A few refit questions

[RGN]

Okay folks, as you all know fitting/refitting a boat is expensive and time consuming. I'd like to tap into the collective knowledge here and bypass an expensive mistake or two.


1. Bulkhead heaters: Does anyone know of an oil fired bulkhead heater that has a combination exhaust/intake stack? I like the Scandinavian/Finnish heaters but would really like to do away with the open vent thing.


2. House batteries: Will a few months difference in installed age make a real difference in Lithium house bank? I would like to install one now and then add another one or two in early summer, does that matter or should I just find a FLA for now and wait on the Lithium's?


3. Fridge sizing: I was hoping to use ice and a cooler originally but that damn cooler is just always in the way and not very secure. I have a huge old built in icebox. I could use the space to rebuild into a well insulated, much smaller refrigerator. So I am looking for suggestions on what size folks find adequate for a crew of one or two? Not looking for a freezer as much as cold beer and ability to keep perishables for more than a couple days. Sizing suggestions could be in cubic space or equipment cooling capacity.


Any thoughts or equipment suggestions are welcome. Thanks

[coopec43]

Fridge sizing.

I found this article to be helpful.
https://www.tradeboats.com.au/tradea...idging-the-gap


House batteries
I'm well and truly out of my dept here but apparently you should not mix batteries of different ages but a few months?

Here are a few links.

Mixing new and old lithium LiFePo4 batteries — northernarizona ...
https://forum.solar-electric.com/discussion/.../mixing-new-and-old-lithium-lifepo4-bat...
Dec 19, 2017 - Mixing new and old lithium LiFePo4 batteries ... be good to mix internal to a bank different age batteries unless the BMS was designed for it. 0.
Have Lithium Ion batteries come of age for off-grid systems ...14 Jan 2017

Why should not batteries of different age be connected in parallel ... 10 Jul 2014

People also ask
Should lithium batteries be fully discharged?
Can you mix old batteries with new ones?
Can you parallel lithium batteries?
How long do deep cycle batteries last?
Is it bad to use two different brands of batteries?

power supply - Why is it bad to mix new and old batteries ...
https://electronics.stackexchange.co...new-and-old-ba.



Bulkhead oil heaters
I can't help you with Bulkhead oil heaters

Are you aware the AYBC has changed it's requirements for CO2 Detectors?

Maybe something here?

http://www.cruisersforum.com/forums/...r-70311-3.html


https://www.sailingtoday.co.uk/gear/...-buyers-guide/


Clive

[Checkswrecks]

I've done a lot of failed Li-ion battery exams and with the Li-ion batteries, it's not so much that 2-3 months of calendar age will make much of a difference, it's that they will have aged differently and that may accelerate one's failure.

The anode and cathode surfaces in the individual Li-ion cells are very particular about depths of discharge, discharge rates, temp, etc. What is happening on a microscopic scale is that the anode/cathode surfaces look a bit like a Scotchbrite cleaning pad with their extreme porosity. Transfer of electrons during charge/discharge cycle leave deposits which inhibit function by coating the active material. We simpletons just refer to it as aging.

A nice slow use of a battery cell will allow the deposits to be spread more fully throughout the pores, while a sudden hard usage leaves the deposits building on the surface, choking access to the depths of the microstructure. It's one reason that the end cells will generally age slightly faster than the internal cells.

Suppose you buy the first battery and use it very gently or even just store it someplace which gets warm and the aging process allows those deposits to saturate over the months. Now hook up the second battery in parallel and the electrons of charge/discharge will go where it is easiest for them. The second battery will age faster, because the slightly greater resistance (deposits) in the first battery will make the second battery work harder, meaning there's a faster coating of deposits on the surface and less depth of saturation.

If you store the first battery somewhere cool and don't use it you probably would get away with a couple of months difference in calendar age with no issue. But for the price of these things it'd be better to just do the right thing. Buy and install them as a set.

Looking forward to others answering about the heater and fridge, but I will help drink that cold beer.

[WSMFP]

Originally Posted by RGN

3. Fridge sizing: I was hoping to use ice and a cooler originally but that damn cooler is just always in the way and not very secure. I have a huge old built in icebox. I could use the space to rebuild into a well insulated, much smaller refrigerator. So I am looking for suggestions on what size folks find adequate for a crew of one or two? Not looking for a freezer as much as cold beer and ability to keep perishables for more than a couple days. Sizing suggestions could be in cubic space or equipment cooling capacity.

I have a well insulated fridge that was previously an ice box. It measures approximately 24 inches deep and 30 inches long. With one side concave to the curve of the hull side. I installed a Isotherm 2501 air cooled system with a O shaped evaporator. Even in Florida summer it works great and will freeze anything I place inside the evaporator O or even near it after about 2 hours. You could easily make ice in some hanging or sealed ice trays and I sometimes buy ice cream sandwiches to bring with us over the weekend. It keeps them frozen solid. The compressor is in the lazeratte and it was very easy to install and run the lines. You twist the refrigerant line connectors together and its precharged.

[wrwakefield]

RGN,

I have had many differnet bulkhead diesel drip heaters on various boats over the years. I'm not aware of any manufacturers that combine intake and exhaust into one doublewalled flue assembly, but keep looking as I haven't in years...

I suspect this is because the cooler incoming air [typically the outer section of double flues— like propane heaters and some forced air diesel heaters— would cause more build-up on the inner exhaust stack flue lining with diesel exhaust (not unlike creosote build-up on uninsulated wood stove flues in cold climates.)]

That said, I have had double walled flues [i.e., intake and combustion air combined] on forced air diesel heaters in the past, and they worked great; but those are fan forced combustion systems, not convection like most drip heaters.

What I ended up doing was installing a heater that allowed me to run a seperate flue for combustion air, effectively sealing the heater intake/exhaust from the inside of the boat. This is also important to help prevent sooting the inside of the boat when a gust of wind reverses the draft on the running drip stove— especially when the gust snuffs out the flame... [What a mess!]

Here is an excerpt from one of our posts about living on a boat in cold weather:

Having had a stand-alone diesel drip unit in a 37ft boat at 61N over several winters, I can tell you you need one that balances intake draft so it won’t back-wind and soot up your cabin. (Sigmar was the only brand I found back then that had a separate combustion air intake among the diesel drip heaters… there may be others now…) I can also state that even with fans and air circulation, you won’t achieve even heat through-out the boat when it is cool outside. My boat was insulated and conditions often reached -20F with 40+ kt winds for weeks on end… I stayed warm, but not every nook on the boat was cozy…

In case any of this applies to you.

Best wishes with your projects.

Cheers! Bill

[RGN]

I am much amiss for not thanking you folks for your input, all of which was very pertinent and valuable.


I did indeed fine most of what I was looking for from your answers. Thank you.

[rbk]

There is little danger of co poisoning with a vented appliance with nondedicated combustion air. The exhaust run is short and stack effect and rising hot air make it very difficult to ya e combustion gases come back into the cabin. Think of standing on a ladder and trying to push a helium balloon to the floor without descending the ladder. And chances of depressurization your boat are low.