Another batery question

[bc28036]

I have a old 61 Whitehouse with a '74 Johnson 50 hp O/B that I am going to be adding a second battery to to support some music in the boat. I like the easy way with a 1,2,B,off switch functioning as a manual isolator. After reviewing the stickies on dual battery setups i still have a nagging question. If I use one of the batteries hard to induce significant discharge or complete discharge, switch to the reserved battery, crank up the boat and go for a spin, I will NOT want to switch to the "both" position due to the discharged state of the first battery. I'm concerned about the big draw from the second (charged) battery to the first (discharged) battery cooking my battery cables and starting a fire. Unless I am greatly mistaken, the Johnson 50 O/B does not have much charging capabilities so it will not play a significant role in charging the discharged battery when the "both" position is selected. Am I just worrying to much or is my concern valid? Thanks.

 

[Silvertip]

Re: Another batery question

The purpose of the switch is to provide charging system "flexibility/versatility". The BOTH position would not be used in your "worrysome" scenario since you want the deeply discharged battery to get the maximum charge rate. However, even if you did use the BOTH setting, only if you had wire gauges that were too small would you have any "inrush" problems from the good battery to the deeply discharged so much of your concern is unfounded. When you have two vary different states of charge, use the charging system to get the weaker battery charged.

 

[Outsider]

Re: Another batery question

Am I just worrying to much or is my concern valid?

You won't start a fire, and you won't get much of a charge out of a 50. I reserve BOTH for emergency starts - which means I go home before shutting the engine down again ...