diff --git a/findmy/reports/account.py b/findmy/reports/account.py
index 3c62f80..05ee744 100644
--- a/findmy/reports/account.py
+++ b/findmy/reports/account.py
@@ -593,12 +593,19 @@ class AsyncAppleAccount(BaseAppleAccount):
         return await self._login_mobileme()
 
     @require_login_state(LoginState.LOGGED_IN)
-    async def fetch_raw_reports(self, start: int, end: int, ids: list[str]) -> dict[str, Any]:
+    async def fetch_raw_reports(
+        self,
+        start: datetime,
+        end: datetime,
+        devices: list[list[str]],
+    ) -> dict[str, Any]:
         """Make a request for location reports, returning raw data."""
         auth = (
             self._login_state_data["dsid"],
             self._login_state_data["mobileme_data"]["tokens"]["searchPartyToken"],
         )
+        start_ts = int(start.timestamp() * 1000)
+        end_ts = int(end.timestamp() * 1000)
         data = {
             "clientContext": {
                 "clientBundleIdentifier": "com.apple.icloud.searchpartyuseragent",
@@ -606,13 +613,15 @@ class AsyncAppleAccount(BaseAppleAccount):
             },
             "fetch": [
                 {
-                    "startDateSecondary": start,
                     "ownedDeviceIds": [],
                     "keyType": 1,
-                    "startDate": start,
-                    "endDate": end,
-                    "primaryIds": ids,
-                },
+                    "startDate": start_ts,
+                    "startDateSecondary": start_ts,
+                    "endDate": end_ts,
+                    # passing all keys as primary seems to work fine
+                    "primaryIds": device_keys,
+                }
+                for device_keys in devices
             ],
         }
 
diff --git a/findmy/reports/reports.py b/findmy/reports/reports.py
index 2db3d90..df532fc 100644
--- a/findmy/reports/reports.py
+++ b/findmy/reports/reports.py
@@ -247,7 +247,7 @@ class LocationReportsFetcher:
         device: Sequence[HasHashedPublicKey | RollingKeyPairSource],
     ) -> dict[HasHashedPublicKey | RollingKeyPairSource, list[LocationReport]]: ...
 
-    async def fetch_reports(
+    async def fetch_reports(  # noqa: C901
         self,
         date_from: datetime,
         date_to: datetime,
@@ -269,46 +269,48 @@ class LocationReportsFetcher:
         as key, and a list of location reports as value.
         """
         key_devs: dict[HasHashedPublicKey, HasHashedPublicKey | RollingKeyPairSource] = {}
+        key_batches: list[list[HasHashedPublicKey]] = []
         if isinstance(device, HasHashedPublicKey):
             # single key
             key_devs = {device: device}
+            key_batches.append([device])
         elif isinstance(device, RollingKeyPairSource):
             # key generator
             #   add 12h margin to the generator
-            key_devs = {  # noqa: C420
-                key: device
-                for key in device.keys_between(
-                    date_from - timedelta(hours=12),
-                    date_to + timedelta(hours=12),
-                )
-            }
-
+            keys = device.keys_between(
+                date_from - timedelta(hours=12),
+                date_to + timedelta(hours=12),
+            )
+            key_devs = dict.fromkeys(keys, device)
+            key_batches.append(list(keys))
         elif isinstance(device, list) and all(
             isinstance(x, HasHashedPublicKey | RollingKeyPairSource) for x in device
         ):
             # multiple key generators
             #   add 12h margin to each generator
             device = cast("list[HasHashedPublicKey | RollingKeyPairSource]", device)
-            key_devs = {key: key for key in device if isinstance(key, HasHashedPublicKey)} | {
-                key: dev
-                for dev in device
-                if isinstance(dev, RollingKeyPairSource)
-                for key in dev.keys_between(
-                    date_from - timedelta(hours=12),
-                    date_to + timedelta(hours=12),
-                )
-            }
+            for dev in device:
+                if isinstance(dev, HasHashedPublicKey):
+                    key_devs[dev] = dev
+                    key_batches.append([dev])
+                elif isinstance(dev, RollingKeyPairSource):
+                    keys = dev.keys_between(
+                        date_from - timedelta(hours=12),
+                        date_to + timedelta(hours=12),
+                    )
+                    for key in keys:
+                        key_devs[key] = dev
+                    key_batches.append(list(keys))
         else:
             msg = "Unknown device type: %s"
             raise ValueError(msg, type(device))
 
         # sequence of keys (fetch 256 max at a time)
-        key_reports: dict[HasHashedPublicKey, list[LocationReport]] = {}
-        keys = list(key_devs.keys())
-        for key_offset in range(0, len(keys), 256):
-            chunk_keys = keys[key_offset : key_offset + 256]
-            chunk_reports = await self._fetch_reports(date_from, date_to, chunk_keys)
-            key_reports |= chunk_reports
+        key_reports: dict[HasHashedPublicKey, list[LocationReport]] = await self._fetch_reports(
+            date_from,
+            date_to,
+            key_batches,
+        )
 
         # combine (key -> list[report]) and (key -> device) into (device -> list[report])
         device_reports = defaultdict(list)
@@ -328,20 +330,22 @@ class LocationReportsFetcher:
         self,
         date_from: datetime,
         date_to: datetime,
-        keys: Sequence[HasHashedPublicKey],
+        device_keys: Sequence[Sequence[HasHashedPublicKey]],
     ) -> dict[HasHashedPublicKey, list[LocationReport]]:
-        logger.debug("Fetching reports for %s keys", len(keys))
+        logger.debug("Fetching reports for %s device(s)", len(device_keys))
 
         # lock requested time range to the past 7 days, +- 12 hours, then filter the response.
         # this is due to an Apple backend bug where the time range is not respected.
         # More info: https://github.com/biemster/FindMy/issues/7
         now = datetime.now().astimezone()
-        start_date = int((now - timedelta(days=7, hours=12)).timestamp() * 1000)
-        end_date = int((now + timedelta(hours=12)).timestamp() * 1000)
-        ids = [key.hashed_adv_key_b64 for key in keys]
+        start_date = now - timedelta(days=7, hours=12)
+        end_date = now + timedelta(hours=12)
+        ids = [[key.hashed_adv_key_b64 for key in keys] for keys in device_keys]
         data = await self._account.fetch_raw_reports(start_date, end_date, ids)
 
-        id_to_key: dict[bytes, HasHashedPublicKey] = {key.hashed_adv_key_bytes: key for key in keys}
+        id_to_key: dict[bytes, HasHashedPublicKey] = {
+            key.hashed_adv_key_bytes: key for keys in device_keys for key in keys
+        }
         reports: dict[HasHashedPublicKey, list[LocationReport]] = defaultdict(list)
         for key_reports in data.get("locationPayload", []):
             hashed_adv_key_bytes = base64.b64decode(key_reports["id"])