How would you wire a starter battery-house bank connection

[earthbm]

I have an automatic charging relay that separates the starter battery when under sail to not deplete it, and reconnects the batteries when on shore power or motoring.

Except that it is not working quite like this. When I manually disconnect the relay there is no voltage on the starter battery wire that goes into it. As if the starter battery has zero voltage. So to start the engine I need to manually connect the house and starter batteries. Checking at the starter battery (when the relay is disconnected) I have 13.4v so it does charge from the shore power. So somewhere between the starter battery and the relay connection breaks, but one way! The starter battery gets charged, but it doesn't give any power back, so to start the engine I need to connect the house bank. As if it's a one-way connection.

At the end of my wits here, the Chinese puzzle is killing me. Is there a standard wiring diagram for the starter battery, the house bank, charging relay, starter battery on/off switch?

[Albro359]

Are you sure that wire is the starter battery wire and not the wire from the alternator ? Sounds to me that it is miswired.
The alternator wire should go directly to the house bank. Then there should be a wire from the house bank to the relay to tell the relay when the alternator is running. Another wire from the start battery to a contact on the the relay and when the realy operates (the volts from the house bank energise it) the realy closes and parallels the house and start banks.
I think you need to trace the wiring and find out exactly where each wire goes. There's no such thing as one-way wires !...UNLESS you also have a diode isolator in the circuit somewhere ????
Did it ever work ? If so, what changed between then and now?

[Shanaly]

have a look at the website for Sterling electronics in the uk. they have similar regs for sale and some helpful diagrams and pdf online before you buy. I think this could clear up your confusion . good luck, fair winds, high amp charging....

[earthbm]

Originally Posted by Albro359

Did it ever work ? If so, what changed between then and now?

It used to work fine, then during an 8-day passage the voltage on the starter battery started dropping, to the point where the relay was automatically disconnecting it. Since then I replaced the starter battery (with Lifeline AGM) and the relay. Since then the voltage on the starter battery sensor dropped first to 8v then to 0v.

It's very hard to trace the wires without ripping open plastic panels.

[Kettlewell]

Is the "relay" a solenoid or is it a "combiner?" Maybe I am misunderstanding what you are saying, but usually the wire from the starter battery to the starter will not go back through the relay, but will instead go direct to the starter, possibly through a simple on/off switch or through a 1,2,3 switch. So, as long as there is sufficient juice in the starter battery, and the switch is turned on, the starter should work. This starter cable from the starter battery must be a big, thick, usually red cable.

[marine1]

Who's ACR are you using?

[Fiveslide]

Originally Posted by earthbm

It's very hard to trace the wires without ripping open plastic panels.

That's not what he meant by that. Just test for continuity with your meter.

When, or if, you find a problem like he described, then you can worry about that particular wire location.

[cszosler]

[QUOTE="earthbm;1189782"]I have an automatic charging relay that separates the starter battery when under sail to not deplete it, and reconnects the batteries when on shore power or motoring.

hi,
is your relay VSR voltage sensitive relay?

[marine1]

A good ACR is Bluesea PN 7610. It sense voltage rise on either bank so house can have a land charger but still charg the start and when the start Batt is being charged by the alternator the house gets charged. It also has the option of a "sense"line that disconnects the batteries during starting. Used them for years and they work great.

[gspeak]

I think he is talking about something like this.

Continuous Duty Solenoid

I have two of these hooked up in my Lagoon that I want to get rid off also as they run very hot when the motor is running & charging. I'm pretty sure they are triggered to parallel the house & start batts when the ignition is turned on. Just have to work out how to replace with a combiner or something.

I don't know why there is 2 off them as only the port motor charges the house batteries. Any clues?

Dave
Seabreeze L380 #241

[earthbm]

The relay is Blue Sea ACR 7622

You'd think that once the engine switch (also Blue Sea) is on there should be nothing between the starter battery and the motor, but this is not the case.

[cal40john]

After rereading your post several times all I can figure out is that you must have somehow miswired it when you replaced the old ACR. The wire that you think comes from the start battery has to be at the same voltage as the battery, unless it is broken.

Also is it possible that you have a 2 bank shore power charger, so it would charge the start battery independent of the ACR?

[marine1]

Switch to a 7610 by Bluesea. I have had trouble with the sense circ on the 7622 and have change a few out because of it. The 7610 has one wire tied to the start circ , one for ground and then just ties the batteries in on the main lugs . Done and they don't fail.

[earthbm]

Thanks. 7610 does look more bullet proof, even I can understand all instructions. It does however need a separate switch to combine battery banks for emergency starts. Right now my 7622 manual switch combining the banks is permanently on as a "temporary" fix. If I just install 7610 and the underlying issue is elsewhere this could create a problem.

Looking at the starting battery, there is only one orange cable connected to it. I thought there should be two orange cables - one to the engine start switch and another to the Blue Sea charging relay. Where's the next most logical place for the two to be split? At the engine start switch?

[earthbm]

I have not been able to figure this out and now the problem is getting worse - sometimes power to the motor goes out even when it's running.

Here's another attempt to describe the symptoms:

When unplugged from shore power the parallel battery switch on the electric panel turns off after a while (10 minutes). I guess it's as expected to prevent autopilot/instruments/etc draining the starter battery. However when this happens the voltage on the starter battery circuit as shown by the panel indicator goes to zero (0.0) and the motor can't be started at all. Sometimes the parallel switch even switches off when the motor is running and the engine stop button can't be operated. I have replaced the starter battery to fix this and it didn't help. I replaced the Blue Sea ACR and it didn't help. If there is a break in the starter battery circuit then why does the parallel switch stay on for a while? This happens even with the manual switch on the Blue Sea ACR (7622) in the "parallel" mode.