Recharging House Battery with Outboards

[Jonah]

I know, I know, I should get a degree in electrical engineering. Maybe Seasick will start an online Masterclass, and I can sign up ...

My house battery was relocated by a previous owner. It now sits under the aft cabin. It powers my DC electronics (helm, cabin, etc.). It does NOT get recharged by either of the two outboards, and I would like to try to fix that. Could anyone send a link, or recommend a book, that would guide me in what's needed?

If it helps, I do still have a wire that runs from my DC panel to the stern. Before finding the relocated/hidden house battery, my electronics were running off of the starboard starter.

 

[suzukidave]

assuming you have shore power also and do not draw down heavily on the house battery, a simple remote charging solution is a dc-dc battery tender installed as an accessory and switched off your ignition circuit. it will use fairly normal size wires to give the house battery a trickle charge whenever the motors are running without requiring any balancing, isolation, or large cables. it's not a fast way to recharge a battery though.

 

[georgemjr]

Yamahas have the ability to run a second charging wire off the engine (at least me HPDIs do). I have the second lead charging my house, located under my center console on my Regulator with an additional start battery for each engine.

 

[Jonah]

assuming you have shore power also and do not draw down heavily on the house battery, a simple remote charging solution is a dc-dc battery tender installed as an accessory and switched off your ignition circuit. it will use fairly normal size wires to give the house battery a trickle charge whenever the motors are running without requiring any balancing, isolation, or large cables. it's not a fast way to recharge a battery though.

Thanks SuzukiDave. Yes, I actually use a Deltran Battery Tender Jr to recharge the house battery. The charger plugs into the AC outlets in the cabin, and runs under the companionway steps to the compartment under the aft cabin. So yes, whenever I'm on shore power, the house is getting recharged and maintained.

But my interest is in long overnight trips without shore power. So this is an interesting idea you've proposed. Not ideal, but may be a good Plan B if wiring the house to the outboards turns out to be over my head.

 

[Jonah]

Yamahas have the ability to run a second charging wire off the engine (at least me HPDIs do). I have the second lead charging my house, located under my center console on my Regulator with an additional start battery for each engine.

Nice, thanks Georgemjr. Mine are 2012 225s, so I will look into this option of recharging a second battery off one (or both?) of the outboards. That would work well.

Do you think I could use my existing wire that runs from the stern to the DC panel, which used to power the DC electronics from one of the starter batteries? Or should this charging wire run from the outboard directly to the house battery, instead of to the DC panel?

 

[seasick]

I have not installed one of these but I am sure several folks on this board have similar products. You can install a battery combiner. It will direct a portion of the main battery's charging current to a second battery if it needs charging (usually determined by it's voltage. These devices are 'intelligent and protect you from having your main run down due to charging of the house battery.
This is one example of such a device, there are others.
https://www.invertersupply.com/inde...4894770497878&utm_content=Product Listing Ads

Thanks for the plug ( pardon the pun) but no master classes on the calenday

 

[Jonah]

I have not installed one of these but I am sure several folks on this board have similar products. You can install a battery combiner. It will direct a portion of the main battery's charging current to a second battery if it needs charging (usually determined by it's voltage. These devices are 'intelligent and protect you from having your main run down due to charging of the house battery.
This is one example of such a device, there are others.
https://www.invertersupply.com/index.php?main_page=product_info&products_id=2602&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping&utm_term=4584894770497878&utm_content=Product Listing Ads

Thanks for the plug ( pardon the pun) but no master classes on the calenday

Thanks Seasick,

This is a nice option to know about too.

By the way, am I the only one trying to charge three batteries with two outboards? How are others on this forum recharging their house batteries? Just with a shore-power charger?

 

[artodea]

If you have the aux charging option on your outboard that is just the ticket for you. Run the aux charging wire from one of your outboards through the rigging tube to your stern and connect that to the house battery with an appropriate in-line fuse.

I think you'd be fine using the wire that runs from the stern to the DC panel - just make sure the wire size is sufficient for the current and length of the run, and include a fuse. Also, make sure you don't have a situation where the house battery can be isolated from the DC panel (e.g., a battery switch turned off). Not sure what would happen to your electronics if you run the engine and electronics without the house battery on line.

 

[Jonah]

If you have the aux charging option on your outboard that is just the ticket for you. Run the aux charging wire from one of your outboards through the rigging tube to your stern and connect that to the house battery with an appropriate in-line fuse.

I think you'd be fine using the wire that runs from the stern to the DC panel - just make sure the wire size is sufficient for the current and length of the run, and include a fuse. Also, make sure you don't have a situation where the house battery can be isolated from the DC panel (e.g., a battery switch turned off). Not sure what would happen to your electronics if you run the engine and electronics without the house battery on line.

Thanks Artodea,

Sounds like I need to find out whether my outboards offer this feature. I should think they would, since it would be reasonable to imagine one of these outboards being used on a single-engine, dual-battery boat.

 

[suzukidave]

Thanks SuzukiDave. Yes, I actually use a Deltran Battery Tender Jr to recharge the house battery. The charger plugs into the AC outlets in the cabin, and runs under the companionway steps to the compartment under the aft cabin. So yes, whenever I'm on shore power, the house is getting recharged and maintained.

But my interest is in long overnight trips without shore power. So this is an interesting idea you've proposed. Not ideal, but may be a good Plan B if wiring the house to the outboards turns out to be over my head.

this is an example of what i mean. a 2 amp trickle charger like your deltran only it runs on dc and only needs 2.7 amps (plus the voltage drop). it gives gives complete isolation and is fairly simple to rig. you could comfortably use 10 gauge wire (or maybe even 12 gauge) to wire it 20 feet from the motor.

https://optimate1.com/product/optimate-dc-to-dc-2/?v=3e8d115eb4b3

the dc-dc chargers are used in rvs and by the offroad crowd to charge batteries in trailers. the main advantage is that you only have to run wires sufficient to handle a small ampage draw that the main batteries should never notice.

the issue with using a standard isolator/management system, with a battery up forward, is you shell out hundreds in lengthy full size battery cables and connections to be able to send 20 amps forward that you may never really need to send. easier to move the house battery to the rear than do that.

 

[suzukidave]

I have not installed one of these but I am sure several folks on this board have similar products. You can install a battery combiner. It will direct a portion of the main battery's charging current to a second battery if it needs charging (usually determined by it's voltage. These devices are 'intelligent and protect you from having your main run down due to charging of the house battery.
This is one example of such a device, there are others.
https://www.invertersupply.com/index.php?main_page=product_info&products_id=2602&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping&utm_term=4584894770497878&utm_content=Product Listing Ads

Thanks for the plug ( pardon the pun) but no master classes on the calenday

i like that thing.

 

[suzukidave]

Also, make sure you don't have a situation where the house battery can be isolated from the DC panel (e.g., a battery switch turned off). Not sure what would happen to your electronics if you run the engine and electronics without the house battery on line.

this is an excellent point. you need to map your current system and understand it. i assume the engine electrical system is completely and permanently separate from the house battery electrical system and everything in the boat sees one or the other. if you have the option of letting the house circuit "see" the engine circuit that needs to be disabled or else factored into the design if you intend to use an isolator system to charge the house battery using the main batteries.

the only exception to this would be relays. you can have a good quality relay that uses engine ignition power to switch all or part of the house system on or off.

 

[georgemjr]

I would recommend speaking with Andy at SIMS (shipyard island marine. He would know and would supply you with the part.) Similar question on the hull truth:

https://www.thehulltruth.com/sim-yamaha-verado-club-parts/493682-aux-charging-lead.html

This is either the part or a similar one for a different engine:

https://www.simyamaha.com/Yamaha_Isolator_Lead_p/mar-69jis-0l-ed.htm

A picture of where it connects on a yamaha:

 

[SkunkBoat]

Hey Jonah, I've been hesitating to chime in here because without clearly knowing what you have there, its impossible to give specific advice.
So here are some considerations.

Are both the starting batteries connected with two standard battery switches(1/both/2/off) as they were from Grady?
Are the starting batteries NOT connected in any way to the HOUSE except the ground.(This would mean nothing on your boat ever has power if you disconnect the HOUSE battery, even when motors running)
The switches cannot in any combination cause you to draw STARTING power from your HOUSE?
What gauge wires, if any, connect the House to the Starting batteries. On the Negative only?

Because your HOUSE is separated from the starting batteries and Motors by some distance, you would need very large wire and a FUSE if you were to start motors with the HOUSE.

So, assuming you have wired it so that is not possible, it is possible to use the Aux charging from both Yamahas to charge the HOUSE.
You could also use a VSR from each starting battery + to your HOUSE + ..... I'm only guessing you could get away with 10 gauge wire.


******THESE ARE BothON/BothOFF/COMBINE switches not the standard 1/both/2/off switches!!!!!***
You would only need one switch for the motors (IMAGINE THAT THE RIGHT SWITCH IS NOT THERE)
basically, you can do what is pictured here EXCEPT the HOUSE cannot connect to the right battery switch. It must only go to the house panel(thru its own on/off switch or 40 amp Breaker switch)

Of course, its not pictured but all the negatives are tied together with 8 or 6 gauge wire.

 

[Jonah]

this is an excellent point. you need to map your current system and understand it. i assume the engine electrical system is completely and permanently separate from the house battery electrical system and everything in the boat sees one or the other. if you have the option of letting the house circuit "see" the engine circuit that needs to be disabled or else factored into the design if you intend to use an isolator system to charge the house battery using the main batteries.

the only exception to this would be relays. you can have a good quality relay that uses engine ignition power to switch all or part of the house system on or off.

SuzukiDave, thanks for all these replies. I have some homework to do, and then will report back.

 

[Jonah]

I would recommend speaking with Andy at SIMS (shipyard island marine. He would know and would supply you with the part.) Similar question on the hull truth:

https://www.thehulltruth.com/sim-yamaha-verado-club-parts/493682-aux-charging-lead.html

This is either the part or a similar one for a different engine:

https://www.simyamaha.com/Yamaha_Isolator_Lead_p/mar-69jis-0l-ed.htm

A picture of where it connects on a yamaha:

Nice, thanks GeorgeMjr. Will refer back to this as I do some homework this weekend.

 

[Jonah]

Hey Jonah, I've been hesitating to chime in here because without clearly knowing what you have there, its impossible to give specific advice.
So here are some considerations.

Are both the starting batteries connected with two standard battery switches(1/both/2/off) as they were from Grady?
Are the starting batteries NOT connected in any way to the HOUSE except the ground.(This would mean nothing on your boat ever has power if you disconnect the HOUSE battery, even when motors running)
The switches cannot in any combination cause you to draw STARTING power from your HOUSE?
What gauge wires, if any, connect the House to the Starting batteries. On the Negative only?

Because your HOUSE is separated from the starting batteries and Motors by some distance, you would need very large wire and a FUSE if you were to start motors with the HOUSE.

So, assuming you have wired it so that is not possible, it is possible to use the Aux charging from both Yamahas to charge the HOUSE.
You could also use a VSR from each starting battery + to your HOUSE + ..... I'm only guessing you could get away with 10 gauge wire.


******THESE ARE BothON/BothOFF/COMBINE switches not the standard 1/both/2/off switches!!!!!***
You would only need one switch for the motors (IMAGINE THAT THE RIGHT SWITCH IS NOT THERE)
basically, you can do what is pictured here EXCEPT the HOUSE cannot connect to the right battery switch. It must only go to the house panel(thru its own on/off switch or 40 amp Breaker switch)

Of course, its not pictured but all the negatives are tied together with 8 or 6 gauge wire.

SkunkBoat,

Thanks very much. This is even more specific than I thought anyone would offer. Some in-line replies:

Are both the starting batteries connected with two standard battery switches(1/both/2/off) as they were from Grady?

Yes.

Are the starting batteries NOT connected in any way to the HOUSE except the ground.(This would mean nothing on your boat ever has power if you disconnect the HOUSE battery, even when motors running).

That's right. Except, I do have the option of re-attaching the previous owner's wire that runs from the DC switch panel to the starboard starter, but currently that's unattached.

The switches cannot in any combination cause you to draw STARTING power from your HOUSE?

That's right.

What gauge wires, if any, connect the House to the Starting batteries. On the Negative only?

Off-hand, I don't know what gauge, but yes, it would be negative only.

Because your HOUSE is separated from the starting batteries and Motors by some distance, you would need very large wire and a FUSE if you were to start motors with the HOUSE.

Thanks, but I don't want to start the outboards with the house battery. (If I were in an emergency, I do have jumper cables that can stretch from the house to the starters.). I just want to be able to re-charge the house battery while my outboards are running, just like the starters get re-charged while the outboards are running.

So, assuming you have wired it so that is not possible, it is possible to use the Aux charging from both Yamahas to charge the HOUSE.

Thanks. I think this is what I want.

You could also use a VSR from each starting battery + to your HOUSE + ..... I'm only guessing you could get away with 10 gauge wire.

Ok, I will remember this as a Plan B.

Thanks again; I will try to digest this super-helpful image over the weekend.

———

p.s. Does everyone else re-charge their house batteries with their outboards? I figured it was pretty standard, but I'm starting to think that maybe I'm trying to do something extravagant/unnecessary?

 

[SkunkBoat]

[QUOTE="Jonah, post: 162226, member: 20174"
p.s. Does everyone else re-charge their house batteries with their outboards? I figured it was pretty standard, but I'm starting to think that maybe I'm trying to do something extravagant/unnecessary?[/QUOTE]

YES...pretty much EVERYONE charges the house with the motors.

 

[Sdfish]

In my whaler I used a BlueSeas ACR to combine both batteries when using the outboard to charge.
I plan on adding an ACR to my Grady shortly. Both my batteries are right next to each other in the stern, so the install is easier.
As Sunkboat pointed out, your set up may be a little more complicated and would require appropriately sized wire and fusing.

Good info on the BlueSeas site, they also have great tech support you can call to answer specific questions. ( I will use this product on my Grady)

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

 

[SkunkBoat]

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