BM3451 to protect a Parkside battery

[Romain]

Hi,

I'm using a Parkside 5S 20V battery from LIDL to power a DPS3005 as a portable power station and I'm very happy with it.
This is the 3d model I printed: https://cults3d.com/en/3d-model/tool/parkside-x20v-team-rd-dps3005-portable-100w-power-supply

I'm after an under-voltage protection that's normally performed by the power tool, not the battery itself. The battery only includes the balancing circuit.
I was hoping I could use an AE module for that. This is what I bought: https://www.aliexpress.com/item/32889959726.html

Unfortunately since I only have access to the battery 5S 20V output, I cannot tap into the balancing points, which makes the BM3451 unhappy:

Breaking wire protection
When one or multi wires of VC1, VC2, VC3, VC4 and VC5 are detected cut from the batteries by the
BM3451 chip, the IC will consider it enters a state of breaking wire, then CO will be in high resistance and
DO will turn to GND level, then the IC enters low consumption state.
When the breaking wires are connected correctly again, the IC will exit breaking wire protection.
Specially attention, regardless one chip application or multi-chip application, the GND pin must not be open
from the battery, or the IC cannot operate normally, and it cannot protect correctly.

So my question is simple, do you have a suggestion for an under-voltage protection for a 20V battery up to 50A?

[Chalcogenide]

You could use a micropower reference and a micropower comparator comparing said reference to a voltage divider from the battery to drive an external MOSFET. TI's TLV6713 includes both the reference and the comparator, although it has an open drain output which might not be what you want.