Testing a VSR.

[potentillaCO32]

I Have installed a VSR between my isolated house bank and starter battery with an emergency start cut over switch. As discussed and suggested on here many times.

If i want to test that the VSR is working, is my assumption that i just charge one battery and the voltage across the other battery should rise as the VSR detects the other battery needs charging as well correct?

 

[PaulRainbow]

I Have installed a VSR between my isolated house bank and starter battery with an emergency start cut over switch. As discussed and suggested on here many times.

If i want to test that the VSR is working, is my assumption that i just charge one battery and the voltage across the other battery should rise as the VSR detects the other battery needs charging as well correct?

Correct.

 

[VicS]

I Have installed a VSR between my isolated house bank and starter battery with an emergency start cut over switch. As discussed and suggested on here many times.

If i want to test that the VSR is working, is my assumption that i just charge one battery and the voltage across the other battery should rise as the VSR detects the other battery needs charging as well correct?

You have the right idea but that's not how a VSR works. The VSR is sensing the voltage at the battery being charged . When that rises to the "connect voltage" typically around 13.5 volts the relay will close to begin charging the second battery regardless of its state of charge . If the voltage drops to below the somewhat lower "disconnect voltage" the relay will open.

Most modern VSRs are bidirectional i.e. will operate which ever battery is being charged. They will sense the starter batter being charged by the alternator or the house battery being charged by a battery charger, or a solar charger etc.
.

 

[potentillaCO32]

Correct.

Thanks Paul.
Re wire finally finished, now onto the engine. Switching on the battery for the first time was a worryimg moment and a good anti climax as everything worked.

 

[lustyd]

If rewiring hopefully you’ll know there’s no split charge relay, but if you’re not certain it may be worth disconnecting the VSR to check first.
Our boat had a VSR possibly since new, but they didn’t remove the original Volvo relay so the VSR wasn’t doing anything useful other than lighting up when the engine ran. Both now replaced with DC-DC charger.

 

[potentillaCO32]

No split chrage relay