Turning of items running on leisure battery

[Leemondo12]

HI All,

I shortly plan on fitting a second battery along with a dc-dc to keep it charged when driving. The second battery will only be used to run items in the back of the van (Kombi) such as lights, usb chargers etc. nothing fancy. I want to be able to walk away from the van and be sure that any item in the back if left on will turn off, can I just wire a relay in-between the second battery positive and the fuse box? But what to trigger this relay? As I would want to be able to have the stuff in the back running when the engine is stopped.

What does everyone else do?

Thanks Lee

 

[Pauly]

Why ?

The whole point of a separate battery is to power that equipment when the van isnt running and if left on wont affect the engine battery

 

[EAN]

I just use a physical battery isolator switch (Victron 275A) straight after the main battery fuse.
If you want something a bit more elegant then no reason why you couldn't use a suitably rated relay. You could energise it by a switched 12V feed from your second battery and have a single switch on your dash to kill everything running in the back from it.
It will take a small amount of power from your second battery whilst the relay is energised, but will be pretty small.

 

[meza]

Are you wanting to have the leisure battery disconnected when the van is locked? Not sure how to do that in a simple way.

Maybe simpler would be a battery isolator switch on the leisure battery, that would turn everything off?

Or if you're concerned about accidentally running down the leisure battery voltage too low, you could use a low-voltage disconnect:

https://www.amazon.co.uk/Victron-Energy-BatteryProtect-24V-65A-BPR000065400/dp/B01N6ATT8C/ref=asc_df_B01N6ATT8C/

 

[Leemondo12]

Why ?

The whole point of a separate battery is to power that equipment when the van isnt running and if left on wont affect the engine battery

I know, i think i may have created a problem that doesn't exist

 

[Leemondo12]

Are you wanting to have the leisure battery disconnected when the van is locked? Not sure how to do that in a simple way.

Maybe simpler would be a battery isolator switch on the leisure battery, that would turn everything off?

Or if you're concerned about accidentally running down the leisure battery voltage too low, you could use a low-voltage disconnect:

https://www.amazon.co.uk/Victron-Energy-BatteryProtect-24V-65A-BPR000065400/dp/B01N6ATT8C/ref=asc_df_B01N6ATT8C/

I like the idea of this, i could set it to a reasonable voltage and know it wouldn't flatten the battery. Thanks for the suggestion.