Victran SmartShunt setup question. Can/should it be switched?

[MagicalArmchair]

Hello all,

Question: The below set up leads to there being a constant draw on the batteries, as the shunt is not switched. Is that usual? I'd much prefer to put a switch in the positive sides of the below to stop it draining my battereis when not attached to shore power? What do others do?

The set up on my Bavaria 40 had a common negative, as the below. The battery on the right is the engine starter battery (1 x 80Ah), the two at the bottom are the leisure batteries (2 x 220Ah).



The setup suggested by Victron is below:


Leading to the following install. The blue circle is the Shunt. The red lined lead in the below is a new cable I made up from the negative of the engine battery to the load side of the Shunt. The green at the top is the load, and the green at the bottom is the negative to the leisure batteries.



It all works, but will it kill my batteries when I am away?

 

[Sandy]

Question 1. Yes - the shunt and other Victron devices draw some power to work, chat to each other via BlueTooth.

Question 2. No - unless you are away for a very long time.

Check your Victron documentation and calculate the power usage - my system draws a couple of amp hours per day. My solar panels more than replace that.

If you don't have solar and are planning to be away from the boat for some time remove the fuses from the +ve lines. That removes the power from the kit and stops any data logging you might be doing.

p.s. I've replaced the glass fuses with blade ones as I refuse to have glass fuses on the boat.

 

[VicS]

Hello all,

Question: The below set up leads to there being a constant draw on the batteries, as the shunt is not switched. Is that usual? I'd much prefer to put a switch in the positive sides of the below to stop it draining my battereis when not attached to shore power? What do others do?

It all works, but will it kill my batteries when I am away?

According to the data sheet the current draw is less than 1mA

Are you measuring more than that?

 

[salar]

I have my Victron Smartmeter setup exactly as Victron requires it and it has given no problems at all. The current draw is negligable - less than one thousanth of an amp so to reduce a 100aH battery to half charge you would have to leave your boat for 5.7 years.

 

[MagicalArmchair]

Thank you all, that is great news there is nothing else I need to do to!

 

[MapisM]

Aware as I am that the current absorption is negligible, I also struggle to see the point of having any device turned on while it's not being used at all, in principle.
For this reason, I connected the positive of my SmartShunt just downstream of the relay that disconnects the batteries.
This way, whenever I'm onboard (and/or I deliberately leave the batteries connected, regardless of whether connected also to shorepower or not), the SmartShunt does its job.
But when for instance the boat is sheltered and completely "dead" (as it is now), the SmartShunt is also off.
Then again, each to their own on that!

 

[Sandy]

Aware as I am that the current absorption is negligible, I also struggle to see the point of having any device turned on while it's not being used at all, in principle.
For this reason, I connected the positive of my SmartShunt just downstream of the relay that disconnects the batteries.
This way, whenever I'm onboard (and/or I deliberately leave the batteries connected, regardless of whether connected also to shorepower or not), the SmartShunt does its job.
But when for instance the boat is sheltered and completely "dead" (as it is now), the SmartShunt is also off.
Then again, each to their own on that!

Really depends on how you look at power management.

With all of the Victron devices on and talking to each other if you have solar then you get a really good picture of what is going on and charging is done in the most effective way. If you don't have solar then unplugging them is fine.

 

[justanothersailboat]

And since these drive a battery monitor - that's probably best left on so that it can detect whether the battery is actually holding up its voltage over time under no load as well as when you turn it on and loads are applied. I have no idea if it uses this cleverly but since voltage is part of its battery state calculation, it made sense to me to leave it in all the time, it's being used to monitor the battery. As it happens, the load of shunt + monitor together is really low and my single house battery would feed it happily for years.

Would you ever connect a load that deliberately bypassed the master "off" switch? Perhaps an automatic emergency bilge pump or a gas alarm?

I think there's also a setting that controls what the meter assumes when powered off and back on. It was mentioned in another thread recently: Do I need new leisure batteries? (Victron setup) ... anyway if it's fully disconnected the meter has to assume something; if it's on all the time it doesn't. That's enough to justify a milliamp, to me.