Beneteau 423 battery question

Dec 4, 2019
25
Beneteau 423 Jacksonville
We are the proud new owners of a 2004 423 and are getting it in shape for some fun sailing. I am trying to figure out the battery selection options. When I select the #1 battery, I am selecting the start 12 volt battery, and when I select #2, the house bank or 2 4D batteries. If the start battery fails, can the house bank be used to start the engine? I turned off the start battery and left the house bank on, but I couldn't start the engine. Also, if I turn off the house bank, the start battery still powers the house circuits.
Is there a good wiring diagram I can access that is a bit more detailed than the owners manual schematic?
Jeff
 

NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
Congranulation! I am a new owner of a 2005 423 by 3 years..... we love the boat.
There is a schematic in the owners manual that will help. Also Maine sail has a diagram along with his fix.
If you look behind the aft section where the switches are you might see a jumper cable going from post 1 to post 2...... so when one is on it serves for the others duties. And when both are on they will be equally depleted. Causes issues for many people that do t realize this then find themselves with a dead starting battery after a weekend on the hook.
But regarding the jumper cable, some boats do t have them. Also it seems strange that house does not start boat however start bank powers entire boat.
When I first bought our boat the wiring made my head spin..... after three years of doing upgrades I am getting a better understanding.... though I still am not a fan of the wire
Panels beneteau uses.

Good luck! Great boat.....

Greg
#209
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
On our boat, unaltered from the factory, the house battery bank will NOT start the engine. I have a small jumper battery pack that I carry, and have tested to make sure that it will start the engine if my start battery is drained. I also carry a set of jumper cables, just in case my little battery is not up to the task if I need it.
 
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Likes: Dave c30
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
... Is there a good wiring diagram I can access that is a bit more detailed than the owners manual schematic?
How much more deail do you expect? It is questions like this that make me wonder if people have the owners manual for their boat. And for the Engine. On the SBO home page there is a list down the left side. Select boat info, then your 423 model to get the owners manual you can download. I made one copy i put in page protectors and keep that at home for ready reference. A second copy, I have on the boat and make any changes to that copy. The home copy stays OEM, as new.

Edit: I looked back at the 423 manual. My 323 came with 2 batts, house and engine. I added a 3rd batt and just labeled them as #1,2,3,. On the 423 schematic, I think some guys are saying their boat does not have the jumper between the house and battery load sides, but some do? I consider that jumper the positive buss , though I beefed mine up in size because it could now be carrying double the amperage of just the 2 batts.
 
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NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
Well “jeffinjax” feel free to ask me any question you might have...... I know what it’s like to roll over at 2am (or any time for that matter) with a boat question in my head and no manuals at my fingertips...

Greg
s/v Souleil
 
Dec 4, 2019
25
Beneteau 423 Jacksonville
Greg, Ron, and Dave,
Thanks for the answers and comments. I’ve looked at the owner’s manual online and own one as well. The electrical diagram there looks like the house can start the motor. But clearly from your input, and my experience, it doesn’t. Good enough. I, too have the jumper between the start and house batteries. It’s good to know there is a forum with knowledgeable owners.
Jeff
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Greg, Ron, and Dave,
Thanks for the answers and comments. I’ve looked at the owner’s manual online and own one as well. The electrical diagram there looks like the house can start the motor. But clearly from your input, and my experience, it doesn’t. Good enough. I, too have the jumper between the start and house batteries. It’s good to know there is a forum with knowledgeable owners.
Jeff
I don't suppose the one battery is dead???
 
Feb 12, 2018
1
Beneteau Oceanis 423 Seattle, WA
Hi there! There is also a Beneteau 423 Owners Group on Facebook that is quite helpful!
 
Dec 4, 2019
25
Beneteau 423 Jacksonville
Thanks for that information. I’ll look it up.
Ron: both battery show 12+ volts on the battery tester and a digital multitester. I’ll have to dig into this a little more.
Thanks
 

NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
trace the starter wire back to the switch and see how it connects as if you have the jumper the house should start the engine..... unless the jumper is on the wrong side of the #1 switch which may be the case here (now my #1 solution to this situation). As I said I have the jumper and know many that do also and the house will start the engine when 1 is off.

dumb question but when you are turning off 1 (starter) you do leave the black switch on as this isolates all neg? And also maybe check the connections including your grounds. My main ground to engine looked good but when I took everything off the bolt, there was significant corrosion causing issues when I first got boat (I ended up adding a neg bus bar as the original connection has too many wires in my opinion).

This appears to be a wiring / battery issue not really specific to the 423.

Keep digging.......... it will be obvious once you trace wires. Any questions feel free to ask!

Good luck
Greg
 
Jul 20, 2019
9
Beneteau 423 Rock Hall
We also are on our 3rd year 2007 423. Our house bank will start the engine. Start battery will not power house. I think Greg is on the right track. Maybe a jumper on wrong terminal? Jim
 

NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
It might not be the "wrong" terminal. Just another way to connect them to achieve different ends. My start will run the house and my house will start the boat...
 
Dec 4, 2019
25
Beneteau 423 Jacksonville
Haven’t been to the boat this week yet, but I’ll check the wiring. I looked earlier and it appeared there was a connection between start and house banks, as the wiring diagram shows. It’s a 4/0 (I think) really big wire that originates at the starter, and goes to the start battery switch first, then there’s a jumper or connection equally large, if short, to the house switch. I’ll take a picture. I puzzled through the wiring schematic in the owners manual and can’t see that there is a dedicated, start battery only circuit to the key switch.
 

NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
Start battery on mine is under aft berth behind the shaft compartment.
 
Dec 4, 2019
25
Beneteau 423 Jacksonville
Likewise for the start battery. My house bank is an aged pair of 4Ds under the companionway stairs. We can’t discern a date on them, but they just feel old.
We have been busy with running rigging replacement and other topside chores, as well as the unenviable tasks of rebuilding the macerated pumps and switching the forward head holding tank hoses so the macerater pump would pump overboard. The hoses were switched so the head flushed to the bottom of the tank and the pump out was at the top. Much better now.
Ah, that wasn’t a good description, but the hoses were switched, probably from birth.
 

NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
I just got rid of my 2 4D's and added 4 Trojan T125 6V. So much nicer. With holding tanks, I removed the macerator pump (front head) and switched front head to a gravity discharge and eliminated one of the thu hull fittings. More room, less crap to break. Doing aft head this winter....



.
 
Dec 4, 2019
25
Beneteau 423 Jacksonville
We thought about converting to gravity dump. It makes sense to remove extra plumbing and thru hulls. That’s on the list...
I’m still looking at battery options.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
If your vessel is wired like many Bene's & Jenneau's, you may not have "HOUSE" and "START". What many have is two battery banks that are in parallel when both switches are set to ON. Leave both switches set to ON, discharge too far, and you're dead in the water. We've a number of Bene & Jenneau customers who've learned this lesson the hard way.

Unfortunately many, but not all Beneteau's, have a bussed switch system where by HOUSE and START switches are permanently bused (hard wired) together on the load side of the switches. Any time both red switches are turned ON both battery banks are in parallel. Many owners are unaware of this wiring scenario and incorrectly assume they have "isolated" HOUSE & START banks.. If your boat has this wiring it is best to correct this issue. I have even heard of some owners and delivering dealers removing this jumper but not addressing it any further with regard to charging both banks..

If you decide to pull the jumper, you'll need to make sure house loads stay on the house switch and the engine remains with the start switch. You can then re-purpose the negative switch for an emergency parallel.

Below is what this wiring typically looks like. The issues are listed on the drawing, if your boat has this wiring scenario. Link to full size image if needed: http://www.pbase.com/mainecruising/i...1/original.jpg


The diagram below (drawn for a customer) corrects for the Beneteau bused switch system and adds alternator to house bank wiring plus an emergency parallel (the old negative switch), dedicated & isolated start and house banks, full isolation of each bank and full cross over and an ACR for automatically charging both banks.

 
Dec 4, 2019
25
Beneteau 423 Jacksonville
Wow. What great information! I think we are in the "parallel battery" situation on our boat, too. But what is baffling is why we can't start the motor on the house when the start battery is turned off. More research is indicated. Bad/corroded grounds?
Thanks, all for your posts and information. Stay tuned as we take a deep dive into the wiring.