Solar Power DIY Blog

When you have a string of cloudy days like we have just had here (and some good rain) the batteries will run down. I have deep cycle batteries as is typical of home electrical power set-ups. Most experts agree that you shouldn’t allow your batteries go down below 50%.  I prefer to never let the batteries go down below 70% before I intervene and start the generator.  I am usually tempted to put in just what I need for the next half a day, for overnight or whatever and settle for it to go to say 85%.  This may be OK for a few days.  But you need to be prepared to use some more fuel from time to time and fill the batteries right up, considering the usage over the next day or so coupled with the expected weather and the season.  It doesn’t take long and you get to know your system and what you should do.  Of course there is a chance that you have spent a lot of fuel and the next day you get a full day of sun.  But that means that batteries will then actually get filled properly and floated.  Even deep cycle batteries don’t like being even a little bit discharged for long periods of time.  By floated I mean trickle charged just to maintain the steady voltage, the batteries are full. Of course a wind generator may help but that’s a different topic.