Dual battery set up

Hi just wondering if anyone can help me with my dual bettery set up.

 

I had just one battery hooked up, it was charged and worked fine. Then I decided to get another battery and make a dual battery set up. One was a bit flat so I started off the second, after running all day with the switch set to BOTH the battery was still dead flat. I charged it up before I went out the next time, left it on both, and it drained completely leaving only battery number 2 charged. The only thing I can think is how I earthed the first battery.

Can anyone shed some light on this?

 

The Red is the positve + lead, Grey is negative -

 



 


TAPOUT's picture

Posts: 885

Date Joined: 27/01/06

 It sounds like battery 1 may

Thu, 2012-05-10 20:30

 It sounds like battery 1 may need replacing. It may have dropped a couple of cells which means it will charge up but once under load it will drain very quickly. Try load testing it.

just dhu it's picture

Posts: 1081

Date Joined: 14/05/09

check battery

Thu, 2012-05-10 20:37

i agree with tapout , sounds like the battery is failing , take it to a battery place and get it load tested

fishy fingers's picture

Posts: 1719

Date Joined: 28/04/07

Use a vsr

Thu, 2012-05-10 20:42

once you check your batteries install a VSR (Voltage switching relay) made by BRP it will automatically switch to the battery needing charge without you having to switch after starting therefore keeping both charged but you can switch to one or the other if you need to

flexn's picture

Posts: 232

Date Joined: 19/03/12

where do I get one of these

Thu, 2012-05-10 20:43

where do I get one of these and what do they usually cost?

 

flexn's picture

Posts: 232

Date Joined: 19/03/12

So is it okay to have it

Thu, 2012-05-10 20:42

So is it okay to have it earthed the way I do though? Battery 2 negative runs to battery 1 terminal. Then another cable goes from battery 1 to the motor. I want to get a new allrounder battery anyways but want to make sure the way I have it set up is ok.

fishy fingers's picture

Posts: 1719

Date Joined: 28/04/07

yes the earth is fine

Thu, 2012-05-10 20:50

you can get a VSR from most chandlers but I got mine from bias on stirling highway

sorry It's a voltage sensing relay not switching!

and it's made by BEP not BRP

about $120

Paul Jackson's picture

Posts: 106

Date Joined: 19/04/09

Three years ago I replaced

Thu, 2012-05-10 20:50

Three years ago I replaced both batteries on my boat and took the advise of the battery specialist, who said that the best thing to do was rig up a trickle charger/battery maintance charger and always leave it connected when not using the boat - similiar to what caravaners do.

To date I have always gone out with fully charged batteries and had no issues at all

I would reccomend this setup to anyone - also use proper "Heavy duty marine Battery's"

PS mine are wired exactly as yours

Cheers

Paul J

flexn's picture

Posts: 232

Date Joined: 19/03/12

I wonder if something like

Thu, 2012-05-10 20:59

Yeah I think I will definately look at that. I wonder if something like this would work

http://www.biasboating.com.au/product_p/3220.htm

Paul Jackson's picture

Posts: 106

Date Joined: 19/04/09

Not sure where you are

Thu, 2012-05-10 22:43

Not sure where you are located - but try your local battery world

 

I use the one in Midland and they know exactly what they are taking about.

 

Cheers

 

Paul J

Posts: 812

Date Joined: 09/10/06

Have always been told never

Thu, 2012-05-10 22:37

Have always been told never to run the switch on both batterys. go out on one back in on the other.

strike_zone's picture

Posts: 403

Date Joined: 09/09/10

never run on both

Fri, 2012-05-11 02:34

sounds like you need a load test on batt 1 it may be stuffed but as said above never set your switch to both unless its an emergency and niether batt will crank your motor over on there own your outboard charging system is not powerful enough to do both batts at the same time with the exception of the latest big motors

spinksy's picture

Posts: 266

Date Joined: 06/10/10

Been told

Fri, 2012-05-11 08:04

Start up on cranking battery, Swich to both when underway,go to 1 to run accessories, back to 2 to start up again.

Posts: 5798

Date Joined: 18/01/12

as said above, NEVER run on

Fri, 2012-05-11 08:54

as said above, NEVER run on both batteries, not because the alternator isnt big enough (it'll still charge just slower) but as you've found if one is knackered and your on both it will probably suck the other dry as well.

Only ever on both to start if necessary or maybe if you have a electric anchor winch.

Ive seen it more than a couple of times over my years at sea having to pass batteries over the gunnel to boats at sea to get started or using the generator batteries to start main engine.

Trickle chargers are a good thing as well EXCEPT that its possible to mask a problem-ie a battery is on the way out after sitting in the driveway and trickling keeps it up, get in the water anchor up for a few hours then it wont start.

 

If you cant pull star your outboard-dual batterys for sure!

Incidentally for a laugh a mate and I tried to pull start my 115 yam, couldnt do it. Maybe though, as with the "terrified man/bucket" syndrome it'll work the same with a "pull start/drifting into the breakers" syndrome

____________________________________________________________________________

 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.