Kevlacat 5.2 connecting both batteries

[fromeo]

Hi Guys ,
As part of my ongoing repower and refurb of my 5.2 I would like to connect my 2 batteries on my 5.2 together with an on / off switch as some of the factory 5.2 's were fitted, would somebody be able to check there wiring out and let me know how they are connected so can get it right ...Thanks in advance

[cormorant]

Dumb question - why do you want them connected. A third house battery for all accessories off a VSR is a safer option if you have the space and that way motors are independent as you would never run it with switch on both anyway. The correct tinned battery wire and lugs are probably more expensive than a new spare battery and shorter leads.

My other suggestion is jumperleads are cheap.

[finding_time]

Fromeo

I'm struggling with Cormorant opinion on this one! Mate mine are linked( factory fitted) on one side( Starboard) i have 2 switches. One for that battery and one to isolate the conection between the two. The other side (Port) just has one switch for that battery and i run this one as the house battery! I use the starboard side to start the engines and when running i keep both on then when i stop i isolate this battery ( starboard) and just run the ports for lights,etc. If one battery fails i can use the link to start the other sides engine;)

Send me a diagram and i'll check it against mine! Forget the idea of a third battery why carry the extra Kg's?

[Mister]

Twin engines, one battery per engine, one additional switch it is all very simple and straight forward.

Being able to selectively connect both batteries to one engine or one battery to both engine or one battery/engine to the other battery/engine gives all the flexibility required without the need for an additional battery or VSR.

All the third switch does is connect the combinations (using other switches) in times of need and normally not required. You should run/start each engine from normally connected battery and only connect them if things fail. All this starting and switching from one battery should be avoided and besides is not necessary.

If you do over night trips then what does need to be done (needs to be done anyway) is to configure your essential operational wiring so that you can totally switch one battery out if required.

The third switch should only ever be a backup for those times things have gone wrong.

All the third switch does is links the battery positives with the negative connected directly between the battery terminals.

[cormorant]

Fromeo

I'm struggling with Cormorant opinion on this one! Mate mine are linked( factory fitted) on one side( Starboard) i have 2 switches. One for that battery and one to isolate the conection between the two. The other side (Port) just has one switch for that battery and i run this one as the house battery! I use the starboard side to start the engines and when running i keep both on then when i stop i isolate this battery ( starboard) and just run the ports for lights,etc. If one battery fails i can use the link to start the other sides engine;)

Send me a diagram and i'll check it against mine! Forget the idea of a third battery why carry the extra Kg's?

So both motors start off one battery but charge each battery seperately??

If a battery was to fail ( I mean collapse a plate) then you could well end up with no battery power as it can short other one? 2 alternators charging one start battery or boath batteries acting as one big battery? The dead battery can well kill both alternators / voltage reg /rectifiers dead.

I know a 3rd battery is heavy and not required but I see so many twins set up with systems that are not totally independent under normal running and people are slack with switches and leave them on both all the time.

Not well written by me but run all access off one battery ( larger possibly glass mat) connected to one motor. Other motor to other battery. Jumper leads if you ever have a battery failure or run it down too much.

Ever having batteries on both is a very risky especially as guage on dash will only show alternator output .

Some motors have a accessory for dual battery charging but check how it works.

[John Buoy]

I find this connection very versatile
It gives you the option of isolating your engines
It gives you the option of running the House battery from either B1 or B2
And also gives you the option of emergency jump start from B1 to B2.

The only difference i have on my set up is that i hard wired
a connector/plug to each battery so when i get home from fishin/boating
i simply plug in the Ctek Smart Chargers to each battery and let it trickle away keeping the batteries in optimal condition before each use.

For those who find it difficult to read this is basically your 3way switch
in the middle and 1 on/off switch per motor.

http://img213.imageshack.us/img213/7946/twinbatteryjj6.jpg (http://imageshack.us)

Here is a link also to how the yanks do things on their Boston Whalers
http://continuouswave.com/whaler/reference/dualBattery.html

Regards Frank

[fromeo]

Thanks for your input so far guys just a bit more clarity , using Franks Diagram, does this mean that a cable connecting -neg to -neg on the motors needs to be run as well as the -neg to -neg on the batteries or will the one -neg to -neg on the batteries be enough ? see my current set up attached

[John Buoy]

you need to run each motors -neg to a battery and run a Neg cable
from Battery to Battery and all will be fine.

Frank