Animalector
New Member
- Joined
- Sep 19, 2020
- Messages
- 7
Hi all,
I have a first generation Sungrow SH5K inverter - First generation meaning no firmware updates and limited functionality. it's almost 8 years old, so it has been a reliable system.
I originally had it running a 48V lead acid battery, but now have a DIY LiFePO4 using Voltax 302Ah cells with CAN integration to a Batrium BMS running Project Lychee comms protocol.
The SH5K has some issues identified in the video above, like you cannot actually run it to 100% SOC... Also the cells that came out of the Voltax 12V batteries were.. err.. not A-Grade..
Some shots of the cells here:
Anyway, the reason for the post is to ask why I am getting AC voltage on the battery. It measures about 70V ish.
I don't want to earth the Negative of the battery pack, because I figured if this was desired, they would have earthed it in the inverter. The Sungrow SH5K Manual is silent on earthing for the battery. I didn't think it was necessary and once it is tucked away in it's box it's all fine..
The reason I am asking is because I want to DC-couple a second MPPT to the battery to "boost" it in the morning so it wil charge to full throughout the day, currently the solar is insufficient to charge it fully thoughout the day unless it's zero clouds.... plus it's hot here, and we like Air-con.
QUESTION: Will I have an issue DC Coupling a MPPT 150/45 to the battery?
Thanks all
Andy
#300SunnyDays
I have a first generation Sungrow SH5K inverter - First generation meaning no firmware updates and limited functionality. it's almost 8 years old, so it has been a reliable system.
I originally had it running a 48V lead acid battery, but now have a DIY LiFePO4 using Voltax 302Ah cells with CAN integration to a Batrium BMS running Project Lychee comms protocol.
The SH5K has some issues identified in the video above, like you cannot actually run it to 100% SOC... Also the cells that came out of the Voltax 12V batteries were.. err.. not A-Grade..
Some shots of the cells here:
Anyway, the reason for the post is to ask why I am getting AC voltage on the battery. It measures about 70V ish.
I don't want to earth the Negative of the battery pack, because I figured if this was desired, they would have earthed it in the inverter. The Sungrow SH5K Manual is silent on earthing for the battery. I didn't think it was necessary and once it is tucked away in it's box it's all fine..
The reason I am asking is because I want to DC-couple a second MPPT to the battery to "boost" it in the morning so it wil charge to full throughout the day, currently the solar is insufficient to charge it fully thoughout the day unless it's zero clouds.... plus it's hot here, and we like Air-con.
QUESTION: Will I have an issue DC Coupling a MPPT 150/45 to the battery?
Thanks all
Andy
#300SunnyDays