diff --git a/zephcore/adapters/sensors/SimpleLPP.h b/zephcore/adapters/sensors/SimpleLPP.h
index 441c1c4..96628d5 100644
--- a/zephcore/adapters/sensors/SimpleLPP.h
+++ b/zephcore/adapters/sensors/SimpleLPP.h
@@ -22,8 +22,8 @@
 #define LPP_TEMPERATURE         103   /* 2 bytes, 0.1°C signed */
 #define LPP_RELATIVE_HUMIDITY   104   /* 1 byte, 0.5% unsigned */
 #define LPP_BAROMETRIC_PRESSURE 115   /* 2 bytes, 0.1 hPa unsigned */
-#define LPP_VOLTAGE             116   /* 2 bytes, 0.01V unsigned */
-#define LPP_CURRENT             117   /* 2 bytes, 0.001A unsigned */
+#define LPP_VOLTAGE             116   /* 2 bytes, 0.01V signed */
+#define LPP_CURRENT             117   /* 2 bytes, 0.001A signed */
 #define LPP_ALTITUDE            121   /* 2 bytes, 1m signed */
 #define LPP_POWER               128   /* 2 bytes, 1W unsigned */
 #define LPP_DISTANCE            130   /* 4 bytes, 0.001m unsigned */
@@ -131,19 +131,26 @@ public:
      * @return Number of bytes written, or 0 on overflow
      */
     uint8_t addVoltage(uint8_t channel, float volts) {
-        uint16_t val = (uint16_t)(volts * LPP_VOLTAGE_MULT);
-        return addField2Unsigned(channel, LPP_VOLTAGE, val);
+        int16_t val = (int16_t)(volts * LPP_VOLTAGE_MULT);
+        return addField2Signed(channel, LPP_VOLTAGE, val);
     }
 
     /**
      * Add current reading
+     *
+     * Type 117 is signed in CayenneLPP (and in Arduino MeshCore, which uses
+     * the reference encoder), so a bidirectional monitor like the INA219 can
+     * report discharge as a negative value. Casting a negative float to an
+     * unsigned type is UB and saturates to 0 on the FPU, which silently
+     * reported 0 mA on every discharging node.
+     *
      * @param channel Channel number
-     * @param amps Current in amperes
+     * @param amps Current in amperes (negative = reverse flow)
      * @return Number of bytes written, or 0 on overflow
      */
     uint8_t addCurrent(uint8_t channel, float amps) {
-        uint16_t val = (uint16_t)(amps * LPP_CURRENT_MULT);
-        return addField2Unsigned(channel, LPP_CURRENT, val);
+        int16_t val = (int16_t)(amps * LPP_CURRENT_MULT);
+        return addField2Signed(channel, LPP_CURRENT, val);
     }
 
     /**
diff --git a/zephcore/app/CompanionMesh.cpp b/zephcore/app/CompanionMesh.cpp
index 874e984..241a930 100644
--- a/zephcore/app/CompanionMesh.cpp
+++ b/zephcore/app/CompanionMesh.cpp
@@ -1717,16 +1717,18 @@ int CompanionMesh::appendSelfTelemetry(uint8_t *reply, uint8_t permissions)
 				uint8_t ch = CH_SELF + 1;
 				for (int j = 0; j < pwr.num_channels; j++) {
 					if (pwr.channels[j].valid) {
-						// Voltage: [ch][LPP_VOLTAGE=116][2-byte 0.01V]
+						// Voltage: [ch][LPP_VOLTAGE=116][2-byte 0.01V signed]
 						reply[i++] = ch;
 						reply[i++] = 116;
-						uint16_t v = (uint16_t)(pwr.channels[j].voltage_v * 100);
+						int16_t v = (int16_t)(pwr.channels[j].voltage_v * 100);
 						reply[i++] = (v >> 8) & 0xFF;
 						reply[i++] = v & 0xFF;
-						// Current: [ch][LPP_CURRENT=117][2-byte 0.001A]
+						// Current: [ch][LPP_CURRENT=117][2-byte 0.001A signed]
+						// Signed: a bidirectional monitor (INA219) reports discharge
+						// as negative, and an unsigned cast saturates it to 0.
 						reply[i++] = ch;
 						reply[i++] = 117;
-						uint16_t c = (uint16_t)(pwr.channels[j].current_a * 1000);
+						int16_t c = (int16_t)(pwr.channels[j].current_a * 1000);
 						reply[i++] = (c >> 8) & 0xFF;
 						reply[i++] = c & 0xFF;
 						// Power: [ch][LPP_POWER=128][2-byte 1W]