diff --git a/gnss/1.0/IGnssBatching.hal b/gnss/1.0/IGnssBatching.hal
index 4d5affa..6f2dde6 100644
--- a/gnss/1.0/IGnssBatching.hal
+++ b/gnss/1.0/IGnssBatching.hal
@@ -136,7 +136,8 @@
 
     /**
      * Closes the interface. If any batch operations are in progress,
-     * they should be stopped.
+     * they must be stopped.  If any locations are in the hardware batch, they
+     * must be deleted (and not sent via callback.)
      *
      * init() may be called again, after this, if the interface is to be restored
      */
diff --git a/gnss/1.0/default/Gnss.cpp b/gnss/1.0/default/Gnss.cpp
index 19e22c2..a2a99a0 100644
--- a/gnss/1.0/default/Gnss.cpp
+++ b/gnss/1.0/default/Gnss.cpp
@@ -28,6 +28,8 @@
 std::vector<std::unique_ptr<ThreadFuncArgs>> Gnss::sThreadFuncArgsList;
 sp<IGnssCallback> Gnss::sGnssCbIface = nullptr;
 bool Gnss::sInterfaceExists = false;
+bool Gnss::sWakelockHeldGnss = false;
+bool Gnss::sWakelockHeldFused = false;
 
 GpsCallbacks Gnss::sGnssCb = {
     .size = sizeof(GpsCallbacks),
@@ -253,21 +255,62 @@
 }
 
 void Gnss::acquireWakelockCb() {
-    if (sGnssCbIface == nullptr) {
-        ALOGE("%s: GNSS Callback Interface configured incorrectly", __func__);
-        return;
-    }
-
-    sGnssCbIface->gnssAcquireWakelockCb();
+    acquireWakelockGnss();
 }
 
 void Gnss::releaseWakelockCb() {
+    releaseWakelockGnss();
+}
+
+
+void Gnss::acquireWakelockGnss() {
+    sWakelockHeldGnss = true;
+    updateWakelock();
+}
+
+void Gnss::releaseWakelockGnss() {
+    sWakelockHeldGnss = false;
+    updateWakelock();
+}
+
+void Gnss::acquireWakelockFused() {
+    sWakelockHeldFused = true;
+    updateWakelock();
+}
+
+void Gnss::releaseWakelockFused() {
+    sWakelockHeldFused = false;
+    updateWakelock();
+}
+
+void Gnss::updateWakelock() {
+    // Track the state of the last request - in case the wake lock in the layer above is reference
+    // counted.
+    static bool sWakelockHeld = false;
+
     if (sGnssCbIface == nullptr) {
         ALOGE("%s: GNSS Callback Interface configured incorrectly", __func__);
         return;
     }
 
-    sGnssCbIface->gnssReleaseWakelockCb();
+    if (sWakelockHeldGnss || sWakelockHeldFused) {
+        if (!sWakelockHeld) {
+            ALOGI("%s: GNSS HAL Wakelock acquired due to gps: %d, fused: %d", __func__,
+                    sWakelockHeldGnss, sWakelockHeldFused);
+            sWakelockHeld = true;
+            sGnssCbIface->gnssAcquireWakelockCb();
+        }
+    } else {
+        if (sWakelockHeld) {
+            ALOGI("%s: GNSS HAL Wakelock released", __func__);
+        } else  {
+            // To avoid burning power, always release, even if logic got here with sWakelock false
+            // which it shouldn't, unless underlying *.h implementation makes duplicate requests.
+            ALOGW("%s: GNSS HAL Wakelock released, duplicate request", __func__);
+        }
+        sWakelockHeld = false;
+        sGnssCbIface->gnssReleaseWakelockCb();
+    }
 }
 
 void Gnss::requestUtcTimeCb() {
@@ -541,8 +584,26 @@
     if (mGnssIface == nullptr) {
         ALOGE("%s: Gnss interface is unavailable", __func__);
     } else {
-        // TODO(b/34133439): actually get an flpLocationIface
+        hw_module_t* module;
         const FlpLocationInterface* flpLocationIface = nullptr;
+        int err = hw_get_module(FUSED_LOCATION_HARDWARE_MODULE_ID, (hw_module_t const**)&module);
+
+        if (err != 0) {
+            ALOGE("gnss flp hw_get_module failed: %d", err);
+        } else if (module == nullptr) {
+            ALOGE("Fused Location hw_get_module returned null module");
+        } else if (module->methods == nullptr) {
+            ALOGE("Fused Location hw_get_module returned null methods");
+        } else {
+            hw_device_t* device;
+            err = module->methods->open(module, FUSED_LOCATION_HARDWARE_MODULE_ID, &device);
+            if (err != 0) {
+                ALOGE("flpDevice open failed: %d", err);
+            } else {
+                flp_device_t * flpDevice = reinterpret_cast<flp_device_t*>(device);
+                flpLocationIface = flpDevice->get_flp_interface(flpDevice);
+            }
+        }
 
         if (flpLocationIface == nullptr) {
             ALOGE("%s: GnssBatching interface is not implemented by HAL", __func__);
@@ -550,7 +611,6 @@
             mGnssBatching = new GnssBatching(flpLocationIface);
         }
     }
-
     return mGnssBatching;
 }
 
diff --git a/gnss/1.0/default/Gnss.h b/gnss/1.0/default/Gnss.h
index 36947c1..63614fa 100644
--- a/gnss/1.0/default/Gnss.h
+++ b/gnss/1.0/default/Gnss.h
@@ -53,7 +53,6 @@
  * IGnssCallback interface to be passed into the conventional implementation of the GNSS HAL.
  */
 struct Gnss : public IGnss {
-    // TODO: Add flp_device_t, either in ctor, or later attach?
     Gnss(gps_device_t* gnss_device);
     ~Gnss();
 
@@ -109,11 +108,27 @@
     static void setSystemInfoCb(const LegacyGnssSystemInfo* info);
 
     /*
+     * Wakelock consolidation, only needed for dual use of a gps.h & fused_location.h HAL
+     *
+     * Ensures that if the last call from either legacy .h was to acquire a wakelock, that a
+     * wakelock is held.  Otherwise releases it.
+     */
+    static void acquireWakelockFused();
+    static void releaseWakelockFused();
+
+    /*
      * Holds function pointers to the callback methods.
      */
     static GpsCallbacks sGnssCb;
 
  private:
+    // for wakelock consolidation, see above
+    static void acquireWakelockGnss();
+    static void releaseWakelockGnss();
+    static void updateWakelock();
+    static bool sWakelockHeldGnss;
+    static bool sWakelockHeldFused;
+
     sp<GnssXtra> mGnssXtraIface = nullptr;
     sp<AGnssRil> mGnssRil = nullptr;
     sp<GnssGeofencing> mGnssGeofencingIface = nullptr;
diff --git a/gnss/1.0/default/GnssBatching.cpp b/gnss/1.0/default/GnssBatching.cpp
index 404b5da..95c5e60 100644
--- a/gnss/1.0/default/GnssBatching.cpp
+++ b/gnss/1.0/default/GnssBatching.cpp
@@ -1,4 +1,27 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "GnssHAL_GnssBatchingInterface"
+
 #include "GnssBatching.h"
+#include <Gnss.h> // for wakelock consolidation
+#include <GnssUtils.h>
+
+#include <cutils/log.h>  // for ALOGE
+#include <vector>
 
 namespace android {
 namespace hardware {
@@ -6,38 +29,189 @@
 namespace V1_0 {
 namespace implementation {
 
-GnssBatching::GnssBatching(const FlpLocationInterface* flpLocationIface) :
-    mFlpLocationIface(flpLocationIface) {}
+sp<IGnssBatchingCallback> GnssBatching::sGnssBatchingCbIface = nullptr;
+bool GnssBatching::sFlpSupportsBatching = false;
 
+FlpCallbacks GnssBatching::sFlpCb = {
+    .size = sizeof(FlpCallbacks),
+    .location_cb = locationCb,
+    .acquire_wakelock_cb = acquireWakelockCb,
+    .release_wakelock_cb = releaseWakelockCb,
+    .set_thread_event_cb = setThreadEventCb,
+    .flp_capabilities_cb = flpCapabilitiesCb,
+    .flp_status_cb = flpStatusCb,
+};
+
+GnssBatching::GnssBatching(const FlpLocationInterface* flpLocationIface) :
+    mFlpLocationIface(flpLocationIface) {
+}
+
+/*
+ * This enum is used locally by various methods below. It is only used by the default
+ * implementation and is not part of the GNSS interface.
+ */
+enum BatchingValues : uint16_t {
+    // Numbers 0-3 were used in earlier implementations - using 4 to be distinct to the HAL
+    FLP_GNSS_BATCHING_CLIENT_ID = 4,
+    // Tech. mask of GNSS, and sensor aiding, for legacy HAL to fit with GnssBatching API
+    FLP_TECH_MASK_GNSS_AND_SENSORS = FLP_TECH_MASK_GNSS | FLP_TECH_MASK_SENSORS,
+    // Putting a cap to avoid possible memory issues.  Unlikely values this high are supported.
+    MAX_LOCATIONS_PER_BATCH = 1000
+};
+
+void GnssBatching::locationCb(int32_t locationsCount, FlpLocation** locations) {
+    if (sGnssBatchingCbIface == nullptr) {
+        ALOGE("%s: GNSS Batching Callback Interface configured incorrectly", __func__);
+        return;
+    }
+
+    if (locations == nullptr) {
+        ALOGE("%s: Invalid locations from GNSS HAL", __func__);
+        return;
+    }
+
+    if (locationsCount < 0) {
+        ALOGE("%s: Negative location count: %d set to 0", __func__, locationsCount);
+        locationsCount = 0;
+    } else if (locationsCount > MAX_LOCATIONS_PER_BATCH) {
+        ALOGW("%s: Unexpected high location count: %d set to %d", __func__, locationsCount,
+                MAX_LOCATIONS_PER_BATCH);
+        locationsCount = MAX_LOCATIONS_PER_BATCH;
+    }
+
+    /**
+     * Note:
+     * Some existing implementations may drop duplicate locations.  These could be expanded here
+     * but as there's ambiguity between no-GPS-fix vs. dropped duplicates in that implementation,
+     * and that's not specified by the fused_location.h, that isn't safe to do here.
+     * Fortunately, this shouldn't be a major issue in cases where GNSS batching is typically
+     * used (e.g. when user is likely in vehicle/bicycle.)
+     */
+    std::vector<android::hardware::gnss::V1_0::GnssLocation> gnssLocations;
+    for (int iLocation = 0; iLocation < locationsCount; iLocation++) {
+        if (locations[iLocation] == nullptr) {
+            ALOGE("%s: Null location at slot: %d of %d, skipping", __func__, iLocation,
+                    locationsCount);
+            continue;
+        }
+        if ((locations[iLocation]->sources_used & ~FLP_TECH_MASK_GNSS_AND_SENSORS) != 0)
+        {
+            ALOGE("%s: Unrequested location type %d at slot: %d of %d, skipping", __func__,
+                    locations[iLocation]->sources_used, iLocation, locationsCount);
+            continue;
+        }
+        gnssLocations.push_back(convertToGnssLocation(locations[iLocation]));
+    }
+
+    sGnssBatchingCbIface->gnssLocationBatchCb(gnssLocations);
+}
+
+void GnssBatching::acquireWakelockCb() {
+    Gnss::acquireWakelockFused();
+}
+
+void GnssBatching::releaseWakelockCb() {
+    Gnss::releaseWakelockFused();
+}
+
+// this can just return success, because threads are now set up on demand in the jni layer
+int32_t GnssBatching::setThreadEventCb(ThreadEvent event) {
+    return FLP_RESULT_SUCCESS;
+}
+
+void GnssBatching::flpCapabilitiesCb(int32_t capabilities) {
+    ALOGD("%s capabilities %d", __func__, capabilities);
+
+    if (capabilities & CAPABILITY_GNSS) {
+        // once callback is received and capabilities high enough, we know version is
+        // high enough for flush()
+        sFlpSupportsBatching = true;
+    }
+}
+
+void GnssBatching::flpStatusCb(int32_t status) {
+    ALOGD("%s (default implementation) not forwarding status: %d", __func__, status);
+}
 
 // Methods from ::android::hardware::gnss::V1_0::IGnssBatching follow.
 Return<bool> GnssBatching::init(const sp<IGnssBatchingCallback>& callback) {
-    // TODO(b/34133439) implement
-    return false;
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching is unavailable", __func__);
+        return false;
+    }
+
+    sGnssBatchingCbIface = callback;
+
+    return (mFlpLocationIface->init(&sFlpCb) == 0);
 }
 
 Return<uint16_t> GnssBatching::getBatchSize() {
-    // TODO(b/34133439) implement
-    return 0;
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching interface is unavailable", __func__);
+        return 0;
+    }
+
+    return mFlpLocationIface->get_batch_size();
 }
 
 Return<bool> GnssBatching::start(const IGnssBatching::Options& options) {
-    // TODO(b/34133439) implement
-    return false;
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching interface is unavailable", __func__);
+        return false;
+    }
+
+    if (!sFlpSupportsBatching) {
+        ALOGE("%s: Flp batching interface not supported, no capabilities callback received",
+                __func__);
+        return false;
+    }
+
+    FlpBatchOptions optionsHw;
+    // Legacy code used 9999 mW for High accuracy, and 21 mW for balanced.
+    // New GNSS API just expects reasonable GNSS chipset behavior - do something efficient
+    // given the interval.  This 100 mW limit should be quite sufficient (esp. given legacy code
+    // implementations may not even use this value.)
+    optionsHw.max_power_allocation_mW = 100;
+    optionsHw.sources_to_use = FLP_TECH_MASK_GNSS_AND_SENSORS;
+    optionsHw.flags = 0;
+    if (options.flags & Flag::WAKEUP_ON_FIFO_FULL) {
+        optionsHw.flags |= FLP_BATCH_WAKEUP_ON_FIFO_FULL;
+    }
+    optionsHw.period_ns = options.periodNanos;
+    optionsHw.smallest_displacement_meters = 0; // Zero offset - just use time interval
+
+    return (mFlpLocationIface->start_batching(FLP_GNSS_BATCHING_CLIENT_ID, &optionsHw)
+            == FLP_RESULT_SUCCESS);
 }
 
 Return<void> GnssBatching::flush() {
-    // TODO(b/34133439) implement
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching interface is unavailable", __func__);
+        return Void();
+    }
+
+    mFlpLocationIface->flush_batched_locations();
+
     return Void();
 }
 
 Return<bool> GnssBatching::stop() {
-    // TODO(b/34133439) implement
-    return false;
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching interface is unavailable", __func__);
+        return false;
+    }
+
+    return (mFlpLocationIface->stop_batching(FLP_GNSS_BATCHING_CLIENT_ID) == FLP_RESULT_SUCCESS);
 }
 
 Return<void> GnssBatching::cleanup() {
-    // TODO(b/34133439) implement
+    if (mFlpLocationIface == nullptr) {
+        ALOGE("%s: Flp batching interface is unavailable", __func__);
+        return Void();
+    }
+
+    mFlpLocationIface->cleanup();
+
     return Void();
 }
 
diff --git a/gnss/1.0/default/GnssBatching.h b/gnss/1.0/default/GnssBatching.h
index ac3aa99..001c27d 100644
--- a/gnss/1.0/default/GnssBatching.h
+++ b/gnss/1.0/default/GnssBatching.h
@@ -6,7 +6,6 @@
 #include <hidl/MQDescriptor.h>
 #include <hidl/Status.h>
 
-
 namespace android {
 namespace hardware {
 namespace gnss {
@@ -35,8 +34,26 @@
     Return<bool> stop() override;
     Return<void> cleanup() override;
 
+    /*
+     * Callback methods to be passed into the conventional FLP HAL by the default
+     * implementation. These methods are not part of the IGnssBatching base class.
+     */
+    static void locationCb(int32_t locationsCount, FlpLocation** locations);
+    static void acquireWakelockCb();
+    static void releaseWakelockCb();
+    static int32_t setThreadEventCb(ThreadEvent event);
+    static void flpCapabilitiesCb(int32_t capabilities);
+    static void flpStatusCb(int32_t status);
+
+    /*
+     * Holds function pointers to the callback methods.
+     */
+    static FlpCallbacks sFlpCb;
+
  private:
     const FlpLocationInterface* mFlpLocationIface = nullptr;
+    static sp<IGnssBatchingCallback> sGnssBatchingCbIface;
+    static bool sFlpSupportsBatching;
 };
 
 extern "C" IGnssBatching* HIDL_FETCH_IGnssBatching(const char* name);
diff --git a/gnss/1.0/default/GnssUtils.cpp b/gnss/1.0/default/GnssUtils.cpp
index 82a516b..d9956d6 100644
--- a/gnss/1.0/default/GnssUtils.cpp
+++ b/gnss/1.0/default/GnssUtils.cpp
@@ -51,6 +51,28 @@
     return gnssLocation;
 }
 
+GnssLocation convertToGnssLocation(FlpLocation* location) {
+    GnssLocation gnssLocation = {};
+    if (location != nullptr) {
+        gnssLocation = {
+            // Bit mask applied (and 0's below) for same reason as above with GpsLocation
+            .gnssLocationFlags = static_cast<uint16_t>(location->flags & 0x1f),
+            .latitudeDegrees = location->latitude,
+            .longitudeDegrees = location->longitude,
+            .altitudeMeters = location->altitude,
+            .speedMetersPerSec = location->speed,
+            .bearingDegrees = location->bearing,
+            .horizontalAccuracyMeters = location->accuracy,
+            .verticalAccuracyMeters = 0,
+            .speedAccuracyMetersPerSecond = 0,
+            .bearingAccuracyDegrees = 0,
+            .timestamp = location->timestamp
+        };
+    }
+
+    return gnssLocation;
+}
+
 }  // namespace implementation
 }  // namespace V1_0
 }  // namespace gnss
diff --git a/gnss/1.0/default/GnssUtils.h b/gnss/1.0/default/GnssUtils.h
index fc2f547..38d4b2d 100644
--- a/gnss/1.0/default/GnssUtils.h
+++ b/gnss/1.0/default/GnssUtils.h
@@ -16,6 +16,7 @@
 #ifndef android_hardware_gnss_V1_0_GnssUtil_H_
 #define android_hardware_gnss_V1_0_GnssUtil_H_
 
+#include <hardware/fused_location.h>
 #include <hardware/gps.h>
 #include <android/hardware/gnss/1.0/types.h>
 
@@ -31,6 +32,12 @@
  */
 GnssLocation convertToGnssLocation(GpsLocation* location);
 
+/*
+ * This method converts an FlpLocation struct to a GnssLocation
+ * struct.
+ */
+GnssLocation convertToGnssLocation(FlpLocation* location);
+
 }  // namespace implementation
 }  // namespace V1_0
 }  // namespace gnss