Battery Charger/Maintainer Recommendations

[Onyx Z]

I bought a 2010 Supra Sunsport 21V over the summer and am a bit confused as to what charger to get to maintain the batteries during the winter months. I'm not worried about freezing as it won't get that cold in the storage building.

Battery 1: Interstate Cranking Marine 24M-XHD, 800CCA, 1000MCA

Battery 2: Interstate Deep Cycle Marine/RV SRM-24, 550CCA, 690MCA, 140RC

I understand standard battery basics, but I'm new to boat maintenance and deep cycle batteries. I know that I want a charger that doubles as a maintainer that I can keep plugged in for weeks at a time when the boat is in storage.

What charger can both charge and maintain?
Do I need a different charger for the different batteries or can it be swapped over or possibly daisy chained?
Any recommendations on brands/models?

[Wylietunes]

You want to look for a dual bank marine on-board multi-stage smart charger. In the 20A range is best, 15A is OK, 12A gets alittle light IMO.

The Pro Mariner Pro Sport 20 gen-3 is a solid unit at a good price. The NOCO Genius Gen-2 20 is another.

[MJHKnox]

I think it's a a good upgrade to install an on-board charger. A smart charger. I just plug my boat in and let the system monitor it.
I purchased an Inteli-Power Marine Battery Charger. Made by Progressive Dynamics.
Pretty sure it's a 30A, but its been awhile since I looked at it.

I have 1 house battery and 2 stereo batteries. (AMG)

Mark

[roosm]

I would say.
Remove the batteries from the boat. Keep them in your garage or where ever and top them off with a charger every 2-3 months during winter.

The smart chargers are great, but from the independent studies I have read it is just as good or better to top them off every other month.
The smart chargers do put some wear and tear on the batteries by maintaining them. I use a CTEK smart charger to charge the batteries, but just don't leave it on.
I know this is a bit more pain or quite a bit more pain than just leaving the batteries in the boat and plugging in your on board charger. Which also probably works great.

Using this method my current batteries are still going strong after 8 years of use. And those have been abused by getting low on power due to broken alternator, broken level-switch for the bilge pump which drained my optima to 5 V (more than once).
Also this would of course mean that you would get one charger, like a 5A or 10A CTEK or whatever brand you like and charge ONE battery at a time.
Less cost, just as good (or maybe even better, but I put as much faith into those reports as the ones from the lobbyists from the charger manufacturers) a little more pain.

For me, I already have another 4 or 5 batteries that usually do not sit in the supra to maintain so just as easy to maintain them all at one place.

Mike

[Onyx Z]

I would say.
Remove the batteries from the boat. Keep them in your garage or where ever and top them off with a charger every 2-3 months during winter.

The smart chargers are great, but from the independent studies I have read it is just as good or better to top them off every other month.
The smart chargers do put some wear and tear on the batteries by maintaining them. I use a CTEK smart charger to charge the batteries, but just don't leave it on.
I know this is a bit more pain or quite a bit more pain than just leaving the batteries in the boat and plugging in your on board charger. Which also probably works great.

Using this method my current batteries are still going strong after 8 years of use. And those have been abused by getting low on power due to broken alternator, broken level-switch for the bilge pump which drained my optima to 5 V (more than once).
Also this would of course mean that you would get one charger, like a 5A or 10A CTEK or whatever brand you like and charge ONE battery at a time.
Less cost, just as good (or maybe even better, but I put as much faith into those reports as the ones from the lobbyists from the charger manufacturers) a little more pain.

For me, I already have another 4 or 5 batteries that usually do not sit in the supra to maintain so just as easy to maintain them all at one place.

Mike

I plan to use the boat during the winter months, just not every weekend like I would in the summertime. I do, however, want to have the option to leave it plugged in/charging for a few days/weeks/months/whatever without harm or worry of damaging the batteries, but also have them fully charged and ready whenever I choose to take the boat out.

I think I'm leaning toward an onboard smart charger charger, just not sure which one yet.

[Wylietunes]

The smart chargers do put some wear and tear on the batteries by maintaining them.

Im inclined to disagree. Battery reaches a full charged based on the battery type and the chargers algorithm and charger cycles off, or whats commonly called float mode. Charger senses a drop in static state of battery and kicks on. In theory, recharging the battery based on your time lapse and not the state of the battery, could lead to a deeper parasitic cycle, between charge periods than with the use of an on-board charger thats plugged in all the time. In other words, the charger may cycle on when the battery drops .5 a volt for example. Where as if the batteries are sitting in the garage for 2-3 months between charges, they could realistically see a drop of 1V in that time.

[Onyx Z]

I'm stuck between these two. I definitely want a 3-bank to have the ability to add another battery if I choose to do so. If someone wants to talk me into a 2-bank, I'm all ears.

ProMariner ProSport 20+ Gen3 20 Amp 3-Bank: https://www.amazon.com/ProMariner-Pr.../dp/B00F5EBTGA

NOCO Genius GenM3 30 Amp 3-Bank: https://www.amazon.com/gp/product/B0...DKIKX0DER&th=1


Really Stupid Question: A 30 amp, 3-bank charger runs 10A on each bank with all 3 banks on a battery. Running 2 batteries only uses 20A and the 3rd bank is automatically disabled? Or does it distribute the extra 10A to the other banks?

EDIT: Apparently the ProMariner needs 3 batteries connected to operate...

[Wylietunes]

You can always pull the fuses and tape off the leads for the 3rd bank until you need it, but im 100% the noco is not distribute on demand, so it only delivers the 10A per leg. However, you may be able to stack bank 2 and 3 on your bank 2 battery and gain the extra 10A. Some chargers this can be done but in not sure on the noco. That would be a question for them.

[wotan2525]

Even if you add another battery (3 total), your (2) stereo batteries are still going to be wired as 1-bank. The 2-bank, 20A NOCO is the way to go. Mine lasted 4+ years whereas the ProSport chargers I had before were only good for a couple of seasons before they failed.

[Onyx Z]

Even if you add another battery (3 total), your (2) stereo batteries are still going to be wired as 1-bank. The 2-bank, 20A NOCO is the way to go. Mine lasted 4+ years whereas the ProSport chargers I had before were only good for a couple of seasons before they failed.

After reading a lot more into it, this is the way I'm leaning. Thank you all!