diff --git a/app/models/reading.rb b/app/models/reading.rb
index 066909f..230186e 100644
--- a/app/models/reading.rb
+++ b/app/models/reading.rb
@@ -181,7 +181,7 @@ class Reading < ActiveRecord::Base
         p "Battery is now at %s kwh" % @@battery_kwh
         return kwh
       else
-        old_kwh = @battery_kwh
+        old_kwh = @@battery_kwh
         @@battery_kwh = BATTERY_MAX_KWH
         p "Battery is now at %s kwh" % @@battery_kwh
         return (BATTERY_MAX_KWH-old_kwh)
@@ -231,7 +231,7 @@ class Reading < ActiveRecord::Base
           else
             easy_usage_rate, easy_return_rate = easy_energy_rate(formatted_hour)
             # if rate > charge_rate + 0.05 || more than 5.0 kwh then discharge_battery
-            if @battery_kwh > 5.0 || (easy_usage_rate.to_f > (low_usage_rate.to_f + 0.05)) 
+            if @@battery_kwh > 5.0 || (easy_usage_rate.to_f > (low_usage_rate.to_f + 0.05)) 
                usage_kwh -= discharge_battery(usage_kwh)
             end   
           end    
@@ -250,7 +250,7 @@ class Reading < ActiveRecord::Base
                     hour_diff[:total_kwh_produced_low],
                     usage_kwh,
                     return_kwh,
-                    @battery_kwh,
+                    @@battery_kwh,
                     easy_usage_rate, 
                     easy_return_rate,
                     easy_cost_with_battery,