Problem is that the BMS now in Protection mode, and it has to be manually reset.

I've played around with multiple inverter settings but nothing seems to help.
Today I've set the inverter to "Bat First",
(because this is the only mode which let you cap the upper SoC) and increased the time window from early morning to eveneing.
I've now set the upper SoC to 95% and I hope this will stop the overcharging.

The battery is connected via an RJ45 cable to the 2nd port from the left, for CAN Bus.
And the battery should be already be configured for using the "Growatt" protocol, according to the seller.
Unfortunatly I don't have the correct PC software to check it myself via RS323.
And all my self made cables with USB to serial cables that I have right now refused to establish connection,
with the Sofware that I found somewhere on the web.
So I have bought the recommended cable from amazon...


Anybody has similar issues with the charging behavior of non- Growatt Batteries?
I would expect that the inverter stops at 100% SoC...

 

[sunshine_eggo]

First, SoC is a calculated value and it is commonly off by a significant amount. There is no logic in the system that tells it to stop charging at 100%.

Charging is regulated by individual cell voltage. As the highest cell crosses a threshold, current is reduced in stages until a cutoff is reached.

That company apparently offers both 15S and 16S versions. If 15S, 48V will be listed as nominal (4800Wh). If 16S, 51.2V will be listed as nominal (5280Wh).

For 15S, 55.2V/15 = 3.68V/cell = very highly charged.

For 16S, 55.2/16 = 3.45V/cell = 95%+ charged at very low current.

Best option in either case is to set battery type to USE and set absorption at 54.8 (51.5) and float to 54.7 (51.4) for 16S (15S). If this changes the BMS behavior, it's likely that the cells are imbalanced, and they simply need time at elevated voltage to balance.

 

[wil974]

Good Day,
I've my Solar installation up and running since about two weeks.
(Don't get me started about the hilarious amount of bueraucracy that is involved here to get it legally allowed)

To my problem where I'm struggeling with,
it seems that the inverter continues to charge the battery with solar power, even when reaching 100% SoC.
Yesterday I took a chair and watched what happens.
The Inverter slows down the charging when getting close to 100% to around 5.3A.
But keeps that current going even if the BMS reports 100%, as the display of the inverter tell me the same.

Soon as the Voltage reaches 55.2V the BMS disconnects the battery to protect the cells from overvoltage.
The inverter recognizes that with "BMS Error 301" or some days ago with "Bat Open".
Problem is that the BMS now in Protection mode, and it has to be manually reset.

I've played around with multiple inverter settings but nothing seems to help.
Today I've set the inverter to "Bat First",
(because this is the only mode which let you cap the upper SoC) and increased the time window from early morning to eveneing.
I've now set the upper SoC to 95% and I hope this will stop the overcharging.

The battery is connected via an RJ45 cable to the 2nd port from the left, for CAN Bus.
And the battery should be already be configured for using the "Growatt" protocol, according to the seller.
Unfortunatly I don't have the correct PC software to check it myself via RS323.
And all my self made cables with USB to serial cables that I have right now refused to establish connection,
with the Sofware that I found somewhere on the web.
So I have bought the recommended cable from amazon...


Anybody has similar issues with the charging behavior of non- Growatt Batteries?
I would expect that the inverter stops at 100% SoC...

Hey, i hope you are ok! I have exactly the same issue with a Bettenergy batterie ( 4,4 kWh) and a SPH3000 inverter. Did you find a solution to this?