diff --git a/main/boards/zhengchen-1.54tft-ml307/zhengchen-1.54tft-ml307.cc b/main/boards/zhengchen-1.54tft-ml307/zhengchen-1.54tft-ml307.cc
index 7f563026..304361ba 100644
--- a/main/boards/zhengchen-1.54tft-ml307/zhengchen-1.54tft-ml307.cc
+++ b/main/boards/zhengchen-1.54tft-ml307/zhengchen-1.54tft-ml307.cc
@@ -212,7 +212,7 @@ public:
             power_save_timer_->SetEnabled(discharging);
             last_discharging = discharging;
         }
-        level = power_manager_->GetBatteryLevel();
+        level = std::max<uint32_t>(power_manager_->GetBatteryLevel(), 20);
         return true;
     }
 
diff --git a/main/boards/zhengchen-1.54tft-wifi/zhengchen-1.54tft-wifi.cc b/main/boards/zhengchen-1.54tft-wifi/zhengchen-1.54tft-wifi.cc
index edc8b501..b7e18bc6 100644
--- a/main/boards/zhengchen-1.54tft-wifi/zhengchen-1.54tft-wifi.cc
+++ b/main/boards/zhengchen-1.54tft-wifi/zhengchen-1.54tft-wifi.cc
@@ -228,7 +228,7 @@ ZHENGCHEN_1_54TFT_WIFI() :
             power_save_timer_->SetEnabled(discharging);
             last_discharging = discharging;
         }
-        level = power_manager_->GetBatteryLevel();
+        level = std::max<uint32_t>(power_manager_->GetBatteryLevel(), 20);
         return true;
     }