Jump to content

Strange battery wiring

Ex- Member

By Ex- Member
in Boat Building & Maintenance

 Share

Featured Posts

Ex- Member Veteran II

Ex- Member

Posted
Posted (edited)

A fellow boater is moored along from us, he tapped on the side of the boat this morning with an electrical problem, basically no power.

 

He only got the boat 2 days ago and this morning all his batteries are completely flat 11.10v

 

We've removed what I think is the main engine battery, I don't understand how this set up is supposed to work, aparrently his surveyor instructed a boat yard to wire the batteries in this manner,

 

The battery on the left I believe is meant to be the starter battery, the 2 on the right leisure batteries, the surveyor also had one of the leisure batteries replaced with a new one, the boat owner doesn't know how old the other one is. All a bit strange IMO

 

Anway I'm currently charging up the main engine battery for him on our boat so when replacing it I'll isolate the leisure batteries and concentrate on getting the engine running.

 

What I can't get to grips with is how are these batteries supposed to be charged wired in this manner, It all looks a right mess IMO

 

Possibly the charge is going to the battery switch and you have to have it set in the right position to charge, I'll get a closer look tomorrow, any thought appreciated though.

 

Batterymess1_zpsf1fcb8af.png

Edited by Julynian
Link to comment
Share on other sites
Pete & Helen Proficient

Pete & Helen

Posted
Posted

A fellow boater is moored along from us, he tapped on the side of the boat this morning with an electrical problem, basically no power.

 

He only got the boat 2 days ago and this morning all his batteries are completely flat 11.10v

 

We've removed what I think is the main engine battery, I don't understand how this set up is supposed to work, aparrently his surveyor instructed a boat yard to wire the batteries in this manner,

 

The battery on the left I believe is meant to be the starter battery, the 2 on the right leisure batteries, the surveyor also had one of the leisure batteries replaced with a new one, the boat owner doesn't know how old the other one is. All a bit strange IMO

 

Anway I'm currently charging up the main engine battery for him on our boat so when replacing it I'll isolate the leisure batteries and concentrate on getting the engine running.

 

What I can't get to grips with is how are these batteries supposed to be charged wired in this manner, It all looks a right mess IMO

 

Possibly the charge is going to the battery switch and you have to have it set in the right position to charge, I'll get a closer look tomorrow, any thought appreciated though.

 

Batterymess1_zpsf1fcb8af.png

 

This is when you dont have any charge management or split diodes to control the charge. The switch will be wired so that the feed from the alternator can charge either the starter, the leisure, or both sets of batteries. the norm is that you charge both when the engine is running then switch to one bank when engine is off, this will disconnect the short between both banks so you don't discharge the starter battery when draining the leisures. he probably had the switch set to both and thats whats drained the starter

Link to comment
Share on other sites
Kae Community Regular

Kae

Posted
Posted

Also note you should not switch the switch over whilst charging, set to both before starting the engine.

This may help on how they are usually wired up...

1-2-both_zps882fac1e.jpg

 

The switch should be a "make before break", so this shouldn't be an issue, but you'd have to check the specifications for the particular switch in the installation :)

Link to comment
Share on other sites
Ex- Member Veteran II

Ex- Member

Posted
  • Author
Posted

Thanks that makes a lot of sense. Helen Pete and everyone

 

I had an inkling it was something like that, never come across that particular set up before.

 

Well his engine battery is getting a really good charge so hopefully we can get their engine going tomorrow, I had a small spare battery in our wee van I keep for emergencies, we tried it but it wouldn't turn the engine quick enough to fire up, just 400 cranking amps.

 

Their boat only uses 12v lights and pumps but uses a small inverter to charge lap top, I'll suggest they use a 12v reg charger possibly.

Link to comment
Share on other sites
Robbo Veteran II

Robbo

Posted
Posted (edited)

 

The switch should be a "make before break", so this shouldn't be an issue, but you'd have to check the specifications for the particular switch in the installation smile.png

 

I did read it somewhere, think it was Nigel Calder's book, but don't have access to it at the mo.

He could just dump the switch and replace with a relay to creat a split charge relay?

 

Saves remembering to switch over.....

 

Just shove a Voltage Charging relay in the middle of the batteries (fused both ends) like, the switch is for isolating the batteries as well, so is needed.

 

2batt_1eng_2.png

Edited by Robbo
Link to comment
Share on other sites
ditchcrawler Veteran II

ditchcrawlerDonate to Canal World

Posted
Posted

Also note you should not switch the switch over whilst charging, set to both before starting the engine.

This may help on how they are usually wired up...

1-2-both_zps882fac1e.jpg

So you start the engine with the house batteries?

He could just dump the switch and replace with a relay to creat a split charge relay?

 

Saves remembering to switch over.....

He would then need to add two Isolator switches for the batteries

Link to comment
Share on other sites
jonathanA Experienced

jonathanA

Posted
Posted

by the sounds of it though he has got it wrong and now has flat batterys, so an automatic relay system is the way forward...

Or perhaps someone just needs to explain how the system is supposed to be used.... and he can see if he can live with it or needs an automatic systems such as a split charge. There is nothing wrong with this sort of arrangement its just fallen out of fashion as its been superceeded by automatic versions and 'clever' alternator /battery management systems. (which may have some advantages in some cases)

Link to comment
Share on other sites
Dave Payne Influencer

Dave Payne

Posted
Posted

If you replace the switch with a relay you dont have a battery isolator

Ahh yes!

Or perhaps someone just needs to explain how the system is supposed to be used.... and he can see if he can live with it or needs an automatic systems such as a split charge. There is nothing wrong with this sort of arrangement its just fallen out of fashion as its been superceeded by automatic versions and 'clever' alternator /battery management systems. (which may have some advantages in some cases)

 

 

To add two isolator switches and a relay system would cost a lot less than a management system though would it not?

Link to comment
Share on other sites
by'eck Veteran

by'eck

Posted
Posted (edited)

My first boat a 1991 Moody 35, had the same system with two identical batteries. No dedicated start or domestic, and was as supplied by the well respected prolific manufacturer.

 

You chose to take current from battery one, two or both. The alternator and single output mains charger also were given the same chosen load.

 

There was also an Off position on the four way switch to provide complete battery isolation.

 

The switch contacts were make before break so you could switch charge to any of the three battery selection positions with engine running without issue, although not Off of course.

Edited by by'eck
Link to comment
Share on other sites
Ex- Member Veteran II

Ex- Member

Posted
  • Author
Posted

Following on from this I have another question for my own information.

 

We have 2 alternators, one for leisure and 1 for engine bat.could we put one of these 1-2 & both switches on our alternator dedicated to engine to divert charge to the main bank?

 

I know diodes could do this, but a manual option would be preferable especially for when bulk charging. Our main Alternator is 70a and eng bat alt 50a

Link to comment
Share on other sites
by'eck Veteran

by'eck

Posted
Posted

Following on from this I have another question for my own information.

 

We have 2 alternators, one for leisure and 1 for engine bat.could we put one of these 1-2 & both switches on our alternator dedicated to engine to divert charge to the main bank?

 

I know diodes could do this, but a manual option would be preferable especially for when bulk charging. Our main Alternator is 70a and eng bat alt 50a

 

Should work as long as switch contacts are make before break so there is no possibility of either alternator being without some battery load even momentarily.

Link to comment
Share on other sites
Dave Payne Influencer

Dave Payne

Posted
Posted

Following on from this I have another question for my own information.

 

We have 2 alternators, one for leisure and 1 for engine bat.could we put one of these 1-2 & both switches on our alternator dedicated to engine to divert charge to the main bank?

 

I know diodes could do this, but a manual option would be preferable especially for when bulk charging. Our main Alternator is 70a and eng bat alt 50a

 

 

Does the power go from alternator to fancy management device then to batterys in your set up?

Link to comment
Share on other sites
Ex- Member Veteran II

Ex- Member

Posted
  • Author
Posted

 

Should work as long as switch contacts are make before break so there is no possibility of either alternator being without some battery load even momentarily.

 

Thanks by'eck

 

How is make before break achieved a specific type switch?

 

 

Does the power go from alternator to fancy management device then to batterys in your set up?

 

No the lead from the alternator goes direct to the engine battery, the neg lead is bolted to the engine block.

Link to comment
Share on other sites
Dave Payne Influencer

Dave Payne

Posted
Posted

 

Thanks by'eck

 

How is make before break achieved a specific type switch?

 

No the lead from the alternator goes direct to the engine battery, the neg lead is bolted to the engine block.

 

 

Sorry, i meant from your main alt to your domestic bank, does this go direct or though a fancy bit of kit?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.