Battery Question - 2017 G23

[XBIGPUN66]

We upgraded to two group 31 batteries and it makes a significant difference in reserve time with the stereo at the tie up

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[Kmayotte]

The only reason to install 1 deep cycle is if you plan on draining the battery down significantly meaning sitting somewhere with the sound system on for hours or leaving the boat in the water with the bilge pump "on". If you are not draining the deep cycle you are better with a standard lead-acid. If you are partially draining then an AGM is a good choice plus they charge faster when you start the engine. Personally, I use a deep cycle for trolling motors only and hate them for other uses and they suck as starting batteries. However, I also don't crank music for significant periods with the engine off. I am not a fan of music you cannot talk over.

It's also a bad idea to combine batteries especially if they are of different types or different ages without a combiner with start isolation while charging from the engine. If left combined, batteries will rob each other until they reach the same potential. Conversely, if you are charging you will keep forcing juice into a good battery if the other is bad.

It's Science!

Very helpful thank you. We do leave the boat in the water for extended periods with the bilge "on".
Looks like I'll be searching for two Group 24 AGM batteries. Thanks!

[kylant]

i think one of my batteries is toast. just posted another thread about this.
my boat has DEKA 24M7 batteries stock
these are group 24, but are they lead/acid or AGM? They don't say. DEKA website doesn't say. all this is foreign to me.
also will the on-board charger on the boat be able to charge AGM batteries if the stocks are not and I "upgrade"?
i have attached pics B60EBDF5-365C-49C4-9C47-7DEB737A7219.heic 01AC0762-493C-404F-9213-015F08D43CA1.heic

[kylant]

so back to this. looks like i will have to replace my batteries.
i think i am going to go agm.
just want to make sure the onboard charger is compatible. it says agm right on it.

is it??
thanks

[Tony E]

The only reason to install 1 deep cycle is if you plan on draining the battery down significantly meaning sitting somewhere with the sound system on for hours or leaving the boat in the water with the bilge pump "on". If you are not draining the deep cycle you are better with a standard lead-acid. If you are partially draining then an AGM is a good choice plus they charge faster when you start the engine. Personally, I use a deep cycle for trolling motors only and hate them for other uses and they suck as starting batteries. However, I also don't crank music for significant periods with the engine off. I am not a fan of music you cannot talk over.

It's also a bad idea to combine batteries especially if they are of different types or different ages without a combiner with start isolation while charging from the engine. If left combined, batteries will rob each other until they reach the same potential. Conversely, if you are charging you will keep forcing juice into a good battery if the other is bad.

It's Science!

2017 G23. My battery switch is 1 & 1/2 combined (can't isolate 2). # 1 (starting) battery has gone bad. When I replace, wondering if the ideal configuration is # 1 battery starting, # 2 battery deep cycle. When starting the boat, I start with only # 1 (starting battery), then when trolling, change to #1/2 combined, which will bring in deep cycle battery?

Does this make the most sense or is there a better configuration? Both starting batteries? Should I replace both batteries at same time? (#2 battery is good, replaced 1 year ago).

[GMLIII]

Tony E when I replaced both of my batteries, I purchased AGM batteries vs lead acid and could not be happier, but there again on this forum that is like asking which boat cleaner you use. The lead acid lovers will attack the AGM users and vice versa. Like you my battery switch went bad but it was replaced under warranty. There has been a history of these switches failing on these boats. Hope you are well.

[bturner]

If you don't already have a battery isolator I would highly recommend going this direction. Doing so will mean the isolator will take care of which battery needs and will get charged while underway. Blue Seas makes a complete kit that is both inexpensive (relatively speaking) and easy to install (once again relatively speaking). If not you're going to be guessing at battery charge level and manually switching from 1 to 2 to try and balance charge level. My understanding is that 1+2 is to only be used when absolutely necessary. If you have a dead cell in one of the batteries and are running 1+2 it will kill the good battery.

https://www.amazon.com/dp/B000RZNP5K...language=en_US

As to batteries..... I'll agree with GML and stay away from the battery holy war. I buy AGM for multiple reasons but you are welcome to do whatever you please. Part of the reason I typically replace lead/acid batteries in pairs if for the situation you're in right now. You replaced one last year and here you are with battery issues this year. Personally I'd be hard pressed to replace a 1 YO battery unless I was going to go another direction on the type. If you decide to do AGM they absolutely do both. If not, you are where you are and I'd do just the one. Unless you're doing stereo wars on the weekends most any battery will do. I tend to purchase the mixed use batteries and did so with my AGM purchase but then again I'm not doing any camping or jamming at the island for 4 hours at a crack either.

Whatever you decide to do make sure you get your switch in order before moving forward with any battery purchase.

[Tony E]

2017 G23. My battery switch is 1 & 1/2 combined (can't isolate 2). # 1 (starting) battery has gone bad. When I replace, wondering if the ideal configuration is # 1 battery starting, # 2 battery deep cycle. When starting the boat, I start with only # 1 (starting battery), then when trolling, change to #1/2 combined, which will bring in deep cycle battery?

Does this make the most sense or is there a better configuration? Both starting batteries? Should I replace both batteries at same time? (#2 battery is good, replaced 1 year ago).

Follow up on my above question. I discussed with the service tech at my Nautique dealer. They contacted Nautique factory techs and Nautique recommends using starting batteries for both sides (not deep cycle). Should be at least 800 cold cranking amps, 1000 cranking amps. You do not need to replace both batteries at the same time; replace them individually when they are expired.

Some knowledge others might find helpful:

• My 2017 G23 came stock with size 24 batteries, lead/acid.
• Battery selector switch is # 1 (port side) or #1/2 (both batteries). # 2 is starboard side.
• I use the onboard ProMariner 12 charger when I have the chance to plug it in (it's dry docked in a marina so I only plug it in at end of season when I'm servicing it).
• I pull the batteries in the off season and use the NoCo charger in my home to keep them optimized over the winter.
• I have used an Interstate Battery size 24 starting type (Model 24M-XHD) with good results.
• My dealer used the Deka Marine Master battery a few years ago. This battery lasted 2 seasons and died after 2 months of use this 3rd season despite me having it charged/conditioned over the winter. I've read good reviews on the Interstate Batteries so we'll so how these go over

Hope this helps someone.

[R0CKETMAN]

‘15 G23

- Replacing both batteries

- We do anchor and run radio for hours

- Have the “stock” Perko switch 1-2 1/2

Considering “Starting” for 1 & “deep cycle” for 2

would turn switch to 2 / “deep cycle” when anchored

Thoughts?

[bturner]

Unless I'm misunderstanding the electrical configuration of these later year model boats, they did not come with a battery isolator, which I find a bit perplexing. In 2015 that was a top end boat that cost a good chunk of cash and if I understand this correctly the dual battery option (or maybe it was standard in this boat, IDK) was a simple switch? That's a bit nuts to me but......

Oh well, back to the thread post. As stated in previous replies throughout this thread this is going to be a "what is the best oil" question with plenty of strong opinions. If it were my boat I would.....

• Verify the configuration of the battery set up and see if you have an isolator. My personal experience with manual 1 - 2 - 1+2 switches has been, not so good as you're always guessing as to the condition of the batteries and having to switch them over manually. If you don't currently have an isolator installed I would install one as my first action to address your battery configuration.
• Next, I would want to know exactly what circuits are connected to which battery. I would expect that the stereo is on one battery and most if not all the other circuits are on the other but that would be a very basic assumption that I wouldn't want to take for granted. I like to keep my starting circuit off the stereo battery so on those long days at the sand bar with the stereo won't effect my ability to go home at the end of the day.
• If you have the ability to charge your batteries at your dock, I would install a charger in the boat. If you're doing a lot of sitting then driving a short distance home, it's doubtful you're going to charge the batteries fully on that short ride home.
• Then there's the age old what battery question. I'm in the AGM camp. I would (and have for years) buy the biggest, best AGMs that will fit your application and not worry about deep cycle and starting battery types. There's a reason the bass boat boys run these batteries. If you take care of them you'll get a long life and great performance out of them.

Or, since it doesn't sound like you've actually gotten stranded or have any real complaints on how your batteries have preformed in that past, there's always the "leave what's working alone" approach and just replace what you have with new versions of the same. Sometimes the easy thing is the best way to go.