VSR Chatter

[Jimmylee]

I have a BEP Voltage Sensitive Relay Module that connects my 24 series cranking and my 24 series deep cycle batteries. I don't ever remember the VSR doing this before, but this past weekend we were on the boat crabbing and between pot pulls I was just floating with the main motor in neutral (115 Etech) and idling and when I went out to the cockpit i heard the VSR cutting in and out. I'm thinking the reason for the cutting in and out of the VSR while the main motor is idling is the result of a slowly dying start battery. Anyone else seen this??

The VSR I have cuts out at 12.8 volts and cuts in at 13.7 volts.

Thanks in advance

Chip

 

[Notayot]

This will happen if at idle your alternator does not deliver enough current to satisfy the needs of the entire electrical system. The pot puller is probably the biggest user, and the alternator is not keeping up. To save the engine battery the relay will temporarily disconnect the auxiliary battery. When the main battery voltage climbs, the relay attempts to charge the auxiliary but since it cannot charge both at the low alternator speed it drops the auxiliary again. This will continue until it is able to hold a voltage between the limits with both batteries charging which may never happen at idle speed. Try the same situation with a higher engine speed. This will probably solve the issue.

It is possible a battery is failing but it is more likely it is just low current at idle speed

 

[potter water]

I use my engine (s) as generators occasionally. Am I at risk running the engine out of gear at high idle for charging purposes even at anchor? It consumes little fuel. I've often wondered if carrying a gas powered generator on the boat wasn't a bit redundant as I can fire up one of the Suzies at a bit over idle and get what power I need for the short periods of time that I might need to run an AC invertor. Yes, the hour meter goes up, but there is very little wear and tear on the engine.

Thoughts?

 

[thataway]

No risk to the Suzuki at a fast Idle, but you are probably only getting 15 amps out of the engine when at fast idle. I use a different approach--and use a Honda EU1000i, which will run the 5000 BTU AC unit, as well as easily run a 30 amp charger to the freezer battery, and a 20 amp charger (total 50 amps) to the house battery. So I am get 50 amps--most likely 3x what you have available, with the same amount of fuel usage, probably less noise. You are certainly not providing enough amperage to run the inverter, just boosting the voltage when it is on.

I do agree about the cause of the chatter--not necessarily a bad or dying battery.