Battery type

I have a 2018 Supra SL I put the two 27D that comes with boat in parallel and on bank 1. Added another large 4D battery on bank 2. This is how I have done it with my Seadoo 18ft utopia and also my 2007 malibu 23 lsv. This is what’s needed for a stereo this powerful so you can listen for a long time and not drain battery.

I don’t think I left any electronics on and my bank 1 was dead. So started boat with bank 2.i think only the auto bilge is hard wired to battery. And I had no water in boat so don’t know what caused bank 1 to be dead unless I made a mistake and left battery switch on or if the alternator is broken,

When I started boat with bank 2, voltage level is 14 volts which should imply the alternator works. However after running boat I switched to bank 1 and ran above 3500 rpms for an hour and shut off boat and bank 1 was only at like 10 volts . So maybe it takes longer than an hour to charge a dead battery and I understand an alternator shouldn’t be used to charge a dead battery or could damage alternator.

I called Supra mechanic and was super disappointed . First off , all these boats have a popping noise thru audio when starting boat. Huge flaw and I know it’s caused by the huge voltage drop when starting these engines and they put in too small batteries . Mechanic called Supra and they said it was designed this way. So a $160k Boat was designed to give a huge pop to stereo ? What an idiotic response.

Then mechanic says Supra says only 27D can Be used and non AGM. I asked why and he says cause this boat is very sensitive to voltages. Another idiotic response. So we spend $160k on boats and this is the technical service we get ? They should explain the technical reason.

Since when does a boat not support AGM batteries ?

And as long as you are not using alternator to charge dead battery , there’s no reason you should not be able to use a battery larger than 27D. And if so then what’s the technical explanation ?

And the 4D resolves the audio popping issue which will eventually blow the speakers

Any one out there that had the knowledge to comment ?


Joe mama

I'm not sure if it's in the Supra manual but it seems related to why you aren't supposed to run the boat in 1+2. Differences in battery banks could cause a voltage issue that can damage sensitive electronics.

"Skier’s Choice installs a 4-position battery switch on any boat equipped with dual batteries. It is recommended that both batteries
be fully charged between each use to insure they can deliver the electrical demands required for each outing. The purpose of our
recommendation is to utilize one primary battery for all operational needs, and have the other as a backup if the primary battery
discharges. This situation could occur if you run your accessories such as ballast or stereo for a long time, without running the
boat. The dual battery setup is designed to create a redundant system allowing the user to have a backup battery. The switch
must be in the “1” or “2” position to create the redundancy.
The 4 positions available on the battery switch are: Off / 1 / 2 / 1&2. These choices indicate which battery is being used to power
the boat and which battery is being charged by the engine’s alternator. We recommend using only position 1 or 2 while boating.
Battery switch position “1&2” is available but not recommended as power will be drawn from both batteries and the alternator
will have difficulties keeping both batteries charged simultaneously. It also creates a ground differentiation which in turn will
create issues with sensitive electrical components such as
the Vision screen. The only time you may need Position 1 &
2 would be in an emergency situation where both batteries
are low and need power from both to help start the engine."



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Yeah the amp pop at start up is FN annoying.


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I was told by skiers choice to run the boat in 1+2 to avoid the stereo pop. Well the other night that left us stranded. I wish skiers choice would address this issue. I think they hope the problem will magically heal itself. Has anyone had any luck with a different battery set up?

I guess it was not explained to switch to 1 or 2 when anchored?

I have never had stereo pop upon start up, that goes with starting with battery one, two or one and two together. Also my dealer installed an AGM battery in my boat, it's what was in it when I took delivery. Strange they told you not to use one. I love AGM, adding water is a PITA.

I also run my boat in 1+2 all the time unless im anchored for an extended period with the stereo on, then I used just 2 (2 GC batteries wired in series). Guess I need to stop that.

RD, I think the popping is more of a Supra thing with the ICE system than what happens on startup with the Moomba's. Our Mojo never popped, but there is a slight pop on the SA, but not bad enough for me to worry about right now. I was also told to run in either 1 or 2 after crank up, not both, as running both may stress the charging system. Not sure how true that is, but not had any issues running it like that yet.

I have always run in 1+2 when starting up and when surfing, wakeboarding, etc. When I get to party cove I switch to battery 1 or 2.

I do have the loud pop on start up and cannot get rid of it starting with battery 1, battery 2 or battery 1+2.

I would think that after the "thermal event/bad alternator scare" that they just had that we would get a definitive answers to questions concerning this and a resolution to the popping on startup from Goose or one of the Tinkers.

MLA, you have any thoughts on the Supra voltage drop pop and running all the time in 1+2 stressing the charging system or not? Could a larger ground be ran or even a cap added to maintain a certain level on crank up? I know mine isn't bad, but I have been on a few that sounds like everything is bottoming out its so loud. Can't be good long term for the system

I got thoughts and I laugh at the premise that the electrical system is to blame. The power system can't be changed. The equipment connected to the power system needs to be adaptable. Component line filtration is required for sensitive electronic equipment. Look into a L or Pi filter. They are normally built into systems but not every manufacturer does this.

Isolating the electronics from the starter at startup should never cause noise unless the cables are so close to induce noise. Running banks 1 and 2 should occur when the engine is running.

Found this, explains it very well.


https://www.boattest.com/view-news/3...switch-dilemma

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Originally Posted by KnoxMojo

Found this, explains it very well.


https://www.boattest.com/view-news/3...switch-dilemma

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Except for the dead battery scenario and switching to both.

If one battery is dead and the other full they will equalize and result in 2 weakly charged batteries and probably not enough to start the boat.

Best to start the boat with the good charged battery then switch to both so the alternator can charge them both.

The other option is you forget to switch to the other battery to keep it charged. Then you drain the other, now you have two dead batteries.

Best to leave it always on both., unless sitting in the cove, then switch to one battery so you don't kill both batteries. Then after starting go back to both so both batteries are charging.

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Originally Posted by parrothd

Best to start the boat with the good charged battery then switch to both so the alternator can charge them both.

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It said in the article that it would not charge both equally in that scenario.

"If the switch is in the “BOTH” position and one battery is nearly at a full charge and one is flat, the alternator will “read” the higher of the two, and the flat battery will never be charged"

I think the better way would be to start the boat with just the good battery as you said, then switch to the other battery while cruising. The alternator will both run the boat and charge the weak battery.

It also says this.. "NEVER use the “BOTH” position except to parallel both batteries if they’re both flat, almost like an attempt to “jump start” your own engine.

But to each their own. I have been more doing it this way for years and have never been stranded.

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Originally Posted by KnoxMojo

I have been more doing it this way for years and have never been stranded.

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Knock on some wood Knox...quickly!!

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Originally Posted by Prospersigman

Knock on some wood Knox...quickly!!

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How so? I always have at least 1 fully charged battery. Unless my alternator goes out, how would I get stranded? And I just knocked on wood (my head) for good measure..lol

Quote:

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Originally Posted by KnoxMojo

It said in the article that it would not charge both equally in that scenario.

"If the switch is in the “BOTH” position and one battery is nearly at a full charge and one is flat, the alternator will “read” the higher of the two, and the flat battery will never be charged"

I think the better way would be to start the boat with just the good battery as you said, then switch to the other battery while cruising. The alternator will both run the boat and charge the weak battery.

It also says this.. "NEVER use the “BOTH” position except to parallel both batteries if they’re both flat, almost like an attempt to “jump start” your own engine.

But to each their own. I have been more doing it this way for years and have never been stranded.

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The author doesn't seem to know how alternators and batteries work. I would carry jumper cables.. lol..

If you have a battery that can't maintain a charge, toss it. A dead battery is considered a load and
a big on at that. Both batteries connected while running will have the same voltage but the current draw will be different. Having a huge alternator, the batteries will be charging around 14 volts. So run 1+2 while running, isolate the batteries when shut down.

Sure thing, just in case you need them...lol

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Originally Posted by KnoxMojo

How so? I always have at least 1 fully charged battery. Unless my alternator goes out, how would I get stranded? And I just knocked on wood (my head) for good measure..lol

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Just didn't want you to jinx yourself thats all...

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Originally Posted by zabooda

If you have a battery that can't maintain a charge, toss it.

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Completely agree. chuck it.

Wonder if these new boats come with an ACR, or automatic charging relay? In that case, would it really matter if it was just left in both at all times? Or any sort of charge management for that matter. Guessing that article from boat test was talking about just a standard switch with nothing else. But I do tend to crank in both then switch to 1 or 2 and never had an issue. and only one or the other anchored out or tied up.

Quote:

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Originally Posted by Prospersigman

Just didn't want you to jinx yourself thats all...

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Thank you sir, I hate seeing people that need to be towed over something simple.

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Originally Posted by KnoxMojo

Sure thing, just in case you need them...lol

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I use them all the time, at least twice a year. Always some dude with a loud stereo, they go to start and click, click, click. Lol.

The Supra manual says use 1 or 2 and only both if you need a last chance to start, also never turn to off while the boat is running.

The one interesting thing the manual says is use “dual purpose” batteries.

My dealer installed marine deep cycle batteries.


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Quote:

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Originally Posted by KnoxMojo

MLA, you have any thoughts on the Supra voltage drop pop and running all the time in 1+2 stressing the charging system or not? Could a larger ground be ran or even a cap added to maintain a certain level on crank up? I know mine isn't bad, but I have been on a few that sounds like everything is bottoming out its so loud. Can't be good long term for the system

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Is it correct in that the pop only happens when the stereo is on and you crank the boat? No pop if you turn on the stereo with engine off, or wait to turn it on after the engine is running? The recommendation to run on 1+2 seems like they are chasing a voltage sag.

First have to determine which circuit is falling out of sequence. Is it the IGN turn-on? (may not even be one). Is it the constant B+? Or is it the amps hitting their voltage threshold and cycling off then back on.

Both the ground and B+ share the load equally, so if one needs to be upped, both would, unless one is smaller then the other, which would be odd.

Load, or stress on the charging system is relative to the discharged level. So two batteries can be now more load to the alternator then one battery. Think of audio amplifiers. five 100W amps are in theory, no more of a load then a single 500W amp. Same with batteries.

A large stiffening CAP may "fix" the issue, but they can be a liability to the battery(s) on toys that are not used regularly.

Only pops when you start boat with radio on.

I am surprised Supra hasn’t fixed this yet

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Wonder if these new boats come with an ACR, or automatic charging relay?

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Does not sound like it, hence the 1/2/BOTH switch, the pop and the recommendation to run with the switch on 1+2.

With the DCP switch and ACR, the house loads are isolated from the engine loads, so there would never be a voltage drop on the house side, created by the engine side.

Supra does not recommend running in 1+2 mode.


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Quote:

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Originally Posted by larry_arizona

Supra does not recommend running in 1+2 mode.


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Not sure why having the switch and having HD alternator if they don't want to simultaneously charge all of the battery banks. I can see issues if one didn't know how or when to operate the switch. They should automate it then as the motor home industry has been doing for years.

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Originally Posted by zabooda

Not sure why having the switch and having HD alternator if they don't want to simultaneously charge all of the battery banks. I can see issues if one didn't know how or when to operate the switch. They should automate it then as the motor home industry has been doing for years.

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You can install marine isolator, they're cheap, it automatically charges both batteries, but keeps the batteries separate.

One battery for your stereo and another battery for starting. You don't need to mess with the switch, it does it automatically.

Not the prettiest setup but I added an acr this winter to my 16 mojo, works great. Worth the time installing. https://uploads.tapatalk-cdn.com/201...15ed5aebda.jpg

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Schwan, that is awesome!! New goal for a rainy day. How difficult was it to do?

MLA, I played with it yesterday, and keep in mind, this pertains to the Supra system. Without my Bluetooth connected and stereo on, no music playing, no pop on crank up. Bluetooth on and music going, pops on start up. Shut boat down, turn on music and then key on, no pop and music plays. Did not matter if boat was in 1 or 2 or both. One thing I didn't try was to pause the music and then crank it up, knew I forgot something.

This has been a very informative thread for me and hopefully others.

Good info, knox. IIRC, on the Surpra, the BT is an external component, so that also factors in as its another piece in the signal path, AND it likely has its own power supply. It also has its own shut down and boot up timing.

Anyone getting the pop in other modes besides BT?

We had an Iphone connected via usb the other day to charge and the music was playing through it in aux, and it did pop on crank up.

MLA, if you give me some direction, I am pretty handy with a DMM from my Radar repair days. If I need an oscope or spec-an, well, those are skills that have long since left me, lol

Knox, not hard if you have 12v knowledge and you know what wires go where. It's so worth it, you never have to worry about what battery you're switched to.

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My Supra is always on Bluetooth and pops on start up.

I will try with Bluetooth off.

Isn’t the Gussi steering wheel always using Bluetooth?


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Originally Posted by KnoxMojo

We had an Iphone connected via usb the other day to charge and the music was playing through it in aux, and it did pop on crank up.

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Ok, this steers the focus back to the ICE, rather then a peripheral like the BT.

You will likely need a meter with a MIN/MAX feature so you can capture a voltage drop that may not otherwise, make it to the meter's display, given the short time span thats needed to created the event.

4 main circuits need to be monitored:

ICE constant B+
ICE switched IGN
ICE amp turn-out
AMP voltage

Now, the ICE may not have both a constant and a switch IGN. Many new units now use EEPROM memory and have no need for a constant, so they just use a switch IGN. Ive got the ICE PDF tucked somewhere, just need to dig it up.