Beneteau battery switch

Aug 3, 2014
65
Beneteau 343 San Francisco Bay
I've looked high and low for a Beneteau battery switch. My switches are basically a "T" handle, 1/4 turn On/Off. I have three batteries, one of which is the isolated engine battery, the other two are the two house batteries. When I isolated all batteries from each other (my boat has a three-station charger), I was unable to find a switch like my boat has, and installed a cheap thing, the handle of which broke at first use. If it comes down to it, I'll install a Perco-type switch, but would greatly prefer a Beneteau switch such as installed when boat was constructed. I need a red switch, but would take a black one and paint it, if need be. Does anybody know where I can purchase such switch? Many thanks.
 
Jun 21, 2004
2,533
Beneteau 343 Slidell, LA
Purchased one from Beneteau in August.
Use the link that Ron provided for Beneteau Spare Parts System and enter part number 953583 (red handle). Final cost including 15% discount was $25.70 + 7.00 shipping. Black handle part number is 134819. Be sure to use the online order system to get the discount.
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
You are off on a tangent here. Wire your house batteries together, there is no need to have two sets of house batteries, and you can pull down much more amperage without reaching your 50%Ah limit when you build a larger house battery. Keep your starter battery separate, that is your plan B in case you draw down the House and can’t start the motor.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Gunni, that is what we do when our Bennies have one switch per one battery. Turn 2 switches, you have a 2-battery bank. Or turn another switch and you have three. One battery go bad? turn it off and not have to rewire the battery cables to keep going. . It is the beauty of this system. We don't have TWO house banks, we have two BATTERIES for house use. I don't have a "starter battery". For overnight I turn off one batt, use the other two for house. The "off one" is the morning starter if the other two have crapped out. I rotate which batt I turn off if out more than one night.
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Ron;
Starter battery on one disconnect, house battery on the other disconnect. If you have the room (and apparently he has room for two batteries on his house bank, maybe more) you just need to wire the house battery bank so that it is 12VDC. There is no requirement for each battery to have a separate disconnect, and in fact there are good reasons not to. And that is the way Beneteau intended the DC system to be configured.
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Aug 3, 2014
65
Beneteau 343 San Francisco Bay
Just want to say that it is quite amazing how many different battery and charging setups there are. It seems that most boats have chargers with two outputs, so the owners have one or two house batteries on one charger output and the engine battery on another. The problem with two batteries on a single charger output is this: if one battery is weaker than the other, the charger/maintainer will only "see" the weaker battery status, and charge accordingly, therefore overcharging the stronger battery. Since my charger has a three-output system, that problem is resolved. Another solution to starter-battery fears is to purchase ($75) one of the compact booster/starters. I haven't needed it yet, but it gives significant peace of mind.
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
The problem with two batteries on a single charger output is this: if one battery is weaker than the other, the charger/maintainer will only "see" the weaker battery status, and charge accordingly, therefore overcharging the stronger battery.
The solution is to make sure that your multi-battery bank (house) is made up of all healthy batteries of the same capacity, not to rewire your system to accommodate a particular beat battery or batteries. ...or to devise a way to use your third charging leg off the charger, just because.

The only reason I bring this up because when I was shopping for our current boat there were a few boats where the owner, or his elected jack-leg marine electrician had come up with some genius ‘better way’ that were actually a degradation of the system. The boat we eventually bought had the least number of these FUBARs and included repairs that would not require the services of a cabinetry carpenter. I scoped and priced the cost of putting things right and the owner paid for them twice - once to have the ill-advised work done, and again when I deducted the cost of restoration from the sale price; and had it repaired.

MaineSail has documented some great upgrades to the DC power system that represent true improvements. But if you’re a relatively competent operator who takes the time to study their DC system, the Beneteau OEM system is perfectly fine.
 
Last edited:
Aug 3, 2014
65
Beneteau 343 San Francisco Bay
I agree with you Gunni, and since I thought so much about it and drew endless schematics. I decided to put each of the three batteries on its own circuit, since I could. My rewiring is completely labeled and only takes 15 min. to reverse if need be. This came about because I left the battery switches on during the bottom job, and not knowing that the engine battery cross-feeds the house circuit, came back to all dead batteries, although I've never learned what specifically drew the batteries down (might you comment on that?). A couple of years ago, you, or perhaps someone from Maine Sail, reminded people that their engine batteries are NOT isolated from the house circuit, in Beneteaus at least, making it possible for the engine battery to be drained while the house batteries are getting drained.
As a last comment in case anybody else has been watching the thread, I was 180 off in my statement about one charging circuit charging two batteries; the real problem is that the charger/maintainer would "see" the best battery as being fully charged, and by that, not charge the weaker battery as needed. Like Gunni stated, two equal batteries would prevent (?) that problem, at least until the batteries age somewhat differentially.
 
Apr 7, 2016
184
Beneteau First 305 Seward, Alaska
I think I have the same setup as you as it relates to battery switches. I have a black and 2 red T switches. I moved the neg to an individual bus. Then made one red for the start battery, one red for the house bank. I made the black T handle an always hot for the bulge, my diesel heater, and few other things. Then I’m going covered the black one with red elec tape.

Basically, my start battery post is almost always off unless the motor is running, then when I leave or get on the boat it is just one switch to turn off and on.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
. But if you’re a relatively competent operator who takes the time to study their DC system, the Beneteau OEM system is perfectly fine.
+1 to Gunni on this one. All owners should obtain the manuals for EVERYTHING on their boat. Draw out schematics additions or subtractions as you do them. Memory can be shorter than you think.
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
This came about because I left the battery switches on during the bottom job, and not knowing that the engine battery cross-feeds the house circuit, came back to all dead batteries, although I've never learned what specifically drew the batteries down (might you comment on that?).
Your low battery absorbed the amperage from your stronger battery. This is what happens on a Beneteau DC system if you do not isolate each bank from the other using the battery disconnect switches.

See Stu’s comment (#8) above. It contains a link to MaineSail’s Beneteau DC system and diagram. The first diagram captures everything we are talking about.

The utility of having a mult-battery bank of like-age quality batteries is that they draw down at the same rate and charge at the same rate. And because you now have many more amp hours in the house, you draw the batteries down much less per given discharge, this is healthier for batteries than running them low as you necessarily would in a single battery bank. MaineSail has done some very scholarly work on battery technology, his website has a wealth of information regarding state of charge, battery chemistry, battery discharge, battery charging, and available monitoring systems. https://marinehowto.com/category/electrical/

Start your engine with the house battery. If your house battery is depleted, throw the disconnect to off, turn the starter disconnect to on and start. Remember to reverse that switching once your house has been recharged. Save your start battery for emergencies.
 
Jun 21, 2004
2,533
Beneteau 343 Slidell, LA
JM,
Have to be careful with the 343 circuitry. Initially, there were many reported problems with the batteries discharging.
On 343's equipped with a windlass, Beneteau installed relays to combine the starter & house bank to ensure maximum amperage to operate the windlass. I found out the hard way on a chartered 343 that it can be a problem if not operated correctly. The charter boat had a 4D house bank and separate starter battery. Upon leaving the home base marina, both battery switches were "ON", I turned the starter battery switch to "OFF" and sailed for approximately 5 - 6 hours with the refrigerator, instruments, radios on. When I turned the starter battery switch "ON", the starter battery had discharged to the point that the engine would not start! No combination of switching provided enough amps to start the engine. Not going to go into detail as to what happened next; however, I investigated the matter further and found that unless both the starter and house battery switches are simultaneously switched "OFF" to de-energize the relay, the relay stays on and the batteries remain combined. To de-energize the relay and uncouple the house & starter batteries, both switches need to be turned off simultaneously and then the house bank switch can be turned "ON" without the relay combining the banks. There were several owners who initially had this happen. I think that Beneteau eventually published a revised wiring scheme. On my boat, I removed the relay. I know that I need to turn all the batteries on and run the engine to provide the amps necessary to operate the windlass. Actually, my house bank is big enough to operate the windlass; however, I want to discharge them as little as possible; therefore, I run the engine. So check out your wiring scheme, you may have this relay issue that could cause a problem.
 
Aug 3, 2014
65
Beneteau 343 San Francisco Bay
Thanks to all. Love getting input on these things, and at this point, feel like most of the variations that have been posted, work pretty well for the owners. Like one person said, draw the schematics of the changes, and save them in the boat's owner's manual.
 
Nov 11, 2018
12
Beneteau 45F5 6 Melbourne, Victoria
Just a heads up on the T handle battery switches. I tuned my engine battery off and was surprised to find I was still able to start the engine.
I found the problem was with the switch, if the nut in the handle comes loose then the switch remains closed no matter what possition it's in! At least, in its failure mode, you still have power.