The battery is good value the money. The capacity, cables, and form factor are all great. The Bluetooth app works well and I was able to communicate with EG4 6000XP (capacity and SOC) using the inverter's lithium battery setting 2.
I had two issues with my batteries. First the packing material were insufficient to protect the battery during shipping. The steel case appears to be a bit thin for the weight of the battery and a couple of corners had some damage and the front panel of one of my two batteries also had dimples in the steel from light damage.
Another issue I experienced with both batteries was related to low temperature discharge cut off. There are two low temperature cut off settings, one for charging and the other for discharging. The low temperature cut off for charging works correct, but the low temperature cut off for discharge does not. When the battery temperature falls below the charge cut off set point, the battery also also disables discharge (despite a lower discharge cutoff set point). This effectively means you can't discharge these batteries below freezing.
I was able to overcome the low temperature discharge cut off issue by building a small insulated enclosure and added some greenhouse heating pads to keep the batteries warm enough to charge and discharge.
Although there wasn't a firmware patch to fix the low temperature discharge cutoff, communication with Humsiemk customer service was pretty good. They were responsive and made a genuine effort to achieve a satisfactory outcome.