Battery setup options

 I know this has been done several times- the search function does work...

However-

 

Current setup 2 bats with isolator- all electrics are wired to it so if you select 1 and drain it flat then flick to 2 as a back up. or link them. 

I am curious is this a standard with small trailer boats? or do they more tend to run the electronics off the 2nd battery.

The reason I ask is i am worried im getting interferance from the alternator/ engine on the finder etc ( easy fix by running either a third battery and installing solar as well  or running a set of wires from battery 2)

 Am i being too pedantic and just leave it be or is this a bodgy quick setup and should be changed? 

 

Thoughts and recommendations?


Vinesh87's picture

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 Thats pretty standard for

Sun, 2016-10-09 14:54

 Thats pretty standard for small boats. What inference are you getting?

 

I started going down the path of a 3rd battery but just ended up with smarter battery management. 

 

Ended up with a ctek 250 with smartpass and solar regulator with a 1200cca starting battery and 300amps worth of smaller batteries as the house batteries althrough start and house are linked until the the battery drops below 12.7v.

 

Note i run 2 fridges and a feeezer and all electronics of this system has been very good!

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 i thought the ctek was a

Sun, 2016-10-09 16:57

 i thought the ctek was a solar regulator as well? unless your pumping in more the the ctek can handle.....

Vinesh87's picture

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Yes the 250s has a inbuilt

Sun, 2016-10-09 18:19

Yes the 250s has a inbuilt reg but you know what i mean

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 Interferance appears to be

Sun, 2016-10-09 15:03

 Interferance appears to be static on screens ( could be several other issues but i think it may be alternator whine as it cranks up hard with the motor revs ) pretty food at trolling speeds but past that it gets shitty really quickly- any fix will require a bit of rewire work, hence my question is this normal or should i dedicate my electrics to run off a dedicated battery- ie has anyone done this and got marked improvments or am i chasing my tail...

 

(of note is Everything is running off the same common circuit- 2 fishfinders, radios, winch, radar etc etc. if you activate the winch the cb better have the volume down... and if the battery is on the way out start up will often reset the fish finders)

 

sstevee's picture

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Hey mateWhen I initially only

Sun, 2016-10-09 18:31

Hey mate

When I initially only had a single battery I did get noise through the 27mhz radio when tilting the motor but never had interference on the sounder. I now run two batterys with a voltage sensitive relay which keeps the motor battery charged and connects the two when the motor is running. However I'd be looking at your wiring, specifically for corrosion as I dont think you should be getting that type if interference. Don't rule out your isolator either, if its not a decent quality one they can get green corrosion on the contacts so when you turn it to 'on' you get a dirty connection.

Jackfrost80's picture

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 +1 for the VSR. I had a BEP

Mon, 2016-10-10 15:02

 +1 for the VSR. I had a BEP one installed with my BEP isolator so that I can chose which one is the cranking battery. Was either too lazy or forgettful to swtich the battery over when I got the the spots and usually ran off the one battery all day which would eventually wreck it.

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ranmar850's picture

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You would be better having them isolated.

Sun, 2016-10-09 18:35

 If you have two batteries without a smart relay, with a battery isolato,r you are doing one of two things. if you are running them in parallel, ( Both)you risk having one die and take the other with it. You won't have the second one as the backup you hope for. The other way, not running them in parallel, and running your electronics off that one means that the second one won't be getting charged while the motor is running so you probably also won't have the use of a second battery if you need it for starting.

The best way to manage it is with a smart relay. There are marine ones available off ebay ( Narva) for about $45. Connect it across the positives of the two batteries and the second battery will charge only when the first battery reaches about 12.4 volts. Meaning that when the engine is not running,  anything connected to your second ( house) battery cannot drain your primary ( starting) battery. 

To take it to the ideal level, you need a battery changeover switch, which it sounds like you already have. So connect the smart relay across the terminals of battery 1 &2, and run your normal configuration as Battery 1  ( assuming Start battery is Batt 1). Have all your electronics connected to a supply fed off Battery 2.  If you feel you need both for starting, switch to Both. You shouldn't leave it on Both, as anything that goes wrong will flatten both of them.

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I have a similar issue

Sun, 2016-10-09 18:46

 I have a similar issue with my boat which is old and has old electronics.  Each time I started the motor (an inboard), the voltage drop was enough to cause the Lowrance sounder/GPS combo to re-start.  I overcame it by installing a simple two way switch that separetes the electrics from the start battery.  I have the standard manual battery isolator (1, 2 or both) and I can manually choose battery 1 or 2 to start the motor.  I swap between battery 1 and 2 a couple of times each trip out so that both batteries get charged.  If using battery 1 to run the motor, I flick the switch so that the electrics are running off battery 2 and vice versa.  Its basic but it works. 

Stevo81's picture

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What boat?Are you saying your

Sun, 2016-10-09 19:13

What boat?

Are you saying your electronics are all wired to your switch and you choose which battery bank (1or2) your electronics draw off??

With a BASIC dual battery setup: outboard alternator connected to common of switch, Terminal 1 to + battery bank 1 (starting) Terminal 2 to + battery bank 2 (House)

Battery 1 is purely for starting the outboard. Also wire any auto bilge pumps directoy to this battery and in your case i would connect winch to this battery as you should only be operating winch with outboard running anyway.

You should have all your loads connected directly to "house" battery 2 (obviously can be via fuse panel).

Then, if you want you can flatten your house bank listening to the stereo etc and still have a near fully charged starting battery for your outbaord. 

Add a VSR to the setup and when you start your outbaord it will connect the two banks and charge both while runnning and seperate them when you turn outboard off. 

As for your interference i would get your wiring sorted out properly and then see if you still have a problem but it definately doesnt sound right to me.

 

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 Can i ask why you run auto

Sun, 2016-10-09 19:40

 Can i ask why you run auto bilge pumps off your cranking battery?  I understand the winch bit (as i plan to do that next year when i install one, but i am intrigued as to why you run an auto bilge from a cranking battery and not a deep cycle house battery.

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Stevo81's picture

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My mistake

Sun, 2016-10-09 20:36

 Sorry Randall, typo...meant to write auto bilge pumps wired directly to house battery. Posting off phone 

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Mon, 2016-10-10 09:59

 

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 I have 2 batteries only, but

Sun, 2016-10-09 19:28

 I have 2 batteries only, but use a 3rd switch for house needs.
So you can draw of either battery, charge either or both and link them by putting on both.

Can also run both outboards into the one AGM battery if its low to charge up quicker

Survived many island trips...

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

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Date Joined: 30/11/14

 thanks for the responces, my

Mon, 2016-10-10 20:04

 thanks for the responces, my setup has everything off the one battery or if you flick the isolator it is everything off the second ( or linked if thats what you select) 

i get all the comments - in essence i have no house battery - when folks are throwing this around are you running sounders etc off your house battery? as this would probably mean you are not going to get any interferance unless you link them. 

good points about the corrosion though , i did note there was a bit on the terminals that i cleaned off but havnt had a good look at the isolator.

 

 

 

Jackfrost80's picture

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A VSR automatically switched

Tue, 2016-10-11 09:10

A VSR automatically switched from your cranking battery to your house battery once it drops below a certain voltage. It also charges your cranking battery when you're driving until charged and then automatically switches over and charges your house battery. 

When I had just the isolator switch I was told to crank the outboard with one battery, switch it to both while driving and switch it to the second once you stop and start fishing.

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Common misconception

Tue, 2016-10-11 13:42

 Not quite, small point but it switches when the start battery RAISES to a certain voltage like 13.8 or so.

Also, what you were told is actually a common problem.

The ONLY time you should be on "both" is when you cant start cos there isnt enough charge.
If the reason there isnt enough charge is because a cell has collapsed, trying to charge on "both" may see you with 2 flat batteries.

A collapsed cell can easily draw ALL the current you outboard can produced plus from the other, hence why they get hot.

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 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.

 

Jackfrost80's picture

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 I thought it did that while

Tue, 2016-10-11 14:18

 I thought it did that while charging but switches over to the house battery when below a certain voltage when not charging?

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Opposite

Tue, 2016-10-11 14:29

Yes sorry, it isolates the house when not charging, doesnt switch over but it switches off the link (disconnects).
Starts charging the start battery til it gets to a certain charge level, easiest measured by voltage (13.8 or so) then clicks shut and parallels the house battery with start battery which takes most of the charge as it has a lower resistance

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 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.

 

Posts: 33

Date Joined: 30/11/14

 I guess the options inuave

Wed, 2016-10-12 19:51
  •  I guess the options i have are
  • 1 leave it as is
  • 2 put in a vsr that will only change the way bat 2 charges
  • 3 as above but wire all electronics to bat 2 (pita)
  • 4 leave it as is but install a house battery up front with vsr and wire all electronics off it. 

Pros and cons would be option 4 would be most expensive. But easier to wire up and get to. 

Option 3 would be cheaper but massive dick drag to rewire at the back end. 

 

Anyone think of anything obvious ive missed?

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Date Joined: 04/09/14

Blue sea do a good product

Wed, 2016-10-26 22:18

Blue sea do a good product called add a battery