In short
- Cell limits protect the cells; pack limits are only a backup. Set the cell values first.
- Leave a gap between a limit and its recovery value, or the BMS will switch on and off in a loop.
- Charging below 0 °C damages LiFePO4: the low-temperature charge limit is not optional.
The values below are common starting points for LiFePO4 cells, not instructions for your exact pack. Your cell datasheet has the final word, and the settings menu differs a little between Daly board generations. Write down the current values before you change anything.
Cell over-voltage
LiFePO4 cells are full around 3.45 to 3.55 V under charge. Many builders set the cell over-voltage protection near 3.60 to 3.65 V, with recovery around 3.40 V. The charger or inverter should stop earlier than the BMS: the BMS is the safety net, not the normal end of charge.
Cell under-voltage
Below about 3.0 V a LiFePO4 cell has very little energy left. A protection around 2.70 to 2.80 V with recovery near 3.0 V is a common choice. Set your inverter to stop well before this, so the BMS rarely has to cut.
Pack voltages
The pack limits are usually the cell limits multiplied by the number of cells, slightly inside. They act as a second line if a cell reading goes wrong. Keep them consistent with the cell values, otherwise one will always trigger before the other for no clear reason.
Balancing start
Daly boards balance passively and slowly. Balancing below the knee of the curve, around 3.40 V, does little because LiFePO4 voltages hardly differ there. A start voltage around 3.40 V with a difference of 10 to 30 mV is a usual compromise.
Temperature
Never charge LiFePO4 below 0 °C. Set the charge low-temperature protection at 0 to 5 °C. Discharge tolerates cold better; a limit around −10 to −20 °C is common. High-temperature limits near 50 to 55 °C protect both.
Currents
Charge and discharge current limits must match your cells, cables and the board rating, whichever is lowest. A limit set higher than the board can carry does not make the board stronger.
Check the result over a few weeks
Settings are confirmed by real cycles, not by the app screen. Daly Monitor records every cell, the balancing state and each protection event, so you see whether the pack reaches its limits, which cell triggers first, and whether balancing actually happens.
Common questions
Can Daly Monitor write these settings to the BMS?
No. It only reads. Change settings with the Daly app or PC software, then use the box to see how the pack behaves.
Why does my BMS keep cutting and reconnecting?
The recovery value is often too close to the limit. Widen the gap so the cell can settle before the BMS switches back.
Do these values work for NMC or LTO cells?
No. They are for LiFePO4 only. Other chemistries have very different voltage windows.
