Crazy way to design alternator charging?(Hunter 45CC)

[S/V Talisa]

Hi,
On my Hunter 45CC, the factory saw fit to insert a solenoid between the house and starter battery banks. The solenoid is energised by wire running from the start key in the cockpit.

So ... this means that whenever you are starting or running the engine, you have both batteries combined. Sort of defeats the object of a separate start battery, but there you go ...

This means that the 80A alternator is permanently trying to charge both the start and house batteries. However ... whilst the start battery is a regular AGM, the house bank is specified as a 2 x 4D Gels. We all know that Gels need special voltage regulation to avoid frying them so I don't see that a regular Hitachi IC regulated alternator on the engine is going to do them any good at all.

Anyone else see this as a problem or figured out a work-around?

BTW, the genius that designed the AC panel decided that no AC can flow round the boat until the relays in the panel are energised by 12V. If the batteries are flat, you don't have 12V to energise them, hence you can't use the 120V battery charger to charge the batteries and therefore you can't get the AC to come on ....... <repeat>

 

[Jeff Jellick]

ST, what year is your Hunter 45 CC
Jeff
SV Sooooo Lucky
Hunter 45 CC

 

[Ward H]

On my Hunter 45CC, the factory saw fit to insert a solenoid between the house and starter battery banks. The solenoid is energised by wire running from the start key in the cockpit.

Talisa, are you sure that the wire from the solenoid to the start key is wired to the ignition/run post of the key switch? I believe it should be wired to the "start" post of the switch. When you move the switch to the "start" position power to the wire makes the solenoid drop out so the batteries are not combined when starting.
Thats how the Blue Sea Automatic Charging Relay (ACR) works.

 

[S/V Talisa]

Hi Jeff - 2006
Ward H - Actually, I'm not sure what post it's wired to as the wiring diagram is entirely sketchy showing just a wire going to the key switch. The intent seems quite clear though, parallel up the two banks when the engine is running so that they can both take a charge. AFAIK, the solenoid is NO (Normally Open) and needs to be energised to pass current, so wiring it to the 'START' position would, indeed, connect both batteries when starting, however, I believe that it's most likely that it's actually wired to the RUN position.

Either way, my point was that Hunter seem to have contrived to charge a couple of 4D Gel batteries using a regular Hitachi 80A Alternator normally as supplied by Yanmar (as opposed to an externally regulated one like a Balmar) when the engine is running and this doesn't sound like a particularly good idea.

Having said that, the 4D Gel battery bank has held up well, so I'm mulling over if this is really an issue at all.

I have to make a decision within the next couple of days whether to install new Gel or AGM batteries and that's what's driving this line of enquiry.

 

[DayDreamer41]

@S/V Talisa when you refer to, "AC" I presume you are talking Alternating Current and not Air Conditioning?
I am going to have to try something this weekend coming when I am at the boat to continue on my list, but I am almost certain that to power up the 120 V AC panel all I have to do is close the breaker and I am pretty sure that the charger powers up when that happens. In other words there isn't a 12V relay that has to energize to power up the charger as long at the DC main breaker and main DC switches are closed the charger will start.
As for the different charging curves you may want to do a bit a research into the finer art of battery charging. Near as I can tell there really isn't that much difference between the Gel and AGM charge profiles especially when you are charging with an internally regulated 80 A (may be generating 50 A) alternator, I would bet that unless you are motoring for hours at a time you will never get your batteries back to 100% SOC. As a minimum you could remove the alternator and either DIY or take it to an alternator shop and have them defeat the internal regulator and then install an external unit such as the Balmar MC-614.
https://marinehowto.com/programming-a-balmar-voltage-regulator/
Here is a good start
https://discoverbattery.com/battery-101/agm-battery-charging
And if this peaks your interest and you want to really dig into the nuts and bolts you can study here
https://marinehowto.com/installing-a-marine-battery-charger/
@Maine Sail not only provides the knowledge but also has all the equipment to make things right.

 

[Maine Sail]

Talisa, are you sure that the wire from the solenoid to the start key is wired to the ignition/run post of the key switch? I believe it should be wired to the "start" post of the switch. When you move the switch to the "start" position power to the wire makes the solenoid drop out so the batteries are not combined when starting.
Thats how the Blue Sea Automatic Charging Relay (ACR) works.

To pinch pennies Hunter used basic automotive solenoids for this, not a Blue Sea ACR. Marlow started using ACR's, but many Hunters were wired with an automotive solenoid and the alt feeding start bank first with the solenoid excited by the key on position.

 

[Maine Sail]

Either way, my point was that Hunter seem to have contrived to charge a couple of 4D Gel batteries using a regular Hitachi 80A Alternator normally as supplied by Yanmar (as opposed to an externally regulated one like a Balmar) when the engine is running and this doesn't sound like a particularly good idea.

Having said that, the 4D Gel battery bank has held up well, so I'm mulling over if this is really an issue at all.

I have to make a decision within the next couple of days whether to install new Gel or AGM batteries and that's what's driving this line of enquiry.

You're quite lucky the 80A Hitachi is such a poor alternator for charging deep cycle batteries.. In your case it has meant you have not yet cooked your GEL batteries.

This article should help explain why: Automotive Alternators vs. Deep Cycle Batteries

If you plan to stick with either GEL or AGM they really should have a good charging system. GEL batteries can last a very, very long time if charged properly. We have had one GEL bank go 17 years and numerous others go 10+.

Rx:
Route alternator charging to house bank (fuse within 7" of house bank +)
Install an external regulator, even if you stay with the Hitachi frame
Remove the key-on solenoid
Install a Blue Sea ACR, DC to DC charger, Echo Charger, Duo Charger etc..

 

[Dave Groshong]

We do offer a service, our expert here will help you overcome the situation:
https://shop.hunterowners.com/1to1.php

 

[Hunter Ad Bot]

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[S/V Talisa]

Thanks all for the replies.

DayDreamer41 - Yes, Alternating Current. Hunter had a number of different variants of the AC panel on the 45CC. The original design was 'over-thought' and had a mass of interconnected relays that tried to figure out where the power was coming from (shore / inverter / generator) and switch it appropriately. Unfortunately, all this complexity came at the cost of unreliability.

My panel had to be sent back to Ultra Panel Marine in FL at some large expense and when it came back it had been completely rewired. Others have bypassed this part of the panel completely in favour of a dumb shore/gen switch.

On your 41, the panel may be wired quite differently, but yes, on mine at least, I need 12V at the panel to energise the relays that bring the 110V into play. So NO DC = NO AC. As I leave the boat for long periods, quite often the batteries are insufficiently charged to allow the relays to activate, so I have to use a separate battery charger to put enough charge in before I can get the main charger to kick in.

Main Sail - Neglected to say that mainly, if I need a battery charge and I'm away from the dock, I mainly run the generator for a few hours as the most efficient way to recharge via the 150A Freedom inverter/charger unit. However, I do also run the engine for long periods (on the ICW mainly) and this could have an adverse effect on the batteries.

What I was most concerned about was a very poorly regulated alternator exceeding the max. voltage for the batteries and burning the Gel. As we know Gel cells are easily killed by this.

Bottom line seems to be that as marinehowto explains, the Hitachi is just not up to the job, so I need to investigate an external regulator.

FWIW, I found that Cole Hersee makes a voltage sensitive version of the same solenoid used on my boat (model
48525) . It looks like the just added a little electronic 'backpack' to the original solenoid. I've bought one and will be attempting to swap out the dumb relay soon and remove the wire from the start switch.

 

[Maine Sail]

FWIW, I found that Cole Hersee makes a voltage sensitive version of the same solenoid used on my boat (model
48525) . It looks like the just added a little electronic 'backpack' to the original solenoid. I've bought one and will be attempting to swap out the dumb relay soon and remove the wire from the start switch.

The Blue Sea 7610SI ACR is a better product for marine use..

Understanding Automatic Charging Relays

 

[S/V Talisa]

Maine Sail - ...and around the same price as well. D'oh. Wish I'd seen that before. The Cole Hersee though looks like a drop in replacement for the existing solenoid as the panel is constructed with heavy gauge copper bars going to the solenoid and it should be a case of just swapping one for the other. I'll let you know how it goes.

 

[DayDreamer41]

@S/V Talisa Heck I may also need 12 V to activate relays, I just have never heard any clicking of relays when I close the 120 V breaker, but that could be from the fact that I have never had dead batteries. Sounds like you have a big expense coming your way with the purchase of replacement bat's. Might be a good idea to make the necessary upgrades to the charging side at the same time.

 

[seadaddler]

Mainsail
Can you explain how to use a internal alternator and change to external regulated alternator.
I have solar charging my 4-6 volt wet cells and ACR charging my start batteries.
Nick

 

[DayDreamer41]

https://marinehowto.com/external-alternator-regulation-conversion/

 

[Maine Sail]

Mainsail
Can you explain how to use a internal alternator and change to external regulated alternator.
I have solar charging my 4-6 volt wet cells and ACR charging my start batteries.
Nick

We have decided to no longer provide instructions for the Hitachi frame alternators. We've sent instructions to about 30 people over the years and out of those 30, about 25 +/- wound up ruining their alternators attempting this on their own. Unlike the Leece-Neville 8MR series, which we do provide instructions for, the LR180 is a much more complex conversion to do correctly. It is quite often done incorrectly, or done in a manner that causes the field wire to short, which can destroy the regulator. Best to take it to a shop that can actually perform this modification, approx $75.00 to $150.00, or to consider one that is already specifically built for external regulation such as a Balmar or a CMI-80-ER.

 

[DayDreamer41]

Mainsail
Can you explain how to use a internal alternator and change to external regulated alternator.
I have solar charging my 4-6 volt wet cells and ACR charging my start batteries.
Nick

I found this old article on the Cruisers Forum
http://www.cruisersforum.com/forums...smart-regulator-instal-question-125843-2.html

 

[artboas]

We have decided to no longer provide instructions for the Hitachi frame alternators. We've sent instructions to about 30 people over the years and out of those 30, about 25 +/- wound up ruining their alternators attempting this on their own. Unlike the Leece-Neville 8MR series, which we do provide instructions for, the LR180 is a much more complex conversion to do correctly. It is quite often done incorrectly, or done in a manner that causes the field wire to short, which can destroy the regulator. Best to take it to a shop that can actually perform this modification, approx $75.00 to $150.00, or to consider one that is already specifically built for external regulation such as a Balmar or a CMI-80-ER.

Main Sail
As always, your responses are thoughtful and honest.
As you are aware from my posts, my electronics background is well established.
I see no point in taking a 80amp Hitachi and trying to make it do something it was never intended to do.
Bearing in mind of course that that rated number (80 amp) doesn’t take into account efficiency losses such as heat, brush wear, etc.
I support your decision not to guide people into converting these alternators into externally regulated alternators for the simple reason that they aren’t up to the job.
Here’s what people do on boats...
They throw in a bunch of extra batteries, and then expect that they will somehow magically get charged.
A 12v system needs to be rated not just on the discharge side, but charge side as well.
All components need to match.
That also applies to inverters.
It makes no sense to bodge together separate inverters and under-rated chargers , which inevidibly lead to a mish mash of breakers, poorly crimped under-gauge wire, etc.
There are several competent suppliers of charger / inverter systems; my favourite being Magnum energy.
There is no logical reason to try and “stretch” under-rated components when you can simply open a box, perform a ridiculously easy install, turn the switch, and forget about it.
You are going to spend the money on boiled batteries, and be constantly debugging a system that could be right from day one.
There are certain essential expenses on a boat, and trying to get a charger / inverter to magically exceeed its specifications is akin to mixing water with your diesel, somehow thinking that diluted fuel will still run.
You are in the marine business, and it’s much easier to make money from a customer whose system works because it’s supposed to; not because it’s being pushed beyond its limits, and requires repeated service.
I agree that Hunter’s original AC wiring was overly complex a few years ago, but they were dealing with the available technology. The reason they used automotive solenoids was simply because Blue Seas hadn’t developed the ACR yet.
The only comply with a combined was Heart Interface, and it was somewhat cumbersome. The ACRs nowadays are not even worth discussing the price of, as it’s insignificant in the scope of things.

 

[SEMPERAVANTI41]

I have a unique situation where the Hunter solenoid for connecting the start and house batteries may actually work better than a ACR. On my 41DS I installed a Mase 7.6 generator, which has it's own 35 amp alternator set up for charging a lead acid battery. I needed a start battery and the only one available was a lead acid at Wal Mart. Now when I run the generator it charges the start battery from the 35 amp alternator at the correct voltage, but it does not overcharge the house AGM batteries. I guess that when I run the main engine and the solenoid closes, the house bank will get some higher voltage from the start battery, but I cannot see any change on the voltage gauge.