3 batteries to 2

[family affair]

I'm likely going to be replacing a battery or 3 this off season. The boat is set up with the standard GW 3 battery system for twins and 2 switches. I'm considering going to a dual purpose LiFePo chemistry from Ionic. If I do this I'm also considering going from 3 batteries to 2. The 2x 100 ah batteries will have far more usable power than I would ever need and still far surpase the usable power of 3 group 27s.
Has anyone done this? If so, care to show how you wired the system? Are there any cons?

 

[wspitler]

Make sure you do your research, most of the LIFePO4 batteries are not able to be used as starting batteries. There are a few that are capable of starting but they are quite expensive. Installing the appropriate charger downstream from your alternators is also a bit pricey and the finished package is going to be more complex, a lot lighter, and more expensive initially for sure! On my 330 I have gone with four group 31, 2 deep cycle and 2 starting, each type serving a single battery position. and I’ve been quite happy with their longevity.

 

[family affair]

Ionic has starter, dual purpose, and deep cycle with rave reviews and a lot of users.
I'm now wondering if I might be better off sticking with the 3 battery set up. Go with 2 smaller 40 ah starting batteries and one 100 ah DP.?

 

[wspitler]

Ionic has starter, dual purpose, and deep cycle with rave reviews and a lot of users.
I'm now wondering if I might be better off sticking with the 3 battery set up. Go with 2 smaller 40 ah starting batteries and one 100 ah DP.?

I’ve noticed the improvement in types. not being a early adopter of technology, I’m a little afraid to set my boat up that way yet. Another couple years I think it might be a great idea! The prices continue to come down as well. I’d be very interested in what you decide and how it all comes out!

 

[family affair]

The thought of not having to guess how much power you have available and the ease of troubleshooting is so appealing. The life is exceptional also. Not having to lift a 50+ lb battery into the insanely inconvenient bilge is another great advantage.

 

[Hookup1]

Seems like a lot of work to me. I just recommended the Duracell Marine AGM's to another member.

My thruster battery went this Spring. 5 years old. Did all 4.

I'm using Duracell Marine AGM batteries from Sam's Club. I use the 34's for starting batteries (Yamaha 150's), 34 for the bow thruster and the 27 for the house battery. Great price and have not had any problems. Also made by Eastern Penn. Make sure your charger supports AGM. I'm using ProMariner ProSportHD 20.

Search for duracell marine agm - Sam's Club

www.samsclub.com

Group 34 43.10 lbs. 955 MCA 55 AH. $134.86
Group 24 52.40 lbs. 800 MCA 78 AH. Did not see availability at my store. Use 34 instead.
Group 27 61.55 lbs. 900 MCA 92 AH. $199.28
Group 31 67.35 lbs. 1,000 MCA 105 AH. $214.32

 

[family affair]

Thanks for the perspective Hookup. However, at that price point I'm more than half way to 2x 30 ah starting batteries and a 100 ah house.
I need to check with Ionic to make sure the 30 ah batteries will work for marine starting. The numbers indicate they will. If not, I'd have to go to 40 ah batteries and then we are talking 3x the cost of acid.

 

[dogdoc]

Seems like 2 questions here. First adopting new battery technology. Do not have a dog in that fight so no comment, except good luck hope it works for you. Second going without a dedicated house bank, something I would never, ever do.

 

[Beyond A Wake]

I have no idea about the conversion requirements so I'm really just asking questions to be able to assess the possibility to switch when I need to replace the current set of 4 batteries.
1. Do the motors alternators satisfy the charging requirements?
2. Do the standard pro mariner 50A support the Li battery charging?
3. Starting or house I don't see it makes that big a difference as the starting draw is so short that a house deep cycle battery should easily handle it, not so much the other way around though.
4.The cost difference is huge? so the lifespan of "normal" AGM batteries being 4? Years would have to be multiplied by X to make it feasible, any answers to what X would be?

H

 

[family affair]

I have no idea about the conversion requirements so I'm really just asking questions to be able to assess the possibility to switch when I need to replace the current set of 4 batteries.
1. Do the motors alternators satisfy the charging requirements?
2. Do the standard pro mariner 50A support the Li battery charging?
3. Starting or house I don't see it makes that big a difference as the starting draw is so short that a house deep cycle battery should easily handle it, not so much the other way around though.
4.The cost difference is huge? so the lifespan of "normal" AGM batteries being 4? Years would have to be multiplied by X to make it feasible, any answers to what X would be?

H

1 - yes
2 - I don't know, but I'm guessing no.
3 - Is it a battery issue, a starter issue, or both?
4 - Most have an 11 year warranty. I'm confident you would get your $$ back with several other significant perks.

 

[family affair]

After going through the wiring system, it appears GW combines the starboard start and house systems. They are not isolated in any way. The only thing that is isolated is the port engine and battery. I'm heavily leaning towards a single 100 ah DP for the house and starting needs and then go with a 30 ah starting for the port. That gives me about as much usable ah than 3 group 24s.

 

[SkunkBoat]

Having different size batteries effects charging and battery life if you don't keep them isolated

Unless you have a thruster and/or an electric trolling motor, I question the advantage of using lithium batteries.
Electric motors will require a lot of capacity and you would need to save weight vs Lead if you are using 5 or 6 group 31 deep cycles.
Lithium requires a different charging scheme and you may need additional equipment to charge them from your motors.( a DC to DC charger)

For the majority of boaters, flooded lead acid bateries are very capable of 5 years of use for about $100 each (or less).

You have twin 225 OX66s? Two Battery switches?
You currently have grp27s or do you currently have 24s?

If you have 3 group27s now, then you have space for them. I would stick with that.
If you have 24s you probably don't have room for 27s

Do you have Aux Charging cables that charge all batteries regardless of switch positions?
I highly recommend this. Otherwise, use ACRs to do the same function.

I ran twin 225 OX66s on grp24DP flooded cell lead batteries setup like yours. A 24DP is plenty of battery to start an OX66 if it is kept charged.
A parallel pair of 24DPs will run Nav/Anchor lights, 2 LED floods, an UW LED, an MFD and a Sonar from dusk to dawn without ever running a motor.

I eventually reconfigured to split the House from the start batteries. see https://www.greatgrady.com/threads/new-battery-config-for-265.25744/

 

[family affair]

Having different size batteries effects charging and battery life if you don't keep them isolated
That's why the latest plan is a 100 ah for starboard and 40 ah for port to keep them isolated. FWIW, IONIC tech support states it doesn't matter if a 40 is in parallel with a 100.
Unless you have a thruster and/or an electric trolling motor, I question the advantage of using lithium batteries. I would have at least 3x the life, 70% less weight, the same amount of usable power, complete transparency of remaining power, 11 year warranty, emergency reserve starting capacity, and probably another thing or 2 I forgot. I could buy 3 new dp group 24s for $500 (I'm due) or 2 lithium for $1200 with a charger.

Electric motors will require a lot of capacity and you would need to save weight vs Lead if you are using 5 or 6 group 31 deep cycles.
Lithium requires a different charging scheme and you may need additional equipment to charge them from your motors.( a DC to DC charger) Ionics are time tested drop in replacements. The BMS has been extensively tested for outboard alternators.

For the majority of boaters, flooded lead acid bateries are very capable of 5 years of use for about $100 each (or less). The best price I can find is $150 each locally.

You have twin 225 OX66s? Two Battery switches?
You currently have grp27s or do you currently have 24s? I have twin df200 aps, 2 switches, 2 group 27 and one 24 on the port engine.

If you have 3 group27s now, then you have space for them. I would stick with that.
If you have 24s you probably don't have room for 27s

Do you have Aux Charging cables that charge all batteries regardless of switch positions? No.
I highly recommend this. Otherwise, use ACRs to do the same function.

I ran twin 225 OX66s on grp24DP flooded cell lead batteries setup like yours. A 24DP is plenty of battery to start an OX66 if it is kept charged.
A parallel pair of 24DPs will run Nav/Anchor lights, 2 LED floods, an UW LED, an MFD and a Sonar from dusk to dawn without ever running a motor.

I eventually reconfigured to split the House from the start batteries. see https://www.greatgrady.com/threads/new-battery-config-for-265.25744/

View attachment 31504

 

[SkunkBoat]

Sounds like IONIC will work for you. You 've done your research.
I am assuming you know if the 40ah has enough cranking amps.

So you run on stbd switch position 1 and port position 2
the STbd motor charges the larger Stb battery and port motor charges port battery

Unless you troll on one motor often, you don't need the Aux cables or ACR.

The house runs off stb battery and stb motor

You use the switches to turn off batteries and House when you leave the boat.
The switches can be used in an emergency to swap batteries.

I don't see any problem with it. let us all know how it works out.

 

[family affair]

Believe it or not Ionic has a 30 ah that has 900 cca and it weighs less than 15 lbs! The 40 ah is a beefier design for marine applications - or so they claim.
My only pause at this point for the lithium is a malfunction. If they take a crap, will they fry my electronics? You can only fail safe a design so much. Of course Ionic will tell you they thought of everything, but who knows. All I can go by are all the satisfied guinea pigs/customers. So far I have not read of one single issue of significance other than dead batteries.

 

[SkunkBoat]

Believe it or not Ionic has a 30 ah that has 900 cca and it weighs less than 15 lbs! The 40 ah is a beefier design for marine applications - or so they claim.
My only pause at this point for the lithium is a malfunction. If they take a crap, will they fry my electronics? You can only fail safe a design so much. Of course Ionic will tell you they thought of everything, but who knows. All I can go by are all the satisfied guinea pigs/customers. So far I have not read of one single issue of significance other than dead batteries.

the bass boat guys have been using Lithium for a while. They pack thier boats with batteries for their electric motor(s). They need to save the weight.
The weight isn't much of an issue on a 26ft Express as on a 16 ft bass boat.

I don't want to sound like the old dude who doesn't like change. I'm sure the new batteries will eventually replace lead. And thats good.
Just like the death of 2 strokes. Never liked them anyways...

My biggest concern would be "do they actually last 11 years?" They tell me LEDs last 50000 hrs but I replaced my front porch LED bulb 3 times in 2 years.
Do I have to pay close attention to charging? Will just running the boat every week in season and on a charger in the winter, keep them good for 11 years?
My boat is in a slip and I haven't used the shore power charger all season.


Last year I got two 24M and two 24DC at Walmart (i had to go to 2 walmarts)for about $90 a piece. They were on the shelf. brand new a month old
That was just too easy to consider anything else.

 

[family affair]

I hear you loud and clear. There are risks, but how much? I can read about guys with Mercs or Yamahas running lithium all day. I haven't really seen any issues. Not much out there for Suzukis other than a few bass boat guys with 250ss engines.
I'll run a couple more questions by Ionic and make a decision.

 

[family affair]

Skunk, I've managed to thoroughly stir the pot over at THT on this topic. The one question that we can't get an answer to is how the Suzuki charging system handles a current load exceeding the alternator's output. What has been your experience with your group 24 DC batteries when they are run down? Conceivably those batteries could draw more current than your alternator can provide. I can't find anyone at Ionic or Suzuki that can answer this.

 

[SkunkBoat]

I have 4 batteries. I separated the House from the Start batterries. The House is two 24DC in parallel. The House bank is charged buy both Suzuki Aux charging cables. So it is always charging if either motor is running.
The most run down they ever get is after a full night of fishing. Ive never had an issue.

Each motor has a start 24M start battery charged by its motor

 

[Sardinia306Canyon]

@family affair​

Did you installed the LiFePo's or did any other change on your setup?

My new to me Canyon has 3 new 95Ah AGM Batteries but the other day listening to music, study the radar and programming the twin 8412xsv it seems i drained the starboard battery a bit.
Honestly i am not very comfortable with the GW way to connect the batteries and every time i crank the starboard motor the Autopilot beeps and show a low power warning. And that is usually poison for any electronics!
So i was study a bit about LiFePo's in boats (i knew already about LiFePo's in RV vehicles) and found out some interesting things regarding either a hybrid lead-acid and LiFePo or only LiFePo setup in boats.
As far i understood there are two problems with LiFePo's
1° The high ampere charging rate of LiFePO's can fry due overloading alternators
2° the BMS may shut of the LiFePo Battery if connected in parallel to jump start the other engine

The solution was to use a DC-DC charger who limit charge to 30A, Victron for example has one
To use a LiFePo Battery for Starter use as their BMS will not shut them off with less than 200A

I searched for a while more and found here in Europe a few LiFePO starter batteries who had both of the above included,
the can deliver cranking amps of 200 or 300A and have a built in charge limiter to keep charging current on a alternator safe level.
This means that they can used safely with any other device, basically a drop-in replacement.
Unfortunately i found them in boat shops and they cost around 1000$ for 100Ah what is about double or triple of a cheaper LiFePo. For replacing all 3 batteries it may be substantial cheaper to buy 3 Victron DC-DC chargers and 3 cheaper LiFePo's who can deliver 200A cranking power.

Chris