Big electrical picture on a smaller boat help

[Sunsetrider]

I need to put together a plan for preparing my Albin 25 for The Big Adventure. In the luxury department. I am looking for some guidance as to where to go from here.
Existing setup:
- newly re-wired battery room with 1 start battery and 1 115AH house battery, controlled from the alternator with a Blue sea ACR, controlled from the deck with a Promarine Pro550 12A dual-battery smart charger, new 12V breaker panel, minimal draw on day trips. Plan to switch to LED lights throughout, including anchor light. 2 small 12V fans. Alcohol 2-burner stovetop, propane BBQ. Basic electronics, 2 12V plugins (cig).
New to come:
- Unique portable 60 l. fridge/freezer (2.5 AH draw, they say)
- would like to run a small M/wave, maybe a pressure cooker

So I bought a Generac IX2000 portable generator but have been convinced to bring it back. I learned that it wont be able to efficiently charge my batteries through the little 12A charger, so I would have to charge from the un-smart 12 VDC outlet on the genny anyway, the noise, the risks, etc. I have decided to go to more battery and more solar instead.

The fridge retailer also sells a 100A solar panel which I can maybe fit onto the bow area, but 2 smaller ones would probably fit better. I figure with the return of the genny I have $750 (CAD) freed up for battery and solar, so that should be plenty budget-wise. (?)

So thinking to link a pair of golf cart batteries in parallel to the existing 115 AH house should give me enough battery power? 100A solar should be able to keep the batteries up to speed with the fridge?

And a 2000W inverter to power the occasional 100V appliance.

Will this work?

[44'cruisingcat]

I'd suggest doing without the microwave.

More house batteries would be good too.

[Sunsetrider]

I'll drop the MW.
What do you mean by more house? Aren't there a variety of Golf Cart batteries available? Which size should I be looking at, to add to the existing 115AH?

[Pete7]

Is the 115AH battery fairly new? if so add another rather than replace with T105s. You can do that in 3-5 years when they start to fail. Add more solar, like 200w and see how you go. We have managed with 140w of solar for fridge, tv, laptops and lights etc but that is in good sunshine. It all goes pear shaped with rain and heavy cloud. We are just upgrading to; well not sure but about 210w of solar.

Have you thought about using an alternator charger for when the main engien is running?

https://sterling-power.com/collectio...tor-regulators

Pete

[Sunsetrider]

Originally Posted by Pete7

Have you thought about using an alternator charger for when the main engine is running?
Pete

I have not heard of those, and not sure what they do. I'll look it up. I know that the alternator does charge the batteries while underway, so not sure what those things do.

My house battery is only 2 years old but I prefer to upgrade while still earning money rather than afterward. And rather than putting in another big heavy thing. Your info about your current solar/fridge setup is helpful. I think I can get away with 200W solar based on your info.

[smac999]

You can't add golf carts to your existing house battery. Remove existing and but in new golf carts.

More battery only helps if you get back to dock charge each trip. Otherwise you also need more charging.

Your alternator charging is fine.

To run the inverter you'd want at least 4 golf carts

Your 12a charger is tiny and useless. If you add more house batteries you need a bigger charger. (Asumming it gets plugged in)

[sstuller]

Your panel capacity is based on your average daily consumption. A 135 watt, 12 volt nominal panel will give you 40 AH (amp-hours) per day on average. So your first task is to determine your average 24 hr consumption in amp-hours. If its 80 AH then you need two 135 watt panels. Your minimum battery 20 hour capacity should be twice your average daily consumption given a 50% DOD (depth of discharge). Thanks.

[Sunsetrider]

Originally Posted by smac999

Your 12a charger is tiny and useless. If you add more house batteries you need a bigger charger. (Asumming it gets plugged in)

What size charger is reasonable? 20A?

[hobopacket]

Are you going to be plugged into shore power daily? If not your solar controller/charger needs to match the most output you can get from your solar setup. Also agree ditch the microwave. Figure up all the amp hours you will use in 24 hours and go from there. You want to be in the situation where you can sit at anchor for a week and not have to worry about running the engine. Best bang for the buck are good ole fla batteries.

[sailorchic34]

As I sit at anchor, day after day, this is what I recommend. You will need at least 240 watts of panels ( I recommended 300 watts minimum with refrigeration) and four GC2 6V batteries ($90 each at costco) wired two sets of two for a total of 440 AH of which 220 AH is safely used.

Your fridge alone will need at least 60ah a day, more in hot climates

Why so many panels, because a 100 watt panel only outputs about 65 watts in bright sun on a boat at anchor. Shading 1/2 of one cell would drop output by 80%. Shading is a HUGE issue on a sailboat So 2-3 panels in parallel is highly recommended. I have 340 watts that gives me about 220 watts of real world output for 4-5 hours a day. But I have a high speed laptop that needed one panel just for it.

Loose the microwave. Your boats too small to give up that much space to a more or less useless appliance. Use a dutch oven pan for baking on your two burner stove top.

[Sunsetrider]

The microwave was a momentary whim.

[Pete7]

Hobopacket has mad a good point about knowing your power needs. To add to this you also need to monitor the batteries day to day. Fail to charge them sufficiently or run them down too low and they will fail in short order regardless of how expensive they are or how many dilithium crystals they contain. The cheapest option is something like this:

Clipper BM-1 Battery Monitor - Nasa Marine Instruments

Available in the US for a damn sight less than the UK price

[Sunsetrider]

Thanks Pete - I do intend to get some kind of battery monitor. But I need to keep in mind that I am a small diesel cruiser/trawler, not a MV nor a sailboat. I don't want to get too big for my britches in the power dept. 4 GCs, a 20A or 50A charger and 100W solar is probably the best I can manage.

[sstuller]

A folding solar panel can augment your 100 watt panel on days of heavy battery discharge. It has the virtue of allowing you to adjust its' orientation toward the sun. Once the batteries are up to snuff you can store it below since its' output is only needed occasionally.

[Pete7]

Originally Posted by Sunsetrider

Thanks Pete - I do intend to get some kind of battery monitor. But I need to keep in mind that I am a small diesel cruiser/trawler, not a MV nor a sailboat. I don't want to get too big for my britches in the power dept. 4 GCs, a 20A or 50A charger and 100W solar is probably the best I can manage.

Quite agree, you like us don't have the space or the need for a huge system of batteries and charging etc, hence why I suggested something like the NASA monitor, simple, small and does what it says on the box.

The other widget I suggested for the alternator could be useful if you intend to motor regularly. You would be forgiven from thinking that with a depleted batter bank and the engine running a 60A alternator will have close to 60A of charging. Sadly The truth is somewhat different. A 60A alternator may start with a high charge but will quickly drop down and 30 minutes later you will be disappointed to see perhaps 30A and dropping still further. To add to the problem as the batteries are charged up the internal resistance increases so the amount of charge they accept is slowed down. Charging the last 10-15% really does take a long time but its key for long battery life. I watched our volvo take 10 hours to put 40AH into a 220AH battery bank whilst motoring across a flat calm English channel one year and was astonished how long it took.

So the answer is a widget that fools the alternator into thinking the batteries are really discharged and then holds the alternator at a high 14.8v charge for a long time. It might not sound much compared to say a standard 13.8-14.2 alternator but it is and for the price ($100) something to be considered.

Now, completely off topic but if you added some more solar you could run a slow cooker Just putting our system together now, but with 240w of solar we should have about 10A of charging. By chance we have a 240v 120w small slow cooker on board which will take about 10A at 12v, give or take. So if our battery bank is reasonably full by mid morning we could fill up the slow cooker with a curry and leave it to slowly cook all afternoon

Pete