Deep Cycle Vs. Starting Battery

[Ringo]

I have 2 deep cycle batteries on my boat that are installed in series for 24V output. One of them is connected to the main engine (50hp Honda) but my understanding is that the main engine doesn't charge the deep cycles and in fact it can damage them. I just use the deep cycle for typical accessories (sounder, downrigger, courtesy lights, etc.) and usually charge them with a smart charger when back on shore.
I did a little bit of research and found the marine batteries with dual starting & deep cycle feature. Would they be a good replacement for the deep cycle that's currently feeding my engine? or should I invest in a starting 12V battery for starting my main and attach the accessories to the other deep cycle?

 

[scott craven]

I run a single deep cycle battery for starting as well as electronics and downrigger's.
Main has always charged without a problem.
they usually last 5-6 years.

 

[Fisherman Rob]

Interesting that you have two 12v wired in series. I think normally they would be wired in parallel. I would have thought wiring in series would overload the system that is expecting about 12-14 volts? As to your question, given that your 50 probably doesn't have a huge draw when starting (as compared to say a 200) , a combo battery would be ok.

 

[Corey_lax]

I think you should definitely get a battery switch. Never heard of anyone running batteries like that. My main doesn't have a rectifier and my vhf shuts down at close to 16 volts so not sure how you still have electronics. Since I've switched some electronics recently, this hasn't been an issue

Battery 1 for me is an interstate deep cycle/starting. Runs the main motor, depthsounder, vhf, radio, etc. Battery 2 is a can tire deep cycle which will soon be replaced by another interstate. Battery 2 starts the kicker and runs the downriggers. My kicker charges as well

 

[1marko]

deep cycle has thicker plates. takes longer
to charge as well as discharge. starting
batteries have thinner plates for a higher
amperage quick discharge for starting
and quick recovery.... combos are
somewhere in between.

 

[fishin solo]

I run 2 deep cycles no problems starting my vrod 350 or charging always have lots of accessories on and no problems

 

[Franko Manini]

I run one standard battery for starting, and a deep cycle for long, slow discharge requirements (sounder, bilge pump, downriggers, etc.). When I'm running, both batteries go on charge. When I'm fishing, I run the deep cycle, and when I'm at the dock, the deep cycle is on. If I leave the boat moored for a while (like a week), I leave both batteries on.

 

[bigbruce]

Same as Franko. I have a Blue Seas ACR to ensure the starting battery is always charged. All but the engine (5l VP) runs off the deep cycle.

 

[Ringo]

There seems to be a variety of inputs, which I appreciate. I use 2 deep cycle batteries for my 24 trolling motor when I'm fishing for lake trouts/kokanees. I don't use the electric motor in salt water. What I've heard about the deep cycle batteries is that the main engine alternator doesn't have enough cycles to charge the battery on an average outing (6-7 hours) with the electronics all on. Is this true?
I use the main engine for trolling and don't have a gas kicker on my boat but when back on the dock, the charger shows the deep cycle is in 60% (the one that's connected to the main). I don't want the hassle of dealing with dead batteries and on the water so, If I can have a starting battery that's connected to the main engine and one deep cycle connected to electronics and DR, I should be OK??
WRT the comment on a switch, I bought one a couple of years ago but couldn't find enough space to install it in my battery compartment. I guess I just need to aim for a bigger boat!
I bought these two deep cycles new in 2015 and have kept them charged after each outing so they should still be in a good shape. Don't want to spend $$ on a 3rd battery if it's really not needed.

 

[Fisherman Rob]

Ah... you are using a 24v electric lake trolling motor. I assumed you had somehow rigged your boat and engine for 24 volts!

 

[bullyjack]

I run 2 deepcycles on a switch. 1 is my starting battery only, 2 runs eveything else, electronics, downriggers, lights havn't had a problem yet.

 

[Canso]

Ah... you are using a 24v electric lake trolling motor. I assumed you had somehow rigged your boat and engine for 24 volts!

You can still pull 12 volts from a 24volt setup.
Use the first battery (ground side) as 12 volts,

 

[Stosh]

I've run 2 deep cycle batteries with the battery switch set at both batteries on for the past 17 yrs (not the same batteries).
Seems to work ok for me. I run a 200 hp Honda, keeps the batteries charged up just fine.
Stosh

 

[ziggy]

Looking at replacing my house battery shortly. Any thoughts on the best type/brand ( so many different types now)and supplier on the South Island. Currently I run a separate starter and deep cycle house battery.

 

[fishin solo]

Costco

 

[Fox]

2 deep cycles with a perko switch. Optima blue tops, 8 years old......maybe it's time for new ones. I think they paid their dues. Will be buying blue tops again.

 

[Catch 22]

Costco. Series 27 $130. I have 2, no issues. I run 2 dowriggers, gps/ fishfinder, stereo all day. My kicker doesn't charge and I'm able to start main at the end of the day on that same battery. 2nd is there as a backup. I have a switch.

 

[ericl]

Having a dedicated starting battery (only used to start the engine) is a standard "best practice" in boating. Your engines charging system is designed to charge a starting battery, not a deep cycle battery. Charging a deep cycle battery with a standard alternator/regulator will lead to premature battery failure. If the boat is a "day boat", I'd add a deep cycle battery sized so that you can use it the whole day without charging, then charge it with a plug-in deep cycle charger on shore. An emergency switch to allow using the deep cycle for starting the engine would be a great idea.
Totally automated systems that will charge both batteries at the same time are available from www.balmar.net but they are expensive.

 

[Gear'n'beer!]

Another vote for Costco.......100 month prorated warranteep. Any battery more than 5 years old is on borrowed time. Take both back at 5 years and get about $130 bucks back. Pays for one battery.