Split Charge Relay replacement

[kevinmo]

The split charge relay on my boat has burnt out. Once I eventually found it I could test the coil and found it had shorted out.

Should I replace the relay directly or would it be a good idea to replace it with split charge diodes?

Replacing with diodes will need some rewiring as the alternator output is connected to the starter solenoid and from there back to the starter battery and the domestic battery bank via the split charge relay.

I also have a Stirling, 4 Step Alternator Regulator installed.

I am also a bit unsure of what cable size I will need to connect the alternator to the split charge diodes, if I go down that route.

Any help and observations from the forum is welcome.


Kevin.

 

[Tranona]

Suggest you rewire and change to a VSR. Lower losses and longer life. BEP Marine from Merlin at www.power-store.com can supply all the bits and a wiring diagram.

 

[moody1]

[ QUOTE ]
Suggest you rewire and change to a VSR. Lower losses and longer life. BEP Marine from Merlin at www.power-store.com can supply all the bits and a wiring diagram.

[/ QUOTE ]

Or "KDDPower" - who posts on here

 

[oilyrag]

With a Sterling alternator regulator fitted, the cheapest, simplest solution is to fit a Sterling diode. They cost around £30 for the 1 alt/2 battery bank version. The only downside to these is the voltage drop but the Sterling regulator overcomes this. Even without a 4 step regulator for example, the volt drop across my set-up is 0.8v but the alternator (standard Volvo 70amp, battery-sensed) pushes out up to 15v to overcome this. My set up, as it came with the boat, has 4sq.mm cable from the alternator to the diode and from diode to batteries. I have no reason to doubt this is inadequate but have no idea - no doubt others will comment if otherwise...

 

[halcyon]

[ QUOTE ]
My set up, as it came with the boat, has 4sq.mm cable from the alternator to the diode and from diode to batteries. I have no reason to doubt this is inadequate but have no idea - no doubt others will comment if otherwise...

[/ QUOTE ]

Are you sure it is 4 mm, I would not use that for much over 30 amp, would have gone with 10 sq mm minimum, probably 20 sq mm.

The concideration going to diodes is as said, it will require re-wiring the charging system. Plus you are adding an additional failure point in the charge line. As it is now the alternator is always connected to the engine battery. Adding the diodes you have added a possible diode failure, and two more terminals to corrode or fail.

With the relay system the only thing you can loose is charge to the service battery. This can be easly by-passed by moving the service cable to the engine battery terminal.

Brian

 

[RestlessL]

I use 4AWG (21 sq mm) cable for the alternator feed, and also the feed from the house battery to the main distribution block.

John