Battery Switch Hookup

[BrianW]

I have a Hunter 26 with a Honda 9.9 outboard (electric start). The Honda has a 12-amp battery charging current. I have a Guest 2100 battery switch which has alternator field disconnect (AFD). I would very much appreciate this group's help in confirming the correct connections. See attached photo of switch.

(1) Switch Bat 1 connection to Battery #1 (+) and Switch Bat 2 connection to Battery #2 (+).

(2) It is my understanding I cannot protect my outboard's alternator with the AFD feature. Is this correct?

(3) Will the 20-amp fuse on the outboard's battery-charging system protect my outboard's alternator if I forget and switch both batteries off while the outboard is running (or start with the motor with the recoil starter)?

(4) Where should I connect the 2 battery cables coming from the outboard?

(5) Where should I connect the solar trickle charger?

(6) Where should I connect the bilge pump?

(7) Does anything in my setup go to switch Feeder or Field connections?

(8) Anything else I should be aware of?

Thanks a million!! BrianW

 

[kenn]

It would help if you could draw out your current wiring.

Do you currently have two batteries? or are you planning to add another battery? The feed terminal is the "output" of the switch, routing the selected battery to your DC panel and/or engine starter circuit.

What does your outboard's manual say about connecting or loading the charger? My 5 hp Suzuki also has a "charging" output (6A) and if your motor's like mine, the charger doesn't care whether it's seeing a battery or not. It's not like an alternator in that regard: it won't blow up in the absence of a battery load. So AFD is probably not useful in your application.

Because of all the uncertainties, you should consider hiring a pro, at least for a couple of hours, to discuss your requirements, inspect your current setup, and design something for you.

 

[BrianW]

Thanks for your reply. I currently have one battery and will be adding a second one. I don't have a wiring diagram, but currently the outboard leads, battery chargers, and bilge pump all run directly to the battery. All other electricals run from a main electrical panel to the battery. The outboard owner's manual does not mention battery chargers or battery switches and has the outboard's wires and boat accessories connected to the battery. BrianW

 

[Johnb]

Probably the outboard does not care whether there is a battery there to be charged or not as Ken has said, but you really need to make sure of that. Maybe call Honda - the question could be phrased as "Could this engine be used on another boat that has no battery"?

The battery selector switch has two inputs, one from each battery and one output to everything you want to power. You can select 1, 2 , both or none. If you connect all sources of charging to the output side then they will charge whatever battery is selected. That can be quite useful if you want to select which battery to replenish at any time.

There are other many more sophisticated ways to do this (and drop $2000 to $3000 in the process) but with 2 batteries and the capability for manual start I would not see the necessity.

About fusing - if you have a fuse at the outboard end of the wire to the battery it will limit the amount of current that could flow from the outboard into the wire, but that is only 12 amps (on a really good day at max output) and not likely do melt wires etc.

Imagine now that the wire gets shorted somewhere in the middle (pinched through, abraded or whatever). Now the battery will be feeding current toward the short at whatever cranking amps it is capable of with comensurate arcing, sparking and melting of fuel tanks or whatever it is near. That is why you need fuses at the battery end.

 

[Barnacle Bill]

The battery switch is designed to toggle between two batteries (1 & 2), or switch to both, or switch to the off position. Usually Battery one goes to one lug and battery number 2 goes to a 2nd lug. The third lug goes to a distribution panel which can operate lights, instruments, motor, etc. The battery charger is not 12v so that would have to be plugged into a 110v AC outlet and then connect it directly to the battery you wish to charge. If you have a battery charger that charges two batteries, then there will be wiring (positive and negative) designed to go to each battery. The outboard does not need 12v to operate, but if you have an electric start, then it needs power to start it. If there is a charging unit (a) in the outboard, or a lighting coil (usually a bridge rectifyer) (b), then you need to have the outboard connected so that the (a) charger will charge your batteries, or the (b) lighting coil will run the lights (but it doesn't charge the battery). Your distribution panel would be a panel with various switches and each switch would include something like interior lights, navigation lights, instruments, bilge pump, etc. You usually want one battery dedicated for engine starting and a 2nd battery dedicated for house purposes, such as lights, bilge pump, etc. But, there might be a time where you want both batteries available to start your engine if you screw up and discharge the starting battery. That is why you have the "both" on the battery switch. So, you can run battery #1 positive to the battery #1 position and battery #2 to thee battery #2 position. From the common you can have two wires heading in two directions. One to the outboard and the other to the distribution panel (or electrical panel). So, when you start the engine, switch it to battery 1 and unless you have charging capabilities or a lighting coil, you can switch it to battery #2 to run lights, instruments, etc.
Actually a bilge pump should be wired so that even if you have the battery switch off, it can operate directly through a float switch which is wired to a positive source so that if you bilge starts filling with water it will operate even if you are not there. Obviously, the negative wires do not run into the switch, but are connected with some sort of buss bar or terminal strip depending on how you wish to wire it. The bilge pump can be fused in line on the positive lead.
Hope this helps clear it up, but if you have questions, ask away.

 

[BrianW]

Got it!
Thanks for the info! BrianW

 

[BrianW]

As Johnb suggested, I called my local Honda dealer and asked if it would hurt the outboard in any way if it was running while NOTconnected to a battery. A service tech said it wouldn't hurt a thing. That confirms the thoughts ya'll shared. Thanks again for your help! BrianW