diff --git a/apps/debug_menu.c b/apps/debug_menu.c
index 1288d9a..fc9424a 100644
--- a/apps/debug_menu.c
+++ b/apps/debug_menu.c
@@ -1495,7 +1495,7 @@ static bool tsc2100_debug(void)
 static bool view_battery(void)
 {
     int view = 0;
-    int i, x, y;
+    int i, x, y, ygraph, ygraph_old;
     unsigned short maxv, minv;

     lcd_setfont(FONT_SYSFIXED);
@@ -1521,13 +1521,15 @@ static bool view_battery(void)
                          minv / 1000, minv % 1000, maxv / 1000, maxv % 1000);

                 x = 0;
+                ygraph_old = LCD_HEIGHT-1;
                 for (i = BAT_LAST_VAL - 1; i >= 0; i--) {
                     y = (power_history[i] - minv) * BAT_YSPACE / (maxv - minv);
+                    ygraph = MIN(MAX(LCD_HEIGHT-1 - y, 20), LCD_HEIGHT-1);
                     lcd_set_drawmode(DRMODE_SOLID|DRMODE_INVERSEVID);
-                    lcd_vline(x, LCD_HEIGHT-1, 20);
+                    lcd_vline(x, LCD_HEIGHT-1, 20); /*clear space */
                     lcd_set_drawmode(DRMODE_SOLID);
-                    lcd_vline(x, LCD_HEIGHT-1,
-                              MIN(MAX(LCD_HEIGHT-1 - y, 20), LCD_HEIGHT-1));
+                    lcd_vline(x, ygraph_old, ygraph);
+                    ygraph_old = ygraph;
                     x++;
                 }