diff --git a/health/utils/libhealth2impl/HalHealthLoop.cpp b/health/utils/libhealth2impl/HalHealthLoop.cpp
new file mode 100644
index 0000000..3901a76
--- /dev/null
+++ b/health/utils/libhealth2impl/HalHealthLoop.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include <health2impl/HalHealthLoop.h>
+
+#include <android-base/logging.h>
+#include <hal_conversion.h>
+#include <hidl/HidlTransportSupport.h>
+#include <hwbinder/IPCThreadState.h>
+
+#include <health2impl/Health.h>
+
+using android::hardware::configureRpcThreadpool;
+using android::hardware::handleTransportPoll;
+using android::hardware::IPCThreadState;
+using android::hardware::setupTransportPolling;
+
+using android::hardware::health::V1_0::hal_conversion::convertFromHealthConfig;
+using android::hardware::health::V2_0::Result;
+
+namespace android {
+namespace hardware {
+namespace health {
+namespace V2_1 {
+namespace implementation {
+
+void HalHealthLoop::Init(struct healthd_config* config) {
+    // Retrieve healthd_config from the HAL.
+    service_->getHealthConfig([config](auto res, const auto& health_config) {
+        CHECK(res == Result::SUCCESS);
+
+        convertFromHealthConfig(health_config.battery, config);
+        config->boot_min_cap = health_config.bootMinCap;
+
+        // Leave screen_on empty because it is handled in GetScreenOn below.
+
+        // Leave ignorePowerSupplyNames empty because it isn't
+        // used by clients of health HAL.
+    });
+}
+
+void HalHealthLoop::Heartbeat(void) {
+    // noop
+}
+
+void HalHealthLoop::ScheduleBatteryUpdate() {
+    // ignore errors. impl may not be able to handle any callbacks, so
+    // update() may return errors.
+    Result res = service_->update();
+    if (res != Result::SUCCESS) {
+        LOG(WARNING) << "update() on the health HAL implementation failed with " << toString(res);
+    }
+
+    service_->getHealthInfo_2_1([this](auto res, const auto& health_info) {
+        CHECK(res == Result::SUCCESS)
+                << "getHealthInfo_2_1() on the health HAL implementation failed with "
+                << toString(res);
+        this->OnHealthInfoChanged(health_info);
+    });
+}
+
+int HalHealthLoop::PrepareToWait() {
+    return -1;
+}
+
+void HalHealthLoop::OnHealthInfoChanged(const HealthInfo& health_info) {
+    set_charger_online(health_info);
+    AdjustWakealarmPeriods(charger_online());
+}
+
+void HalHealthLoop::set_charger_online(const HealthInfo& health_info) {
+    const auto& props = health_info.legacy.legacy;
+    charger_online_ =
+            props.chargerAcOnline || props.chargerUsbOnline || props.chargerWirelessOnline;
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace health
+}  // namespace hardware
+}  // namespace android