House batteries and cranking battery charging configuration

[stackwalker]

I've got a '99 Hunter 410. I've been going through and fixing all the things for the last year since I bought her. After a couple longer sailing outings I've learned that the house batteries only charge on shore power, not when unplugged and the engine is running. The cranking batteries don't charge on shore power, only charge off the alternator.

I haven't spent much time tracing all the wiring from the inverter and draw selector switches yet. This heartbeat system is not super intuitive to me yet. I've checked the manual and I've gotten the impression that the house batteries should charge from the alternator like the cranking battery does.

 

[Davidasailor26]

There are a few ways the batteries can be wired to allow different charging configurations. Some boats have a 1-2-Both switch to select the battery for the loads and charging. Some have battery isolators or automatic charge relays that combine the banks when they’re charging. On a 27 year old boat it’s hard to say what yours may have had or what other changes have been made along the way, so you’ll probably need to trace out wires and see what equipment you have. Then you can figure out whether something has failed or if that’s just how it’s wired, and what you should change to make it better.

 

[dlochner]

A good resource for understanding and designing battery systems and their components is MarineHowTo.com.

Take a look a the articles on alternators, different types of batteries, and the 1-2-Both switch.

Marine How To - DIY for Boaters - Marine How To

For DIY boaters in an attempt to try and keep the sport as affordable & safe as possible. How To articles for sailboats and powerboats.

marinehowto.com

 

[lemoiney]

As https://forums.sailboatowners.com/members/davidasailor26.63309/ said, you’ll need to do your research here. A quick AI search indicates that ACRs (Automatic Charging Relay) were introduced in the mid to late 90’s. I have a 2015 Hunter and its ACR failed after only 2 years. A very easy replacement. I also have a 1-2-Both switch. The systems are not complex, but as davidasailor26 said, “On a 27 year old boat it’s hard to say what yours may have had or what other changes have been made along the way, so you’ll probably need to trace out wires and see what equipment you have. Then you can figure out whether something has failed or if that’s just how it’s wired, and what you should change to make it better.” If you’re not familiar with marine DC charging systems, I suggest you find a marine electrician to sort it out and make it right.

 

[stackwalker]

I guess I was looking for other 410 owners specifically to see if they had any tips on the heartbeat system. I've had boats with the 1/2/both setup and it was much simpler and easier to troubleshoot. I'm sure when it was new it was all very seamless and easy to use, but now that things have failed and been replaced by varying levels of skill, who knows.

I'm a 14 hour drive from my boat, but heading back down there in a couple weeks to spend a month fixing and repairing. Hopefully I can figure it out without paying someone.

 

[JamesG161]

Hopefully I can figure it out without paying someone.

This is correct below

After a couple longer sailing outings I've learned that the house batteries only charge on shore power, not when unplugged and the engine is running. The cranking batteries don't charge on shore power, only charge off the alternator.

Hunter did have "House Batts charge from Alternator", but a relay failed too often.

I added a new Inverter/Charger [ICG] that uses shore power or my Genset when needed.

Jim...

 

[stackwalker]

So Jim - you're saying the charging scheme I've noted is the way Hunter intended on the 410?

 

[Stu Jackson]

A quick AI search indicates that ACRs (Automatic Charging Relay) were introduced in the mid to late 90’s.

This is a perfect reason to distrust AI. Why? Because Yandina has been making "Combiners" for decades. I bought mine in 1998, but had been reading about them in the West Marine catalog "Advisors" columns for years.

Combiner Information

AI is Slop!

 

[lemoiney]

This is a perfect reason to distrust AI. Why? Because Yandina has been making "Combiners" for decades. I bought mine in 1998, but had been reading about them in the West Marine catalog "Advisors" columns for years.

Combiner Information

AI is Slop!

Stu, regarding AI, I agree 100%. My point was only to indicate that ACR’s were around when the boat was commissioned and that their failure is a common reason for the charging scenario described.

 

[JamesG161]

So Jim - you're saying the charging scheme I've noted is the way Hunter intended on the 410?

YES !

Jim...

 

[stackwalker]

Is the expectation that owners just hook up solar panels with its own charge controller?

 

[jssailem]

It is not an "expectation". The original design of your boat did not consider solar panels.

Solar on boats is a recent development. While the panels will convert solar energy to electricity, you are going to need a charge controller to channel the energy into something usable by your battery.

 

[Stu Jackson]

Stu, regarding AI, I agree 100%. My point was only to indicate that ACR’s were around when the boat was commissioned and that their failure is a common reason for the charging scenario described.

Appreciated and understood.
I am, however, compelled to note that Yandina's controllers have a lifetime guarantee, that they do honor and that they have been in business making them for decades well before BlueSeas started with their copycat version. Yandina failures are rare. BlueSeas perhaps not so much based on your observation of failure(s). Thx again.

 

[marcham]

Did you figure it out?

Your OEM wiring design depends on wether the factory installed a charger/inverter or just a charger.

As mentionned, you most likely have a relay / ACR that should combine the start and house batteries when the engine is running. This relay (usually found behind the battery switches) is activated by the engine's ignition key. On my boat, it was activated by a circuit breaker instead, so we had to manually parallel the two batteries after engine start. If a previous owner upgraded to an ACR, it should activate automatically based on start batt voltage. ACRs (and standard relays) are a common single point of failure.

I'd suggest, when you are back at the boat, that you pull the battery switch panel and start tracing wires. The OEM wiring diagrams are actually pretty good.

 

[Pizzazz]

The setup should be simple and intuitive, with easily replaceable parts. My setup is:

1. Shore power goes to ground fault protection, then to the inverter/charger then to outlets
2. The inverter/charger is connected to engine and house batteries through an A/B switch.
3. The engine starter is connected to the starting battery only.
4. The alternator (and/or solar) is connected to the house battery only.

With this system, you only one A/B switch to operate (house most of the time, both when the engine is running, both when you have trouble starting on the starter battery). The downside is that you can run down your starting battery but that is rare.

Complications:
5. Relay to connect house to starting when the engine is running. This is a must if house is LFP.
6. You can move high loads (water heater, AC) outside the inverter circuit if you prefer

Avoid using ACRs, diodes, etc. on a single engine sailboat. ACRs work with specific voltages only, so not applicable to LFP. Diodes have a voltage drop which reduces the efficiency of the alternator. They are ways around these but they are costly and complicated.