We brought our Fogstar Drift ECO for our caravan 11th October, it is fitted with a Victron MPPT controller and 2 x80 watt solar panel in series, the isolator switch in the caravan is off to date the battery and solar has held good charge, over the last few days despite being feed by the solar the battery in the day dropped back to 12.7v, for some reason yesterday morning it dropped below 8v. I have checked for any leakage, none showing, the battery has now recovered to 11.74v, this morning showing 11.5v. I contacted Fogstar yesterday, they have raised a ticket and aim to respond in 72 hours?
You can safely discharge the Drift LiFePO4 battery down to -20°c degrees with no issues, the Eco’s JBD BMS is set to allow this. The issue is charging the battery, as this can cause damage if done under 0°c.
The Drift eco’s heating pads are only activated when the battery is being charged, and are powered by the incoming charge current, not the battery itself.
If you put the battery on charge, it will heat the battery first, and then allow current through to the battery when the temperature is safe enough to do so.
charging parameters 12V = 14.2V Bulk/13.6V Float
Was yesterday colder meaning your Solar could only power the battery heater?