Voltage Sensing Relay - Recomendations

[Andrew_Trayfoot]

Any recomendation on a VSR?
@PaulRainbow what are you currently recmending?

 

[laika]

I have a blue sea one which works well except for an annoying feature I discovered soon after leaving Alderney after a few days on a buoy. It won’t combine batteries if the voltage on one is too low. So when planning an installation do consider installing an emergency manual battery combiner to avoid the necessity of heavy duty cable gymnastics in bumpy weather

 

[B27]

I have a blue sea one which works well except for an annoying feature I discovered soon after leaving Alderney after a few days on a buoy. It won’t combine batteries if the voltage on one is too low. So when planning an installation do consider installing an emergency manual battery combiner to avoid the necessity of heavy duty cable gymnastics in bumpy weather

That is arguably a very sensible feature, connecting a big flat house bank to your start battery may not be a good idea!
How flat is 'too flat' though?

 

[richarddbarker]

Have a look at Victron Cyrix CT, it supports bidirectional connection and can be wired for start assist.

 

[VicS]

That is arguably a very sensible feature, connecting a big flat house bank to your start battery may not be a good idea!
How flat is 'too flat' though?

The under voltage lockout for BlueSea VSRs is 9.5 volts . . . . It's in the specs on their website

 

[lustyd]

I think a lot of them disconnect under engine start conditions anyway so you'd want the manual switch either way surely?

 

[PaulRainbow]

Any recomendation on a VSR?
@PaulRainbow what are you currently recmending?

Victron Cyrix Andrew

 

[laika]

That is arguably a very sensible feature,

It is and I see the reason. But when your autopilot starts beeping low voltage at you and starting the engine doesn’t solve the problem, you wish you’d thought to install the manual link

 

[B27]

I think I'd rather avoid my house battery getting down below 10V.

 

[Supertramp]

Probably obvious, but fit a battery monitor to show the house and engine battery voltages. Invaluable for checking what's going on and monitoring charge state.

I recently had a charging problem and it gave me a lot of confidence from monitoring the battery voltages that I could start and run the engine for hours and that the house batteries would run the autopilot and navigation stuff. Possibly my most frequently used instrument!

 

[pmagowan]

View attachment 158792

BEP Switch Cluster and VSR​

Operation	Switch Positions	Effect
Normal On	House and Start On, EP Off	House and Start systems connected to their respective batteries independently. VSR will activate to parallel batteries for charging when engine running
Emergency Parallel	All switches on	Both batteries are joined in 1 bank
Start from House	Start Off, House On, EP On	Start battery will be isolated. House battery will power all systems
Power from Start	Start On, House Off, EP On	House battery will be isolated. Start battery will power all systems
All Off	All Off	Engine and all switched loads will be isolated. Charger and unswitched loads will remain powered

This is my solution which is with BEP but can be done with any DVSR, allows for isolation of each battery for engine start or house loads. Prevents issue with over discharged battery leading to non-functioning system. Is wired different to the BEP standard wiring. The shunt is there for monitoring.

 

[Andrew_Trayfoot]

There is another thread running on VSRs which is getting very technical (and slightly grumpy) so I'm going to keep off that one..

So some advice on wiring the VSR would be helpful...

My setup is as follows:

Boat lines on a mooring.

70a alternator (beta)
30w solar panel with 2 battery charge controller (engine battery priority)
Engine battery
Domestic battery 2x110ah
2kw inverter
Microwave (engine running while in use)
Cool box (wired via a relay to only run if the engine is on)

Currently 1:2:Both switch.

So how do I wire it so:

Cool box only runs with engine (curreny relay from key swich)

Solar panel does no confuse the VSR..

Inverter/microwave does not touch the engine battery. (Curreny the 1:2:both is set to domestic (1) only so what the alternator is not providing comes from that). Note it is only ever run for 6 or 8 minutes in 2 minutes blocks.

 

[PaulRainbow]

Or if you must keep the 1-2-B just connect the 1-2-B as above. You can leave the coolbox on the relay. The solar controller would be best connected to just one battery bank, probably better to use the domestic bank.

 

[Andrew_Trayfoot]

Or if you must keep the 1-2-B just connect the 1-2-B as above. You can leave the coolbox on the relay. The solar controller would be best connected to just one battery bank, probably better to use the domestic bank.

Thanks Paul

 

[PaulRainbow]

Should have been a schematic in post #13, for some reason the forum doesn't show images from a link !!

 

[Andrew_Trayfoot]

@PaulRainbow
Am I missing something or should there be a connection from the alternator to the VSR?

 

[Andrew_Trayfoot]

@PaulRainbow sorry, just looked at the Victron web site - undersand how it works now