diff --git a/tools/battery/battery.py b/tools/battery/battery.py
index ed1098233..87742a9a7 100644
--- a/tools/battery/battery.py
+++ b/tools/battery/battery.py
@@ -203,18 +203,30 @@ def linux_hardware():
             sockets.add(p.group(1))
             cores.add((p.group(1), c.group(1)))
 
+    # Nominal (base) clock, never the boost clock: the model-name string, else cpufreq's own
+    # base_frequency (intel_pstate, kHz), else ACPI CPPC's nominal_freq (MHz; what AMD's
+    # acpi-cpufreq exposes instead - cpuinfo_max_freq on those boxes is the boost clock, not this).
     freq_ghz, freq_source = None, "unknown"
     m = re.search(r"@\s*([\d.]+)\s*GHz", model or "")
     if m:
         freq_ghz, freq_source = float(m.group(1)), "model name"
     else:
-        for name in ("base_frequency", "cpuinfo_max_freq"):
+        try:
+            freq_ghz = int(open("/sys/devices/system/cpu/cpu0/cpufreq/base_frequency").read()) / 1e6
+            freq_source = "base_frequency"
+        except (OSError, ValueError):
             try:
-                freq_ghz = int(open(f"/sys/devices/system/cpu/cpu0/cpufreq/{name}").read()) / 1e6
-                freq_source = name
-                break
+                freq_ghz = int(open("/sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq").read()) / 1e3
+                freq_source = "acpi_cppc"
             except (OSError, ValueError):
-                continue
+                pass
+
+    # Reported separately, and never as "nominal": cpuinfo_max_freq is the highest boost state.
+    max_boost_ghz = None
+    try:
+        max_boost_ghz = int(open("/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq").read()) / 1e6
+    except (OSError, ValueError):
+        pass
 
     mem_gib = None
     try:
@@ -226,8 +238,9 @@ def linux_hardware():
         pass
 
     return {"cpu_model": model or "unknown", "cpu_base_ghz": freq_ghz, "cpu_base_source": freq_source,
-            "sockets": len(sockets) or None, "physical_cores": len(cores) or None,
-            "threads": os.cpu_count(), "memory_gib": mem_gib, "gpus": gpu_hardware()}
+            "cpu_max_boost_ghz": max_boost_ghz, "sockets": len(sockets) or None,
+            "physical_cores": len(cores) or None, "threads": os.cpu_count(), "memory_gib": mem_gib,
+            "gpus": gpu_hardware()}
 
 
 def macos_hardware():
@@ -246,15 +259,16 @@ def macos_hardware():
         cores = f"{p_cores}P+{e_cores}E"
     mem = sysctl("hw.memsize")
     return {"cpu_model": model or "unknown", "cpu_base_ghz": freq_ghz, "cpu_base_source": freq_source,
-            "sockets": int(sysctl("hw.packages") or 1), "physical_cores": cores,
+            "cpu_max_boost_ghz": None, "sockets": int(sysctl("hw.packages") or 1), "physical_cores": cores,
             "threads": int(sysctl("hw.logicalcpu") or os.cpu_count()),
             "memory_gib": int(mem) / 1024 ** 3 if mem else None, "gpus": []}
 
 
 def hardware_info():
     """The run host's hardware, for the manifest: CPU model, nominal/base frequency (and where it
-    came from), physical cores, threads, sockets, memory, GPUs. Linux is detailed; macOS is a short
-    best-effort; anywhere else this is just empty, and the report says so."""
+    came from) plus max boost frequency separately, physical cores, threads, sockets, memory, GPUs.
+    Linux is detailed; macOS is a short best-effort; anywhere else this is just empty, and the
+    report says so."""
     try:
         if sys.platform == "darwin":
             return macos_hardware()
diff --git a/tools/battery/report.py b/tools/battery/report.py
index 2cc9e404c..69c0cdff9 100644
--- a/tools/battery/report.py
+++ b/tools/battery/report.py
@@ -293,8 +293,11 @@ def hardware_line(man):
     hw = man.get("hardware")
     if not hw:
         return "hardware: not recorded"
-    freq = f"{hw['cpu_base_ghz']:.2f} GHz nominal ({hw['cpu_base_source']})" if hw.get("cpu_base_ghz") else \
-        f"nominal frequency unknown ({hw.get('cpu_base_source', 'unknown')})"
+    freq_bits = [f"{hw['cpu_base_ghz']:.2f} GHz nominal ({hw['cpu_base_source']})" if hw.get("cpu_base_ghz")
+                 else "nominal frequency unknown"]
+    if hw.get("cpu_max_boost_ghz"):
+        freq_bits.append(f"{hw['cpu_max_boost_ghz']:.2f} GHz max boost")
+    freq = ", ".join(freq_bits)
     cores = f"{f(hw.get('physical_cores'), '{}')}C/{hw.get('threads') or '?'}T, {f(hw.get('sockets'), '{}')} socket(s)"
     mem = f"{hw['memory_gib']:.0f} GiB RAM" if hw.get("memory_gib") else "RAM unknown"
     gpus = ", ".join(f"{g['name']} ({g['memory']})" for g in hw.get("gpus") or []) or "none"