Battery Charger Amperage for 230?

[paticus]

My 2019 Nautique 230 did not come with an on board charger. The boat is in the shop (which is closed), and I am trying to figure out which charger to purchase. From what I can tell, Nautique uses the ProSport charger if you buy the charging package from the factory.

The dealer recommended the 8amp dual bank, however the nautique parts only show 10 and 12 amp options.

Just curious if anybody has a late model 230 could recommend a charger and/or amperage to fit those stock batteries. Unfortunately without the boat and dealer closed, I have no specs on the batteries.

[GMLIII]

My 2019 Nautique 230 did not come with an on board charger. The boat is in the shop (which is closed), and I am trying to figure out which charger to purchase. From what I can tell, Nautique uses the ProSport charger if you buy the charging package from the factory.

The dealer recommended the 8amp dual bank, however the nautique parts only show 10 and 12 amp options.

Just curious if anybody has a late model 230 could recommend a charger and/or amperage to fit those stock batteries. Unfortunately without the boat and dealer closed, I have no specs on the batteries.

I just installed the NOCO two bank 8 amp charger in my G23 and I have been pleased thus far. I placed the charger in the port stern locker so it was out of the way and my charging port is midship on the port side. Perfect set up for me.

https://no.co/genm2

[shag]

I also have the exact same NOCO charger as above. Have had it in my 230 for about 3 years without any problem. Does a great job maintaining your batteries. Additionally, I alternate batteries each outing.

[MLA]

20A dual bank at least

[shag]

Whatever you do, don't buy cheap when it comes to a charger/maintainer. Fire hazard is real with the cheap ones.

[ScooterMcgavin]

+1 for the NOCO dual bank, great products

[GMLIII]

I don't want to split hairs with MLA's opinions on battery related topics because no doubt he is the most knowledgeable in that regard on this forum. I did think about the 20A, as MLA recommended but under the NOCO reviews on that particular amperage on board charger, I read some horror stories that it was too strong thereby frying the batteries in the boat. For that reason along, I purchased the 8 amp NOCO onboard charger instead.

[paticus]

This was actually at the root of my question. I was wondering if a bigger (more amps) charger was better to get. Do these chargers have enough smarts to not fry smaller batteries?

MLA, can you expand on your recommendation for the 20A?

[GMLIII]

Hence why I went with the 8 amp

[shag]

I have quite bit extra hooked to my electrical system (multiple underwater lights, Amps, ect) and do a lot of sitting with the music up and lights on and needless to say, probably don't adequately get time recharging the batteries under operation from the alternator. This smaller dual bank NOCO handles the two larger group size batteries I have just fine and without problem. Batteries are always charge and ready to go.

[MLA]

To GMLIII. Just to clarify, I did not recommend a NOCO, or any brand for that matter. If a multi-stage smart charger is over charging a battery, its not a very smart charger. Even a 4A charger can over charger a battery. heck, those 1A trickle chargers will over charge. I tend take reviews, both good and bad, with a grain of salt. In the case of a 20A charger cooking the batteries? Lots of other things, including user error, that can lead to some undesired outcome, with all the blame going to one component.

With a multi-stage smart charger, its total amp capacity is mostly like horse power in a tow vehicle. Its there when you need, but should not result in a speeding ticket every time you hit the hiway. The charger should not supply any more to the batteries, then what the battery requires, to a degree. Much like the regulator in the alternator, its supply is based on demand, yet a smart charger is much smarter then a typical alternator.

A rule of thumb is to go with a chargers whose capacity is at least 10% of the battery(s) total Ah. Take for example, a pair of group 24, which likely have about 85 Ah each, for a total of 170 Ah. So following the rule, you'd be looking at a 17A 2-bank, right? Not sure if anyone makes a 17 Ah, but there sure are plenty of 20A, so its a good option for a pair of batteries.

In the case of the NOCO 20A 2-bank specifically. It will only deliver HALF of its rated capacity to each bank. So that = 10A p/bank. On a typical group-24, thats no where near excessive. The NOCO 8 2-bank is only going to deliver 4A p/bank. IMO, thats not enough to desulfate a deeply discharged house bank, not too mention it will take longer to replenish. A higher amperage capacity = higher bulk rate to get through the desulfation, and into the float mode sooner. Bottom line, a larger capacity charger does not work as hard as a smaller capacity charger would on the same battery setup.

One feature I DO like about the Promariner lines of chargers, is their distribute on demand. For example, a 20A dual-bank charger has the ability to supply up to its full capacity, i.e. 20A in this example, to which ever bank needs the most. Say you come off the water after being anchored in the party cove all day, and your house bank is dead. The Promariner will prioritize the house bank with the bulk of its capacity, then begin to supply some to the main cranking bank, which likely does not need any. So in a way, your 20A 2-bank can act like a 20A 1-bank for a short period.

And Shag is correct, the alternator will not do a good job or replenishing a dead battery, with a typical short ride back to the dock.This is why its important to use an on-board charger right after the boat is put away.

Hope this helps.

[core-rider]

MLA did a great job of explaining this, but to maybe add a bit...

If using a traditional lead-acid battery... during charging the battery will have some off-gassing and just natural evaporation causing the electrolyte level to drop and expose the lead plates which could cause the battery to overheat and fail prematurely. Keep an eye on your electrolyte levels as per regular maintenance and you should be fine.

This is not true of sealed battery types.

Also, when deciding on a charger for my system years ago I talked with ProMariner support about using a 2-bank or 3-bank charger since I have 3 batteries, but in a 2 bank setup (starting and house). In my mind the 2 house batteries are basically 1 big battery since they are wired in parallel meaning I only need a 2-bank charger. ProMariner tried to explain I needed a 3-bank though because the charger would still see 2 batteries on the house side instead of 1. I don't know if this is all true, but I went 20 amp 3-bank and have had flawless charging for 8 years now. Just something else to think about depending on your system configuration.

[MLA]

Also, when deciding on a charger for my system years ago I talked with ProMariner support about using a 2-bank or 3-bank charger since I have 3 batteries, but in a 2 bank setup (starting and house). In my mind the 2 house batteries are basically 1 big battery since they are wired in parallel meaning I only need a 2-bank charger. ProMariner tried to explain I needed a 3-bank though because the charger would still see 2 batteries on the house side instead of 1. I don't know if this is all true, but I went 20 amp 3-bank and have had flawless charging for 8 years now. Just something else to think about depending on your system configuration.

Here is my way of answering this scenario. Yes, two batteries wired together permanently, will act as one large battery. Although the charger will not "see" these two batteries with only a single output, it will see the load of the 2 batteries, which will be greater then 1 battery or 2 batteries each on its one bank.

In the above setup, I do like a 3 bank charger for this reason;. We can spread the charge load of the large house bank across 2 charger outputs, rather then one charger output supplying the large bank. Even though the two batteries are one large bank, The Promariner chargers, and some others, work perfectly fine with 2 output banks, charging a single bank.

Another scenario where this works, is with a large Ah house bank like a pair of 6V golf cart batteries. This can be 250 Ah, so stacking 2 banks of a 3-bank on the house back, gives us that higher output, but spread across 2 outputs.

[scottb7]

And like you said IF it going to fail - smart or otherwise - then it going to fail, so you may as well get the right size...I would guess that the decent ones are engineered that if they fail they don't blow stuff up...

[paticus]

Thanks for all the suggestions and education, I ended up going with this. Now I just need to figure out how to get my boat back from the service dealer with this Covid situation..