185 Sport - Battery Selections

MarkD

Member
Oct 5, 2006
355
Hudson River
Boat Info
1990 35' Sundancer
Engines
twin 454 inboards
I am thinking about adding some extra amp hours for my existing 2008 185 Sport boat. I currently have the existing starting battery which is 1 year old and in fine shape. I was contemplating some replacement options to get some additional capacity for when we anchor out for the day, play the radio, or add a second bilge pump for safety. My options:

1) Completely replace the existing battery with a combo style Group 24 Deep Cycle/Starting battery. This should afford some extra capacity without taking up alot of space. Storage is at a premium in this boat btw.

2) Add a second battery (same group 24 deep cycle) and a battery switch.

Anybody have opinions on what is the way to go?
 
2nd Battery and Switch is the only way to go in my opinion.

You didn't have a 27TM in there? Thats what I put in all my new Sea Ray's, mostly because thats the size of the tray:grin:

I suppose we order ours that way.
 
My owner's manual recommends a group 31 size battery, while my boat came with a group 27. MarkD's boat came with a group 24. Why all the difference and which is right??
 
SR.. does the 27TM have the same footprint as a group 24? I agree with you on the second battery, however space is at a premium in these things. So is weight distribution.

paul, your owners manual recommends a group 31???? Holy cow! that is a huge battery. I have those on my big boat. they are super heavy as well. I would say a group 27 would be a decent compromise for our type of boat & engine combo.
 
One other question. can someone provide a "proper" wiring diagram or elaborate as to how to hook a second battery and switch up?
 
No the 27 is bigger by a inch or so. A 31 is WAY to big for a 185 and would probably cause some severe listing. I really only use 24s on smaller (100hp and down) O/B's

Simple hook up....

Run a wire from the main starter stud to the common stud on the back of the switch, along with any accessories that you want on a switch.

Run a wire from Battery 1+ to battery 1 post on the switch.
Run a wire from Battery 2+ to battery 2 post on the switch.

Run a wire from ground to ground on the batteries.

I'd use 0-4 gauge wire, solder and heat shrink the crimps.
 
Last edited:
SR, thanks again for the info. I will probably end up with a group24 deep cycle as you mentioned since I really have so few house battery needs. I also think I will probably keep the batteries on the same side to avoid any long runs. I recall Wesley doing that with his 185 sport as well (in a prior thread).

One last question on the type of switch to install..... Would I require an AFD (alternator field dosconnect) type switch or would the standard one work ok???
 
Regular switch, hook up your alternator feed wire to the main stud on your starter.

Try to remember to use 1 battery at a time, the alternator cannot deliver an equal charge when both posts are closed on the switch "both".
 
SR Tech, Thanks for the good information you provided. I'm will be adding a group 27 battery and a perko switch. Do the original battery cables (positive and negative) stay on the original battery?

My amps are currently hooked up to the original battery. Should I hook them up to the common stud on the back of the switch if I want to be able to run the stereo on battery 2?
 
Yes, everything you want switched will go to the common stud on the back of your battery switch. Then you will be able to choose which battery you want to power your needs.

I'm not really sure what you mean by keep the cables on the orginal battery...:huh: Elaborate further please:grin:
 
I mean the factory battery cables that are connected to the battery now. Do I leave them connected and not touch them? Based on your instructions, I would:

Run a wire from the starter stud to the common on the back of the switch
Run a wire from Battery 1+ to battery 1 post on the switch.
Run a wire from Battery 2+ to battery 2 post on the switch.
Run a wire from ground to ground on the batteries

Or can it be done this way (with no need for a wire from starter stud to common)

Disconnect factory (+) from battery 1 and connect to Common on the back of the switch
Run a wire from Battery 1+ to battery 1 post on the switch.
Run a wire from Battery 2+ to battery 2 post on the switch.
Run a wire from ground to ground on the batteries
 
Technically yes....

Your factory + battery cable is allready run to the starter. So your second theory is correct.

It depends where you mount your switch, you may not have enough wire.

The only factory wire that does move is going to be your main ground to the motor
 
Last edited:
Thank you for the valuable info, much appreciated. When spring rolls around, I'll be ducking into the engine bay to explore my options.

Is there a charging wire from the alternator that also connects to battery 1+? Is this different/separate from the starter wire? Thanks again.
 
MarkD
You may want to think about a battery combiner. This allows both batterys to charge without moving the switch. This does not replace the switch but saves you from remembering to move the switch from one battery to the next to charge. I installed this one last year and never had a problem.
http://www.yandina.com/c100InfoR3.htm
 
Try to remember to use 1 battery at a time, the alternator cannot deliver an equal charge when both posts are closed on the switch "both".
I agree you need to use one battery for house loads to avoid draining the start battery. There is nothing wrong with charging 2 batteries in parallel. The alternator puts out ~13.8 volts regardless of one or two batteries. Each battery gets fully charged assuming the engine in run for long enough.
 

Forum statistics

Threads
112,950
Messages
1,422,865
Members
60,932
Latest member
juliediane
Back
Top