LG Chem 2KWH 48Volt Power Wall for off grid house

[tanoshimini]

Good to hear. I’m also babying my batteries because my tiny solar array will only send about 22 amps into the battery at peak and I’ve limited my charging from grid to a similar 20A.

I took another look at your battery configuration and noticed the smaller control wires through the middle. Are those for the can bus?

no, actually those are for the thermistors that are built into the packs. once I pulled out the built in bms, I kept the thermistor leads in case I ever wanted to use them in the future. at the time, I was way more concerned with temperature than I am now.

so much of the worry out there with "lithium" batteries is concerning the LiFePO chemistry, without noting that... people seem to lump all of the lithium chemistries together.

 

[paulmurdoch]

It looks very neat. The inverters are connected to the net, so I got the alarm but at the time I had no generator connected, so it was like slow torture as watched the voltage drop. At the time I only had 3 combined batteries set up in parallel and voltage charge was too soft taking each cell to float at 3.9volts. Now I push the cells to 4.1V and float at 4V, which gives me so much more KWh. I'm now connected a generator, so hopefully I'm fully covered.
The small wires are connected to each cell + connected to my Dally bms. I have 4 BMS One for each battery managing the 14s configuration. Unfortunately, the Daly is only Bluetooth, so I have to be on-site to view what's going on but so far they seem to be doing their job.

 

[paulmurdoch]

Quick update! X4 14s 48V system all completed and working like a dream. It was a challenge and a great learning curve. Thanks to all who contributed, I really appreciate the help.

 

[poldim]

It looks very neat. The inverters are connected to the net, so I got the alarm but at the time I had no generator connected, so it was like slow torture as watched the voltage drop. At the time I only had 3 combined batteries set up in parallel and voltage charge was too soft taking each cell to float at 3.9volts. Now I push the cells to 4.1V and float at 4V, which gives me so much more KWh. I'm now connected a generator, so hopefully I'm fully covered.
The small wires are connected to each cell + connected to my Dally bms. I have 4 BMS One for each battery managing the 14s configuration. Unfortunately, the Daly is only Bluetooth, so I have to be on-site to view what's going on but so far they seem to be doing their job.

If you want to extract more data from your system, you can spend 10 bucks on 4x wemos d1 mini’s and pull in the data into home assistant or MQTT via ESPHome: https://esphome.io/components/sensor/daly_bms.html

 

[poldim]

Quick update! X4 14s 48V system all completed and working like a dream. It was a challenge and a great learning curve. Thanks to all who contributed, I really appreciate the help.

Nice looking system! How are you protecting each of the 14s strings before you combine them and send them to the inverter?