Battery upgrade 2022 m240

[RCorsa]

My prior boats my now retired mechanic used to always replace with high end batteries.  I’d live to know if anyone else does this to avoid low voltage gremlins that are seemingly so common now.  Not too worried about cost if the quality is worth it.   I know lots of car manufacturers are upgrading high end models with lithium batteries 

[shawndoggy]

Do you have an onboard charger?

[RCorsa]

Yes but I don’t want to plug it in every time I dock if possible.  

[RCorsa]

So really no one here upgrades the batteries?  

[MLA]

On 7/20/2022 at 9:04 AM, RCorsa said:

Yes but I don’t want to plug it in every time I dock if possible.  

The need to do this, can actually grow with the increased battery amp/hr. A larger battery will be harder for the alternator to replenish it. 

What was his definition of high-end batteries? Under what conditions, are the low voltage warnings? 

[mxmark4]

Lithium battery  weighs less hence you are destroying your wave by removing ballast. Not worth it. Just plug in your charger. 

[RCorsa]

From what I can tell,  2 Lithium batteries would be about a net 100lbs of reduced weight.  Given the m240 is 7500 dry with tower, gas and gears I assume it’s closer to 8500 plus the over 4 k in ballast I don’t think it would have any significant effect on the surf wave 

[RCorsa]

That’s what I’m looking for help with @MLA since I didn’t pay attention but my m235 had issues form day one with low batteries. I know they were about $300:each 

 

the issue now I’m seeing starting values around 12v and if I use the thruster it drops closer to 10.  After an hour of boating it will get to around 13.5 but I know lots of these electric gremlins can be a result of low batteries so I’m thinking of “upgrading” to see if these issues stop 

[CaptainMorgan]

Not sure the capacity difference with  the Lithiums you have in mind, but you need both total capacity and pretty high constant current draw. maybe you really just want a 3rd battery instead (I think I've seen other TMC thruster threads where this has been done).  

[MLA]

10 hours ago, RCorsa said:

the issue now I’m seeing starting values around 12v and if I use the thruster it drops closer to 10.  After an hour of boating it will get to around 13.5

This tells me, that the battery or batteries, are starting the day in a hole and not fully charged. This can be one of two things. The boat is put away with low battery(s) or there is a parasitic draw on one or the both. 

Using the onboard charger will solve the low battery when coming off the water, but would be a bandaid for a parasitic draw. Taking a voltage reading on both batteries after parking the boat for the night/week and then again prior to launching, but without using the charger for that period, would reveal a lot. 

[atLakeSantee]

If you remove electrons from batteries when starting, coving, and thrusting, then the electrons must be replaced regardless of battery technology.

To minimize the need for charging when docked, both batteries must be charging when the engine is running. If your boat only has a Perko-style battery switch with no automatic dual charging, then upgrading to automatic intelligent charging/combiner switch is better than moving from good to great batteries.

Something like the “Victron Energy Cyrix-i 24/48-Volt 400 amp Intelligent Battery Combiner“ will combine both into the charging process when charging occurs on either battery. It keeps them separated during normal times. 

[Dirtysidedown]

4 hours ago, CaptainMorgan said:

Not sure the capacity difference with  the Lithiums you have in mind, but you need both total capacity and pretty high constant current draw. maybe you really just want a 3rd battery instead (I think I've seen other TMC thruster threads where this has been done).  

Bingo!

I added a battery (3 total now on board) and upgraded to AGM’s.  I went with 2- Group 31 AGM’s in parallel for running everything, and a Group 24 wet cell for starting. No more low voltage alarms with thruster usage and high daily usage, I also plug into a charger after each use. I have plug right there on my dock, so it’s a no brainer.  
 

I have a thread with pictures, was able to fit everything in the factory location.

Fixed the problem and added extra ballast up front as an extra bonus!

Edited July 22, 2022 by Dirtysidedown

[RCorsa]

This is great advise and thanks for that.  I did search for battery upgrade and nothing popped up ( I always try this before posting on forums as I know it can be annoying to some). 

 

Anyway I have the same switch as you @Dirtysidedown.  Did you have to upgrade the charging unit when you added the 2 31s in parallel. any chance you have the dimensions of your overall set up.  I think this is a a good option to do especially since you noted its working great.  I assume the battery set up on the 2021 24MXZ and the 2022 M240 set up are the same from the factory? You did 2 31s and a 24 correct?  Your post above says a 34 but Im guessing that a typo?

 

Thanks again for this great suggestion.

[Dirtysidedown]

Yes it was typo, 1 Group 24, 2 Group 31’s. Have battery option 3 for the switch/ACR. No change to charging unit, I’m assuming you mean the on board charger, not alternator. But either way no change to anything.   The 2 Group 31s in parallel are essentially 1 giant battery. I have one bank of the charger to the starting battery, and one bank to one of the Group 31’s, but both get charged since they are connected in parallel

[RCorsa]

So I pulled out the bow and this is my set up with three batteries already!  
 

thoughts?

[Dirtysidedown]

That is very nice, and exactly the same(in theory)as what I had to cram into my tiny spot.  Perhaps you could get slightly “bigger” battery capacities by changing to different groups or manufacturers, but you have all the right stuff there.  The top battery looks like the starting battery, and the 2 back ones side by side are the house batteries that run everything else. Those would be the only ones I would look into making an adjustment to if you felt you wanted something upgraded, but from what I see those are pretty strong.

For example, my Interstate AGM 31’s have a 200 AH reserve capacity each and where $375,Batteries Plus has their X2 AGMs that have 220 AH reserve but they cost $450/each.  You have 175 AH RESERVE, so you would only be gaining 50-90 AH of reserve capacity for the set for $700-900.  Perhaps that’s where the lithium’s come into play and you could get that the AH RSV capacity to jump way up. But I’ve never looked into what those numbers may be

It’s been discussed, but I think the 170 amp High output alternator is the problem and it would really help if was even bigger.

I would plug in the boat religiously as my first step from where you currently stand. Then find 2 of the highest AH reserve capacity batteries you can get to fit as step 2. The good news is all your wiring is set up and it will be a very simple process

Edited July 22, 2022 by Dirtysidedown

[MLA]

I feel you really need to figure out what all is happening electrically, when the low bat warning occurs. Is it after hours at the part cove then a 5 minute ride back to the dock? Does it take 10 minutes of thruster use to get the boat docked? A thruster can consumer considerable amount of juice when in use, but its usually short burst and the over all thruster use should be long. A good charging system should be able to recover that in a short amount of time. A 170A alternator should not have any issue supplying the system, unless two large Ah house batteries are being pulled deep at the party cove.   

[Stevo]

Did we already recommend checking the +&- connections at the engine block?

@csleaver posted  about this in another thread , and I’ve passed that info to 2 friends that found loose grounds at the engine block

-2018 23lsV

2020 25lsv

[RCorsa]

Yes. I e checked all the connections at the battery and the engine block.  My guess is the the battery charger was not being used regularly and I know things like the auto bilge and the gx tower have some parasitic drain on the system even with the battery switch off.  
 

I’ll try leaving the system on the charger for a few days but my thinking is when the battery is switched on the system should show between 13-14v rather than 12v?  As mentioned, the system starts low and I always need a few hits of the thruster to get out of my dock and even just a few pushes brings the system down to around 10v so something is off here.  

[CaptainMorgan]

Suggestion: take a voltmeter to each of the 3 batteries individually (separately). Like 12.8V is fully charged, while low 12's can be like 30% ( google for tables of approx V vs % charged). I'm curious if all 3 are being drained or if 1 bad battery is pulling the other 2 down.

My understanding is the auto bilge is only connected to 1 and I assume same with tower...i fear there is another parasitic draw somewhere as I just cant fathom that overnight leakage from those are enough to be noticeable on a 3 battery setup like you have....or...

Only other thought is that if you use thrusters a decent amount docking and immediately shut off engine, size of alternator is irrelevant as theres no time to charge and thus batteries are by definition not topped off the next day.

[Dirtysidedown]

Just to piggyback and clarify, with the boat off, having just unplugging the charger that says 100%, and switching the batteries on, I’m normally at 12.6-12.8 if memory serves correctly.  As soon as I fire it up and the alternator gets going it’s steady at 13.7-13.8

Leaving my slip, I am immediately getting on the thruster to do a 180* degree maneuver with various amounts of constant blips and  steady usage for probably 45-60 seconds.  The volts definitely drop to the 11’s, but immediately climb back to 13.7-13.8 and cycle up and down with usage as soon as I let go of the button. I have not gotten the low house volt warning again after I upgraded my system, essentially to what you have and use the charger.

I had 2 Group 34 starting batteries to start with which is not your case obviously.  
 

 

Edited July 22, 2022 by Dirtysidedown

[smileysteve]

I've done the "inverse" of upgrading the battery. When I added a reversible ballast pump, I added a 16f ultacapacitor to help out the pump. I also trickle charge now whenever it's not used every other week (especially winter), which desulfates it. 

My flooded lead acid is now 8 years old. I think I'll finally replacea next season, which I plan to upgrade to a AutoZone AGM marine 24.

I don't have a thruster, only a 1k watt amp, the 2 vane pumps at a time and a reversible. 

[RCorsa]

So I used a voltmeter as each battery was at between 11.2-11.4 after sitting on the built in trickle charger overnight. I read how these deka batteries can start failing in under a year.  My boat was delivered from the factory in September of last year.  However, I waited on actually picking up the boat from the dealer until  March of this year since our season ends in September/October anyway.  I wonder if all that sitting damaged them so now they won’t hold a charge?  I assume the dealer had them on a charger but I assume its possible they did not 

Edited July 22, 2022 by RCorsa

[CaptainMorgan]

38 minutes ago, RCorsa said:

So I used a voltmeter as each battery was at between 11.2-11.4 after sitting on the built in trickle charger overnight. I read how these deka batteries can start failing in under a year.  My boat was delivered from the factory in September of last year.  However, I waited on actually picking up the boat from the dealer until  March of this year since our season ends in September/October anyway.  I wonder if all that sitting damaged them so now they won’t hold a charge?  I assume the dealer had them on a charger but I assume its possible they did not 

Sub 12V after being on a charger? Something is amiss. Either batteries are bad or your boat is killing them for some reason. Maybe try charging them overnight on a 10A charger in your house and see what they say?

 

Edited July 22, 2022 by CaptainMorgan

[atLakeSantee]

30 minutes ago, RCorsa said:

So I used a voltmeter as each battery was at between 11.2-11.4 after sitting on the built in trickle charger overnight. I read how these deka batteries can start failing in under a year.  My boat was delivered from the factory in September of last year.  However, I waited on actually picking up the boat from the dealer until  March of this year since our season ends in September/October anyway.  I wonder if all that sitting damaged them so now they won’t hold a charge?  I assume the dealer had them on a charger but I assume its possible they did not 

Do you truly mean all 3 batteries at between 11.2-11.4?  If so, the boat has multiple issues.  The start/run battery should not be attached with the other two, so it has something drawing it down separately.  The pair of deep cycles wired together should be expected to need replaced every 1-2 years because the two will degrade each other when not being charged.

What current rating is the trickle charger?  If is a small 1-5 amp charger/maintainer, then an upgraded charger is needed for the nightly recharge.

Also, the auto bilge does not draw current overnight unless its pumping water out the side.