Adding solar - Replace battery charger or just add inverter

[Bakoboat]

Looking for advice.

I have a 456 year 2000. This boat does not have an inverter just battery charger. I want to add solar to avoid running geny (or at least limit the time it is running) while anchored. The purpose of solar addition is to operate my fridge (which is ac only) and maybe another outlet for computers etc.

I am trying to decide if I should replace battery charger with a new unit that is a battery charger/inverter, thus tying solar into the boats entire electrical system, or just keep the present design and add an inverter and enough batteries to run the fridge independently while not on shore power.

I have lots of room to mount solar, house batteries and could easily arrange inverter installation beside my fridge enabling me to plug into shore power/geny or switch and plug into inverter/solar.

Any past experience/ideas will be appreciated.

Thank-you

[Midnightsun]

I would try to keep it simple if you are really only interested in the fridge while away from shore power as a full inverter system gets quite complex and rather expensive. My advice would be to increase your house bank size and use a small inverter at the fridge only or in others words convert your fridge to run off DC. Solar can be added if so desired for extending battery time while on the hook. A good size battery charger such as at least 60a will also get the juice back in quicker when you do need to run the genny.

Lots of options, all depends on the amount of time and money you want to invest.

[bud37]

There is one thing to remember, whatever power reserve you use from your battery bank has to be put back. Try to calculate your use is in amp hours....how big your battery bank will need to be in amp hours....then how to recharge. For example if you use a 60amp charger, it will not charge at 60 amps unless the bank is dead or near that. As the bank gets charged the amp rate drops down significantly due to bank resistance, something to consider when you calculate genny running time.

Hans has some good advice here.

[Rocketman]

I would recommend a couple of 195 watt solar panels and a whole boat inverter. Works great for me.
A new charger/inverter that can put out 60 amps is not going to be cheap.

I purchased this pure sine wave inverter that comes with the on/off remote switch and battery monitor.
https://www.amazon.com/gp/product/B07MTXZVBJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I also wired mine in with a relay to the generator breaker on the main power panel.
[url]https://www.amazon.com/gp/product/B07FCJFGL9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1[url]
This way when the generator is on - the relay automatically disconnects the inverter.
I also wired to the output of the inverter off this relay to additional small relays to turn off the battery chargers and the hot water heater automatically. This way you don't get a large load from the water heater and a never ending circle of current from the chargers trying to charge batteries from the batteries.
[url]https://www.amazon.com/gp/product/B087G6D24G/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1[url]

You can get marine 2/0 cables from west marine or ebay (there is a company here in the US) with ends already installed.

Came to about $400.00 w/ wiring and everything. Now I have whole boat Pure Sine Wave inverter system for TVs, Coffee, Blender, even microwave for a couple minutes.

I also have two solar panels on the hard top to keep everything charged during the day putting out 20 amps on a good sunny day.
Just make sure you use large enough cable from the controller to the battery connection (8 gauge wire is recommended if you have any length to run).

[bud37]

On further thought it may just be wise to replace your 120AC only fridge with a good marine AC/DC fridge....solve a lot of issues and increase the boats value. You are sure it is only AC as these boats would have come with AC/DC fridges I believe.

Also consider if it is 120 and has been refitted it may be a residential unit. In that case it may cause problems for you if it is not wired correctly.

[Bakoboat]

Thank you all for the replies, as Hans said, lots of options, lots to think about for me.

This forum is remarkable, so much experience and knowledge available and all so willing to assist, awesome!

my fridge freezer are two separate units sitting on top of each other, they are labelled carver and the specs match the owners manual so I’m assuming they are original. They are ac only based on units labels. I will be replacing them as the compressors are grumbling now and am opting for a modern ac unit. I figure the money I would save vs purchasing a ac/dc unit will pay for solar panels and inverter.

Was surprised this boat was built with ac only refrigeration and also without inverter. Research I have done indicates these boats were built to be using shore power or running the geney when underway.

I live aboard and anchor out regularly for days at a time, running the geney to keep the fridge at temperature is not something I want to do so will be installing solar for sure.

Just need to decide on the many options to proceed.

Thank you all.

[Midnightsun]

A boat from the factory with AC only fridge would be something I never heard of. This would mean every time you leave the dock you lose your ability to keep the fridge running. Just does not make sense. Regardless, you are going to replace it with a "proper" boat fridge meaning it will run off of both AC and DC. Cannot even imagine Carver would do something like this on such a large boat which is not all that old being a 2000.

Not familiar at all with a 456 however it does look like a very rare bird according to this post. Would not surprise me if your boat is one of these. viewtopic.php?t=35

Oddly enough this is the same boat being talked about in the link I posted above. Nice boat by the way. https://dailyboats.com/boat/280002-buy- ... t-for-sale

[Viper]

It's not at all uncommon to run across boats of all brands with AC only fridges, I've been on many. Most eventually end up with an inverter install. Whether you should go for a fully integrated unit into ship's systems or a dedicated one for the fridge only, which is a good inexpensive option by the way, really depends on your boating habits and pocketbook. A proper marine rated inverter that ties into the ship's systems with auto switching is not cheap to begin with, and the supporting hardware is expensive as well, not to mention labour if you go that route. If you have someone else install it, the cost of the hardware and labour will likely be as much or more than the unit itself depending on the install.

If your fridge is on its way out, and you don't need an inverter for anything else, spend the extra bucks an get an AC/DC unit, it's idiot proof and requires simply running DC wiring to the fridge location, and a breaker at the panel to make it happen. It'll switch to operate on AC or DC automatically depending on whether you're hooked up to shore power or running the generator. Check the DC breaker panel for a refrigerator breaker, check in behind the fridge, you may have DC roughed in.

What make and model charger do you currently have? If it's a more recent smart charger with decent output, then it may suite your current needs. Mine is a 60 amp unit which works fine for me. I don't have a central inverter or solar panels though panels are on my bucket list. I do use small, dedicated inverters for TVs and laptop. I exercise power management on the hook, and usually run the genny in the morning and evening for a couple of hours at a time. During that time, I heat the water, charge the batteries, make coffee, dinner, and whatever else needs to run on AC. I am planning on a dedicated inverter for the microwave because we find ourselves needing to run it periodically, but I don't want to have to start the genny to run the microwave for 30 seconds.

You can approach the solar installation separate from an inverter install. Focus on your fridge first, then go from there.

[Capt'n CRUNCH!]

Hello everyone - a somewhat similar (charging choice) conundrum here...

Yesterday I ordered a #49 Isotherm fridge (with freezer section) that is indeed 12/24 volt or 115 volt @ $1,900 with tax and shipping (ouch). I had planned on adding two or four flexible PV panels and one more house battery to buffer the new fridge load, and the new powerful LED light bar + the electric windless that I am excited about, (but haven't found yet). Flexible PV's for the top of the Bimini, as I trailer the 26' footer..

But then, last night, it occurred to me, perhaps it would be way more cost effective, AND simpler to just add another alternator with internal regulator to the 350 Chevy (plenty of space to add one on the Port side), and just add Two batteries - essentially creating a wholly separate new 'house' battery circuit, but with two batteries. This may be an adequate solution to not worry about impacting the existing battery(s) that are plenty good to handle the normal, nominal load. (Meaning not connecting to the stock system at all.) With the 'new' bank of two batteries it should be enough to carry me through overnight, and I wouldn't really be too concerned about running the deep cycles down - and even when on multi day trips I usually start the engine for at least a short cruise each day...thus charging both 'systems'.

Thoughts anyone? Thanks in advance!

Mark

[km1125]

Source of the post ...
But then, last night, it occurred to me, perhaps it would be way more cost effective, AND simpler to just add another alternator with internal regulator to the 350 Chevy (plenty of space to add one on the Port side), and just add Two batteries - essentially creating a wholly separate new 'house' battery circuit, but with ""two batteries. This may be an adequate solution to not worry about impacting the existing battery(s) that are plenty good to handle the normal, nominal load. (Meaning not connecting to the stock system at all.) With the 'new' bank of two batteries it should be enough to carry me through overnight, and I wouldn't really be too concerned about running the deep cycles down - and even when on multi day trips I usually start the engine for at least a short cruise each day...thus charging both 'systems'. ...

That can certainly be done, but you have to work on the "recharging" part, especially if you're using any kind of lead-acid batteries. They really don't recharge fully quickly. You can get a bulk charge back into them, but that only gets them to maybe 80% full, then it takes quite a while to get that last 20%. If you went with a lithium battery then it could charge much quicker, but also won't suffer any long-term damage even if you NEVER get it back to 100% (in fact most lithium batteries DON'T want to be at 100% very often!!). You'd also have the advantage of being able to run to lower discharge points, rather than the "generally accepted" 50% depth-of-discharge associated with lead-acid.