As of today (BIOS 3.08), the package returned from ACPI method _BIX (\_SB.PC00.LPCB.BAT1._BIX) contains a Zero in field 0xB (Cycle Count)¹. This results in Windows being unable to report the cycle count via powercfg.
Proposal:
Read EC_MEMMAP_BAT_CCNT (0x015C) into STAX[0x0B]:
diff --git a/dsdt.dsl b/dsdt.dsl
index c48acc4..edd6055 100644
--- a/dsdt.dsl
+++ b/dsdt.dsl
@@ -75206,6 +75206,7 @@ DefinitionBlock ("", "DSDT", 2, "INSYDE", "TGL-ULT", 0x00000002)
Local3 |= (Local4 << 0x20)
STAX [0x11] = ToString (Concatenate (Local3, Zero), Ones)
STAX [0x08] = ^^EC0.M001 (0x014D)
+ STAX [0x0B] = ^^EC0.M005 (0x015C)
Local3 = ^^EC0.M005 (0x0160)
Local4 = ^^EC0.M005 (0x0164)
Local3 |= (Local4 << 0x20)
(This is from an ASL disassembly, and I do not expect that the source names match the dumped ones.)
¹ Apparently it moved in _BIX revision 1, but according to the FreeBSD project, “hardware vendors still stick to … _BIX rev.0”