Coach Battery Replacement

[Cary Rodriguez]

Good Day Beaver Heads!

     Almost sounds like a Grateful Dead post.     The wife and I picked up a 2003 Beaver Monterey Ventura a few months back and are replacing aged items a little at a time.  I am looking to replace my coach batteries and was wondering if 2 of these would be a good choice: Super Start Marine Battery Group Size 27 - 27DCM from O'reilly's.  I currently have four 6V batteries but looking to simplify things. Many thanks.

Cary

[Bryan Beamon]

Cary, the amp hours on a group 27 battery are 72 to 90 amp hours while a good 6volt wet cell is 210AH . Plus the lead plates in a 6volt battery ate much more robust. The battery bank of 4 6volt is 400AH+ which is more the double the two 12 volt marine batteries. Unless there are other considerations suggest you stay with the 4 6volt battery set up

[Joel Ashley]

Bryan’s right that you want 6v deep cycles for their total amp hour capacity.  Some thoughts:
1). Take a couple clear photos of your current battery wiring configuration and make a paper diagram, so you can correctly reinstall wires;  unplug the Coach and throw a dark cloth over the solar panel to avoid sparking when handling battery connectors;
2). Consider getting the 6v deep cycle Interstates that Costco sells - they are one of the better deals;
3). To be finally rid of corrosion and water top-ups like I am, AGM house batteries should be on your radar despite their extra expense.  Just be sure your inverter and solar chargers can work with them.

Joel

[Cary Rodriguez]

Bryan and Joel,

     Many thanks for your replies.  I will go ahead and stick with the 4 6V batteries.  I have already taken photos of the wiring and also made a drawing of the battery layout just in case.  Thanks again.

Cary

[Fred Brooks]

  Cary,
  Here are some more considerations as you enjoy your adventure. When you connect 2 deep cycle 6 volt batteries in series you will double the voltage to 12 volts but not the amperage rating. So your system with 4 -6 volt deep cycle batteries will be 2- 12volt batteries in parallel with 420 to 440 amp hour rating. A fully charged 12volt system resting will yield 12.8 volts. These batteries should never be discharged below 50% of their capacity which is 12.3 volts. Failure to do so will damage their life span. Another consideration is Peukerts law when discharging batteries. When discharging lead-acid batteries the rule is between 25 and 30% loss of capacity dependent on rate of discharge. If you operate within these parameters the batteries will last 4 to 5 years if you do the maintenance. Make sure you cover any solar panels when you disconnect the batteries. Failure to do so may damage the solar voltage regulator. Hope this helps, and welcome to the forum. Fred

[Cary Rodriguez]

Hey Fred,

    Many thanks for the recommendations.  I really appreciate it.

Cary