RV FEATURE
This is great but what does it all mean in the real world ?
First , you ’ re unlikely to be running just one television . You ’ re going to want to run all sorts of devices for differing lengths of time . This will ultimately determine how much battery capacity you are going to need .
Let ’ s look at some of the more common 12V electrical devices and how many amps they draw .
Device |
Approximate current draw |
White interior ceiling LED lamp |
0.5A each |
Exterior LED floodlight |
1A each |
24in 12V flatscreen TV |
5A |
Compressor fridge 12V |
6A ( while the compressor is running ) |
Water pump |
6A |
USB charger outlet |
2A |
Car / marine stereo system |
20A ( peak ) |
Each of those devices will be run for varying lengths of time . For instance , you might have three exterior floodlights but you might only run them for two hours a night . While they are on , they are drawing 3A each and , over 2 hours , each will take 6Ah out of your battery .
On the other hand , you will likely be running your fridge continuously and , as noted , the compressor draws 6A . However , fridges don ’ t need the compressor to run all the time . It automatically turns on and off depending on the setting and the ambient temperature . This is called a duty cycle . In cool weather , the compressor might run for only 30 minutes every hour and use 3Ah per hour . Over a 24-hour period , that works out to ( 24x3 ) 72Ah in total .
/ 19