adding a secondary battery on my v/p 4.3 (430b) engine

[mcw]

hi

Is there an advantage of installing secondary battery in to my boat, ive finished the basic inshore electrics and this is next job.

I currently have a marine 110amp battery that i use for starting and all the auxiliaries like radio, depth sounder, light, cabin lights and the rest and never had an issue with starting or low battery levels come the end of the day this is switched off via a battery isolator switch

I have been give a nearly new 110 leisure battery is it worth the extra weight to the boat??? to install this battery and use it as my main battery for the auxiliaries and keep the marine battery for starting only.

What is the best basic way to install the secondary battery, or should i not bother, having two large batteries will add alot more weight to the back of the boat.

what are the advantages or disadvantages.

 

[RicardoMarine]

Can you rope start your engine?
If you can, then there is no need for a "reserve" battery bank.

If you cannot rope start it, then I'd consider installing an MBSS (main battery selector switch), and a second battery bank.
#1.... will be a dedicated cranking battery.
#2.... will be a Deep Cycle battery or Batteries (plural).

The type of battery best suited is different between these two uses.

Crank on #1, warm engine and charge, switch to #2 until you need to use the #1 "reserve" bank again.

This is an image that I use occasionally.
If need be, tailor it to fit your needs.