Battery charging

[Mike H.]

We have a 2004 Hunter Passage 420 with a yanmar 4jh diesel. She has two batteries. Bought it last spring, one of the survey items was to replace the inverter/charger as it had in internal short. The electrician I hired to do the replacement told me that the house battery only charges from shore power and the starting battery only charges from the alternator.

Does that make sense, is this true?

 

[Don S/V ILLusion]

If the charger is connected only to your “house” battery And your “start” battery is connected only to the alternator, then yes. Everyone has their own preference for battery management but yours is strange.
my suggestion - build a 2 battery house bank, isolate a third as a dedicated start battery and connect all through an ACR or other relay combiner for charging from both shore power/charger and the engine alternator.

 

[jssailem]

Does that make sense, is this true?

True… If you believe the surveyor. Why would you tell you anything that he did not see. After all you paid him/her to tell you what they observed on your new to you boat.

Make sense? As @Don S/V ILLusion clarified… A battery charging system is what ever the builder/previous owner decided. Only you can decide if it is right for you.

Personally, I modified the electrical system that I found on the boat to match the design elements identified by Don. That structure makes sense to me.

 

[sailing gal]

We have a 2004 Hunter Passage 420 with a yanmar 4jh diesel. She has two batteries. Bought it last spring, one of the survey items was to replace the inverter/charger as it had in internal short. The electrician I hired to do the replacement told me that the house battery only charges from shore power and the starting battery only charges from the alternator.

Does that make sense, is this true?

I have a 410 and that I bet is wrired the same. There are 2 different wiring methods depending on whether your boat cam from the factory with the charger inverter. Since it sounds like it did then if your boat ios like mine the charger goes to the inverter selector switch and charges whatever bateries are selected on it. But there is a line from thje switch that goes to an isolator diode that goes to the start battery also, so it also charges. The alternator also goes to that isolator and charges to the start and to what is lined up on the inverter selector switch

 

[dkinzer]

My 2007 H41AC has a large solenoid switch on the back of the panel that has the big battery switches on it - on the end of the seat at the nav station. The house battery is connected to one side of that switch and the starter battery is connected to the other side. As it came from the factory, that solenoid switch was energized when the engine switch in the cockpit was turned on. This effectively connects the start and house banks in parallel when the engine is starting and running, allowing the alternator to charge both banks. The attached photo shows how this looks with the panel tilted out and looking down from above. The energization wire is currently disconnected because I installed a Blue Sea Automatic Charge Relay that takes the place of the solenoid switch. The ACR allows the alternator to charge the house bank and also allows the Xantrex charger/inverter to charge the start battery.

By the way, my Xantrex charger/inverter has an "echo charge" output that is usually connected to the start battery. I haven't gotten around to disconnecting this yet but plan to do so because it is superfluous now that the ACR is installed.

If it is true that you boat has neither the solenoid switch nor an echo charge output from the charger/inverter, then what the surveyor said is probably true. An ACR will solve that problem and is fairly easy and inexpensive to install. I should mention that in the photo of the ACR, the black box in the upper left is the ACR itself and the two fuses below it connect to the start and house banks. The two fuses to the right are to allow a solar controller to charge the house bank (and via the ACR, the start bank, too).

 

[JamesG161]

On my H430...

1) Alternators charge the Start Battery, normally
2) My Inverter/Charger [ICG] charges the House Batteries.

told me that the house battery only charges from shore power

True, or other source of 120VAC.

Jim...

PS: We have a on board 120VAC Generator, thus no shore power needed.

 

[ice breaker]

On our 2004 41AC, the Yanmar alternator charges the start batery and once the Yanmar s running the combiner solenoid closes and drives charge to the house bank as well as the start batery. The solenoid does not close until the alternator is producing power.

An interesting aside is that our panda generator alternator only charges the start batery it shares with the Yanmar, and does not activate the combiner solenoid. With the genset running the 120v batery charger is filling up the house bank.

I am sure that that is how your system works. I have heard of the solenoids failing. It would be worth a look to see what you have and if it needs replacing.

 

[DRhoads]

I have a 2005 420. Starter is charged by solar power and alternator but not shore power. Shore power charges the 2 house batteries and the bow thruster batteries. The alternator charges house and starter and the generator charges everything.

 

[Mike H.]

Thanks everyone for your responses. I'll need to hire an electrician to sort out what I have.

 

[Davidasailor26]

If you’re not comfortable by all means hire a marine electrician, but try to learn all you can from them about how your boat is set up and how to maintain it yourself. The time spent learning will pay for itself many times over in ability to do future work DIY. Marine How To - DIY for Boaters - Marine How To and Nigel Calder’s Boatowner’s Mechanical Manual are a couple good places to start.

 

[artboas]

My 2007 H41AC has a large solenoid switch on the back of the panel that has the big battery switches on it - on the end of the seat at the nav station. The house battery is connected to one side of that switch and the starter battery is connected to the other side. As it came from the factory, that solenoid switch was energized when the engine switch in the cockpit was turned on. This effectively connects the start and house banks in parallel when the engine is starting and running, allowing the alternator to charge both banks. The attached photo shows how this looks with the panel tilted out and looking down from above. The energization wire is currently disconnected because I installed a Blue Sea Automatic Charge Relay that takes the place of the solenoid switch. The ACR allows the alternator to charge the house bank and also allows the Xantrex charger/inverter to charge the start battery.

By the way, my Xantrex charger/inverter has an "echo charge" output that is usually connected to the start battery. I haven't gotten around to disconnecting this yet but plan to do so because it is superfluous now that the ACR is installed.

If it is true that you boat has neither the solenoid switch nor an echo charge output from the charger/inverter, then what the surveyor said is probably true. An ACR will solve that problem and is fairly easy and inexpensive to install. I should mention that in the photo of the ACR, the black box in the upper left is the ACR itself and the two fuses below it connect to the start and house banks. The two fuses to the right are to allow a solar controller to charge the house bank (and via the ACR, the start bank, too).

View attachment 222039

View attachment 222040

I agree
Install a Blue Seas ACR. Small job, and it resolves everything

 

[lacoursmarc]

We have two house batteries in parallel that we charge with solar when we are away from the dock. We can be out for weeks and the batteries maintain adequate charge.it's a cheap and simple solution.

 

[marcham]

Start with the owner's manual (posted link to it in your windlass thread). You should have an automatic battery combiner (if previous owner upgraded) that combines the start bank with the house bank once the alternator is providing output or once the inverter/charger is charging the battery.

If wired from the factory, there is a solenoid that will join the start and house battery once the engine is running, but not when the inverter/charger is charging the house battery. The OEM manual also points to an ECHO charger dedicated to the start battery.

Surveyor's aren't electricians, they have limited time on a boat and don't know each and every boat. That and the potential that the previous owner has made modifications usually requires that you spend a day or so with the manual and understanding what you have or hire a marine electrician to complete an electrical audit, provide you with a functional diagram and update the labelling for the wires.

Where are you located? Richmond BC or Richmond VA?

Your start battery should be AGM. It can be switched off when at the dock and it will loose very little charge, as long as you start the engine every 2 months you shouldn't have an issues. We have a small 7 Amp charger on our start battery just for added piece of mind. In fact, if your boat is correctly wired, all batteries can be switched off at the dock and they will keep charging as long as AC power is provided. The bilge pump is normally wired on the battery side of the house battery switch, so it should still function with the house battery in the off position.

Do you have a multimeter? When connected to shore power and the engine and solar all switched off, what is the voltage of the start battery and the voltage of the house battery?

 

[marcham]

An interesting aside is that our panda generator alternator only charges the start batery it shares with the Yanmar, and does not activate the combiner solenoid. With the genset running the 120v batery charger is filling up the house bank.

As expected. Since you have a 120V AC generator, and your AC charger is probably far more advanced than the regulator combined with the small alternator in the generator, it makes sense to use the AC output to power the DC charger. The combiner relay is wired through the Yanmar ignition which is why it doesn't combine when the generator is operating.