Need advice on adding a 2nd battery

[scott8058]

Hi, i have a 20ft bow rider and want to put a 2nd battery in for safety purposes and so that we can run the radio without worry on the sandbar but i have a few questions.

-What is the best bang for my buck as i don't have an unlimited budget

and

-i know you can get the switch to choose what battery you use but one does the alternator charge both or will i need to charge more and two will my alternator handle two batteries?

Here's the specs 5.7l merc 20ft, 1.5 i believe ratio, alpha one

Thanks for the help

 

[UncleWillie]

Re: Need advice on adding a 2nd battery

The least expensive option would be to get a battery sized to run the radio.
Better yet, Get one sized to start the motor.

Add a simple "1/2/Both" battery switch. (~$50)
Your Alternator (60-120amps) should be more than able to charge both batteries simultaneously, without issue.
Switch to "Both" while the motor is running and both batteries will be charged.
Switch to the Radio Battery when anchored, leaving the other battery in reserve for the restart.
Switch permits starting from either battery, or BOTH batteries if needed.

If you forget to switch to the radio battery when stoped ... Oops!
The switching can be automated with an ACR (Automatic Charging Relay) for an extra $100.

 

[scott8058]

Re: Need advice on adding a 2nd battery

Thank you very much thats what i wanted to hear!