Three Batteries

Big Duck has three batteries.
Start
House
Inverter
These are three different batteries. The start is a 24, the house is a 27 (both wet) and the inverter is a 31 AGM.

I charge all three from a single charging source via 2 VSR's from Yandina.
Yandina VSR
When the Yandinas are in the AUTO mode, any charging source will be distributed to all three batteries. This charging source can be:
Onboard charger
Inverter charger
Engine alternator
Experts will tell you that this is not a sound practice - only batteries of identical size and age should be charged by the same source. I'm violating that rule on several accounts for the sake of economy and simplicity.
My take on batteries

Most of the time I have all the batteries combined via the Yandina AUTO function and because I'm so lackadaisical about my charging methods, I needed a way to see if one of them is heading south.

My first thought was a single voltmeter with a triple throw switch that would show each battery one at a time. Then I stumbled on these little gems on ebay...three for under $25.

So then all I needed was a lead from each battery to a three pole switch (because voltmeters will draw a battery down) and then to these voltmeters. These switches are readily available.

 

So now, if I set the combiners to OFF, I can see the voltage of each battery and how it's holding up after a load is applied.

 In the Yandina combined position, of course all the meters will show the same voltage if a charging source is applied, but if the Yandinas are forced off and no charging source is present I can get a feel of how each battery is holding up.

Would the right thing to do be having all the batteries identical and of the same age? Well maybe, but until then, I'm covered.

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Here's a comment on this approach from another board:

So I read Jeffs article and disagree with his modus operandi. Firstly, deep cycle batteries charge differently than start ones, secondly, different types of batteries should not be charged on the same cycle and thirdly AGMs take charge at a higher voltage and in most cases should never be equalized unless okayed by the MFGr. The Yandina combiner is basically to keep a troll motor battery charge, not for continuous use. More importantly, an external regulator is of essence on a boat which keeps the batteries at an optimum charge from variable sources.  

And here is my response:

Your point is well taken and I'll be the first to admit my approach to batteries is not ideal. But...my boat is over 40 years old and for some of us ‘bottom feeders’ the ideal approach is not always the best - we always look for something that just ‘works’. We know what the books say and how the serious boaters do it, but we opt to take a more casual approach. Before I bought my trawler I wondered how I was ever going to keep up with the high tech advice I got from every board. It was absolutely overwhelming…must have this…must do it this way…can’t be without this…this is what the books say -- and none of that ‘encouragement’ was cheap! I bought the trawler anyway but it was so much responsibility that it wasn’t any fun (even though it didn’t cost me a cent because it paid for itself by being in charter service). I found I didn’t want to have to worry about all those expensive elaborate systems. 

Today we have all the comforts of the trawler with none of the worries. She sleeps 7, has 2 mechanical steering stations, double galley sink, 4 burner stove and large oven, air conditioning and heat via a remote start Honda generator on the upper deck, microwave, fridge, freezer on the aft deck, hot water shower, gravity toilet, reliable 350 Chevy power for 25+ mph -- all simple systems that work day in and day out whether on the water, on the road or on the trailer in the back yard as a guest house. I’m certainly not knocking the folks who want to do it right, but if it ‘works’ and will get me out on the water, that’s good enough for me…and maybe also good enough for lurker/dreamers who hesitate to get their feet wet because they can’t manage to go the ideal route. 

My purpose is to encourage other (maybe lurking) simple folks to take the plunge. If you want to cross oceans, then listen to the big guys. If you just want to have some fun on inland and coastal waters, well maybe some of that high tech stuff isn’t all that important?

False Spring Weather

Around here in South Carolina, winter never really takes hold. We winterize our boats because sometimes the temps do get down into the teens, but it's only for a short spell. Sometimes in the later part of  the winter season the thermometer will show us 60° a few days after we experience the teens. It's awful tempting to take the boat out on those 60° days, but the reality is that there's still the possibility of needing to re-winterize 'cause those 20's could again be just around the corner.

I'm a sucker for the warm weather and just have to get the boat wet, but I'm also a lazy sob and don't want to re-winterize her in case the weather lures me out again. So here's what I do:

I put an electric heater in the engine compartment.

The heater is just to the left of the engine with the red indicator light showing that it's active.

 I know, I know, it's dangerous because a small spark when the heater cycles could cause gasoline fumes to blow the boat up. But I'm thinking that because the drain plug is out, those heavier than air gasoline fumes will drain themselves out. And in the cold weather I wonder about how much the gasoline will fume or if there is any fumes at all? I'd appreciate thoughts on these assumptions...

To assist the heater in keeping the mill warm, I made some covers for the engine room vents - these just snap over the engine room ventilation louvers.

Covers for the engine room ventilation louvers.

Then there's the question of how effective my efforts really are. Is the heater keeping things warm enough to prevent my block and manifolds from freezing and cracking? I solve this mystery by putting the sender for a remote reading thermometer in the engine compartment. This way I can see the temperature in the engine compartment from the comfort of my house.

It's 58.4° in the engine compartment - the ambient temp is about 32.

No matter what, it's a gamble I'm willing to take - the freedom of being able to take her out on a moments notice without being a hostage of re-winterizing.