battery setup on dual ob's

[gooloo]

How is everyone setting up their electrics on dual outboard configs?

I'm looking at setting up the electrics on a dual ob cat.... usual electrics - sounder, radios, lights, bilge pumps, etc.

I figure there's 3 options -

option 1 - 1 battery per engine. either run all accessories to 1 engine (and carry jumper leads), or try and balance the accessories across both batteries (and just pray you dont drain both)

option 2 - 2 batteries on a boat switch (maybe with vsr for ease of use).... start both engines off primary battery and use second battery for accessories

option 3 - 2 batteries on a boat switch (maybe with vsr for ease of use) feeding one engine (one for starting, one for accessories).... second individual battery to start second engine

I'm leaning towards option 3 because it has extra redundancy and the only real sacrifice is the cost of a third battery and the (unbalanced) weight gain.

Very interested to hear how others are setup.... please let me know how yours is configured, what you like about it, what you'd do differently in hindsight, etc

[Chimo]

Hi Gooloo

I have a duel engine setup.

Initially the boat had 2 batteries with one for each motor and all the electronics fed off the one, ie the stbd battery.

After the GPS Sounder lost pixcels due to spikes from when the stbd motor was started I had the unit replaced under warranty and was told by Lowrance if the new unit dies I was on my own unless I isolated the electronics from the starting circuit / batteries.

I now have 2 motor batteries that are only connected to their respective motor BUT can be linked with a connection circuit operated by a key if one or the other motor battery dies for some reason. I have only had to use the switch once ie you start the motor with the crook battery first and get it running nicely then disconnect the other motor's battery and then start the motor with good battery.

On top of all this there is a house battery (deep cycle etc ) which now has all the electronics run off it. This "house" battery is charged off the Stbd motor battery and is connected via an Auto Battery Coupler and this disconnects the motor battery from the house battery and electronics when the motor is started and spikes are possible. No switching no touching, its idiot proof so that when somone new gets into the boat they cannot stuff things up as there is nothing for them to fiddle with.

Had a simple, cheap and dangerous system, what I now have is idiot proof with safety and redundancy and I wont be changing it and any future boat will have the same set up.

The Auto Battery Couplers work a 180 amp relay and are made on the Gold Coast and I dont sell them or fit them but I bought one!

Cheers
Chimo

[gooloo]

thanks Chimo....

that sounds like an advanced version of my option 3.... I'm happy to carry jumper leads in the boat so I can get by without the connection switch between the two starting batteries.

Does the auto battery coupler also control charging / discharging? does it prevent you draining the starting battery with accessories? like a voltage sensing relay? or is it just to isolate the house battery when starting?

[John Buoy]

How is everyone setting up their electrics on dual outboard configs?

I'm looking at setting up the electrics on a dual ob cat.... usual electrics - sounder, radios, lights, bilge pumps, etc.

I figure there's 3 options -

option 1 - 1 battery per engine. either run all accessories to 1 engine (and carry jumper leads), or try and balance the accessories across both batteries (and just pray you dont drain both)

option 2 - 2 batteries on a boat switch (maybe with vsr for ease of use).... start both engines off primary battery and use second battery for accessories

option 3 - 2 batteries on a boat switch (maybe with vsr for ease of use) feeding one engine (one for starting, one for accessories).... second individual battery to start second engine

I'm leaning towards option 3 because it has extra redundancy and the only real sacrifice is the cost of a third battery and the (unbalanced) weight gain.

Very interested to hear how others are setup.... please let me know how yours is configured, what you like about it, what you'd do differently in hindsight, etc

This is how mine is set up quite simple and very efective with all options covered
Can select which battery to run electrics , can isolate everything when not in use,
Can use a jumper assistance in emergency only and all you need is 2 "on/off" battery switches and one "1/2/or Both" switch which i use instead of the
tie switch pictured below and hook up the electrics to common on this switch ;)

http://img20.imageshack.us/img20/915/alternatedualbatterycon.gif (http://img20.imageshack.us/i/alternatedualbatterycon.gif/)

Regards Frank

[Captain Seaweed]

I have battery for each outboard and a third that can parallel to eith batt 1 , batt2 or both. All batteries run isolators.

Marty

[Chimo]

Hi Gooloo

The answer to your question is a definite yes.

Does the auto battery coupler also control charging / discharging? does it prevent you draining the starting battery with accessories? like a voltage sensing relay? or is it just to isolate the house battery when starting?

Usage from the house battery is kept isolated from the motor if the voltage drops below a certain point. So the starting batteries are always OK to start the motor even with allnighters. I fitted LED light globes in my cabin and the side deck lights so usage is lower now too.

When you turn the key to start the motor the voltage drops in the starting battery so the ABC disconnects the house battery (so no spikes from starting can affect electronics) and does not reconnect until the motor battery voltage has increased to the appropriate level.

With the ABC in place I dont have to do anything, its all automatic.
If I want, I can look and see a green light on or not, to tell me batteries are connected by the ABC or not, thats all the info I need, if the mood takes me.

Forgot to mention I also have another couple of keys to switch off the motor batteries and fully isolate them.

Cheers
Chimo

[Ratman]

This link might be of assistance, or do your head in.

Mick

http://continuouswave.com/whaler/reference/dualBattery.html

[Daisy Burnett]

Mate go the dual battery switch hooked up to all. I generally run on both then when I get to the fishing ground switch to either one and leave one fully charged for the return trip. That way if you are there for a while and run a lot of lights etc you allways have start up power.

Cheers
Daisy