diff --git a/firmware/src/battery.c b/firmware/src/battery.c
index c3dda12..780d9ed 100644
--- a/firmware/src/battery.c
+++ b/firmware/src/battery.c
@@ -71,7 +71,7 @@ void update_use_state(struct tracker_datapoint *dp)
 void update_charge_state(struct tracker_datapoint *dp)
 {
 #if RECHARGABLE_BATTERY
-  if (dp->solar > dp->battery) { /* power coming in */
+  if (dp->solar > 4.0) { /* power coming in */
     /* excess / charging */
     if (excess_count >= EXCESS_COUNT_MAX) { /* charge */
       battery_charge_state = BATTERY_CHARGING;
diff --git a/firmware/src/main.c b/firmware/src/main.c
index 8c607d8..787d2d9 100644
--- a/firmware/src/main.c
+++ b/firmware/src/main.c
@@ -48,7 +48,7 @@
 #include "sequencer.h"
 #include "thermistor.h"
 
-#define CALLSIGN	"UBSEDS15"
+#define CALLSIGN	"UBSEDS16"
 #define APRS_COMMENT	""
 
 /**