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();
 }