Low Voltage Disconnect and Charging Discharging Protection 2 IN 1 40A DC 5V-60V Low Voltage Cutoff with LCD Display Low Voltage Protector Disconnect Switch Module Charging Discharging Protection Board

I've used this specific one, though I'm using 12v and about 3A, not 48v and 10A, but that appears to be well within spec as well: https://www.amazon.com/Disconnect-Charging-Discharging-Protection-Protector/dp/B0C2VMGCZR It's just reading voltage, not SOC, so it will take some fiddling to figure out the on/off voltage settings you want, especially when you have to compensate for some voltage sag, but it shouldn't be too hard. Based on THIS voltage/SOC chart, I would start by trying a power cut at 51.2v, which will probably bounce back close to 51.5/30% when the load is off, then have the load turn back on when voltage hits 52.2. Then adjust from there slightly up and down on cut off and restore voltages.