Fridge extra power + adding heating & airconditioning ?

[The Finn]

Hi all,

I have this two folded upgrade problem to figure out, could you help out with some thoughts? I feel these questions should be addressed as an overall solution... So, I have four basic cranking batteries that seem to go low when I am off the dock, as I have no generator.

Mostly, I would need the power for the fridge or more specifically for keeping food cold. Also, I would like to extend the season with a heater. Rarely, but still, the nights can be warm, so why not go for an integrated heater & air conditioning. Well, that requires more power again, or would a diesel based system be an option (from the boat tanks? ) ?

I dont really fancy the generator route (or is this a misconception: noise, engine room space, high investment) . As the fridge is quite small in my 300 SD, would a 12v coolbox be a thought? Has solar or wind power developed enough to look into these as helping the coolbox directly or via the boat?

Duration for these needs is mostly just a night at a time. Air heating & cooling, we are not talking big temperature figure issues. Budget: as need is occasional, cant see myself investing hugely into this.

So, as you can see, thoughts are quite mixed. As always, all input is valued

Cheers, The Finn

 

[bobeast]

HVAC is going to be a deal breaker without a generator.

There is no reason a marine fridge should not run for several days on a fully charged battery bank. You mentioned 4 cranking batteries. If that us truly the case, you are not really setup properly for overnighting. For starting duties you should have dual purpose batteries. Your house bank, if not used for starting should be deep cycle, else dual-purpose.

The typical battery configuration from Sea Ray is a single dual-purpose battery that starts one engine and supplies power to the helm. Then two or more batteries in parallel as your house bank and to start the other engine. If you have 4 batteries, you'll need to tell us how they are configured and what type they are before we can be of much help.

For heating you might consider the Heater-Buddy which uses disposable propane canisters. They have oxygen and tip sensors and should be safe in an enclosed space as long has you leave a vent open. You're SOL as far as cooling unless you add a gennie or a massive battery bank with an inverter.

Some folks have added solar on top of their canvas to offset fridge use, but really, for one or two days you shouldn't really need it with a properly functioning house bank and charge system.

If you like to crank your stereo while at anchor it will drag down your batteries. Of course that would serve you right for disturbing the rest of our peace and quiet

Also consider changing out all your interior lights to LED bulbs. That will save quite a bit of battery.

 

[The Finn]

Thanks for your input! Just checked my port batteries and they as good as gone. They do still Load up fine, but drain out quickly, and where at 10,5v. Starboard side are at 12,6v. So I guess this is a good time to make changes.

I'll have it done by the local Marine Shop, but I wan't to have a better understanding of options. In the pic is the current set up. First objective will be to apply a normal set up with ample power for the fridge etc, forget airconditioning for now, start looking into heating options.

 

[Stee6043]

Heating options = more blankets and a friendly first mate/admiral!

They do make indoor "safe" propane heaters but I don't think I'd really want one onboard my boat. They generate a lot of moisture (I believe) and the thought of open flame onboard....I'm not sure I'd sleep well

https://www.amazon.com/Mr-Heater-F2...ropane+heater&qid=1565089575&s=gateway&sr=8-3

 

[andy k]

Since you have a diesel powered boat I would recommend a webasto diesel furnace for those cool nights. https://www.webasto-comfort.com/en-uk/product-overview/product/show/air-top-evo-40/

I use a solar panel to recharge my batteries during sunlight hours. This is a inexpensive investment to keep your batteries topped off. I spent a week on the hook and used this product and never had to run my generator for power needs. However if you are just spending 1 night not on the dock and are having issues with your batteries you more than likely have bad batteries or have an unusual power draw somewhere.
https://www.amazon.com/DOKIO-Foldab...ocphy=9019064&hvtargid=pla-386185054042&psc=1

 

[bobeast]

Thanks for your input! Just checked my port batteries and they as good as gone. They do still Load up fine, but drain out quickly, and where at 10,5v. Starboard side are at 12,6v. So I guess this is a good time to make changes.

I'll have it done by the local Marine Shop, but I wan't to have a better understanding of options. In the pic is the current set up. First objective will be to apply a normal set up with ample power for the fridge etc, forget airconditioning for now, start looking into heating options.

It looks like you have two banks of 2 paralleled batteries each. Its not clear to me which is considered the "house" bank (which bank runs your fridge). It looks like these are rated at 110Amp hours which, when new would give you 220 AH per bank. That should be more than enough to keep your fridge running for a day or two. That said, those are Walmart specials and as such, it's likely the ratings on them are ahem....optimistic.

Good quality AGMs should be your next investment. Then make sure the onboard charger is up to the task. If you post a picture of your charger some may chime in as to its relative quality.