Connecting 4 48V battery pack in series to get 192v high voltage battery system

stirucherai

New Member
Joined
Mar 9, 2021
Messages
7
Connecting 4 of 48V LFP batteries in series.

Trying to install 5Kw 3phase hybrid solar system (3phase is mandated to connect to grid). All the 3 phase 5kw hybrid inverters operate on high voltage batteries 160v+. These are offered by Pylontech / BYD but are 3 times more than regular one. Question can we connect 4 48V 2.5Kwhr batteries in series.
1. Do know that amps need to be matched for charge and discharge and also the low voltage cut-off. the batteries pack by itself have 39v low voltage cutoff and high voltage cut-off at 54v. So internal BMS of one pack will disconnect when its voltage reaches 39 or 54 there by disconnecting all of them.
2. Internal BMS of 48V pack will disconnect as soon as one of the battery pack reaches low or high voltage -- this might lead to one or 2 batteries been beaten and hence lesser self life. With LFP batteries expected to reduce price in next 2 to 3 years willing to take this risk and proceed.

What other downside if we connect in series and connect to inverter (other than the issues highlighted above)

Thanks and Regards
Sarang
 

Panamask

New Member
Joined
Aug 11, 2021
Messages
5
I have 16 12V batteries connected in series to make 192V. My charge controller handles 340V from the panels. Bulk charging is 225V, float 117V. Don't know what your battery AH are. My system is 10KW and l have never seen more than 18 amps on the charge controller. Have to say that my battery voltage has never been lower than 201V and that was after using a lot of energy during that particular night. Normally l see 204 to 205V in the morning. 207V is full. I am off grid.
 
Top