Battery / alternator issues again!

[Keithleask]

Have been having issues with battery charging etc for quite some time now with the domestic batteries. Looking at how all three banks are connected, 2 domestic batteries and four for the two engines I notice that the four batteries for the two engines are wired back to my newmar abc 12-40 amp three bank charger. The charger has a common neutral and three charging leads but these charging leads only go to the engine starting batteries. Alongside and part of the charger is a finned like metal connector block that has returns from the batteries, 6 number, from this connector block 4 cables go to both alternators. Question is how do the domestic batteries receive a charge if they are not connected to the charger?, I am thinking the engines need to be running to put a feed back to the connector block which in turn supplies a charge to the domestic battery . Does that sound correct? If so then it means that if the boat is standing for any light of time the domestic batteries will run down? Is that right?any help greatly appreciated!

 

[VicS]

Have been having issues with battery charging etc for quite some time now with the domestic batteries. Looking at how all three banks are connected, 2 domestic batteries and four for the two engines I notice that the four batteries for the two engines are wired back to my newmar abc 12-40 amp three bank charger. The charger has a common neutral and three charging leads but these charging leads only go to the engine starting batteries. Alongside and part of the charger is a finned like metal connector block that has returns from the batteries, 6 number, from this connector block 4 cables go to both alternators. Question is how do the domestic batteries receive a charge if they are not connected to the charger?, I am thinking the engines need to be running to put a feed back to the connector block which in turn supplies a charge to the domestic battery . Does that sound correct? If so then it means that if the boat is standing for any light of time the domestic batteries will run down? Is that right?any help greatly appreciated!

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Id say that the 3 outputs from the charger should go directly but independently to the battery three banks. There is presumably a common negative for the whole lot.

First thoughts were that the finned device might be a diode splitter to combine the output from the alternators and split it between the three battery banks ...... but perhaps something else if truly part of the charger.

A diagram is worth a thousand words when trying to explain and understand electrical systems.

Spend a little time doing a clear diagram. Scan it, or photograph it, and post it .

 

[halcyon]

Have been having issues with battery charging etc for quite some time now with the domestic batteries. Looking at how all three banks are connected, 2 domestic batteries and four for the two engines I notice that the four batteries for the two engines are wired back to my newmar abc 12-40 amp three bank charger. The charger has a common neutral and three charging leads but these charging leads only go to the engine starting batteries. Alongside and part of the charger is a finned like metal connector block that has returns from the batteries, 6 number, from this connector block 4 cables go to both alternators. Question is how do the domestic batteries receive a charge if they are not connected to the charger?, I am thinking the engines need to be running to put a feed back to the connector block which in turn supplies a charge to the domestic battery . Does that sound correct? If so then it means that if the boat is standing for any light of time the domestic batteries will run down? Is that right?any help greatly appreciated!

One output of the three on the mains charger should go to the service battery to charge from the mains.

Check the fitting instructions incase there is a dedicated terminal for service battery.

Brian

 

[VicS]

Exactly what model is the battery charger ?

I only found dual , not triple, output ABC series chargers and only 8 or 25 amp output , not 40 amps, on Newmars website

There is however a triple output 40 amp ABS certified charger .... model PT-40U

 

[Keithleask]

Vic hi thanks for the reply, I was wondering if what I am calling the finned device could actually be a diode splitter? I am thinking like you that one of the three charger cables should go to the service battery. It has been wired in like this since I bought the boat over a year ago now! I have some photos of the charger etc if that would help, there is one common neutral but not to the service battery

 

[VicS]

Vic hi thanks for the reply, I was wondering if what I am calling the finned device could actually be a diode splitter? I am thinking like you that one of the three charger cables should go to the service battery. It has been wired in like this since I bought the boat over a year ago now! I have some photos of the charger etc if that would help, there is one common neutral but not to the service battery

Photos might help but a diagram is really what's needed


I d expect the domestic services and the engine electrics to have a common negative...... they must have if they are all charged from the same engine alternators.

 

[Keithleask]

Vic yes it's a Newmar ABC 12-40 amp it was a special but is almost identical to the 45 , newmar sent me a manual for the 45 and this shows two methods of connecting the batteries in parallel . Simple system shows each bank being supplied individually with positive supply and common neutral. The connection with the battery switch is a bit more complicated with a switch for the engine starter and a load group coming from this switch. There is a negative bus from the third bank and another load group. I am wondering why the batteries are connected as they are if the manual shows three separate feeds?

 

[Keithleask]

Brian, thanks my thinking too, the manual shows the batteries being supplied separately from the charger but that's not how they are wired on the boat!

 

[Keithleask]

Vic see sketch attached hope it's clear enough?