Voltage Sensitive Relays (VSR) & Battery-to-Battery Chargers Explained | 12 Volt Planet

In this video we explain the differences between Voltage Sensitive Relay VSR's and Battery-to-Battery chargers.

12 Volt Planet is an online supplier of low voltage electrical components and accessories for the auto, marine and leisure after-markets.

If you have any questions then please leave a comment.

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[neilwilliams]

Very good tutorial 👌. Straight forward and to the point of the matter.

[SterlingPowerLtd]

Hi 12V Planet!

Thank you for this video, it's concise and informative to the consumer.

Cheers!

[ianjamiesonmusic]

Do you also need to connect the DC charge controllers to the alternator or the ignition to stop it draining the battery when the engine is not running? Or does it work this part out itself like the VSR does?

[Brasilianer]

Hi, If I have a solar panel on my lasher battery, is the VSR also working in the other direction to the starter battery?

[charlessterling]

Great description. Love it. Charles sterling the designer off the bat to bat. Well done

[petersmith]

thank you. My Voltage COntrol Relay box (which I am assuming is the same thing) has two posts. One is marked closed 12v and the other is marked Open 12.8. Buggered if I know which goes to the car and which one to the van. I have currently got the 12.8v going to the van.

[Bobbyjoe]

Very helpful information, now I know what I'll be doing exactly for my project.
Thank you!

[paullockyer]

Any idea why my VSR keeps clicking? I have it connected to leisure battery (AND solar panel via controller). I can isolate it from starter battery & from leisure battery. The VSR works fine when I turn engine on. Whilst in my van with engine off it starts clicking like crazy. When I isolate it from start battery clicking continues. When I isolate it from leisure it stops. There was a yellow wire in VSR that if connected allowed a closed circuit between both batteries. I just left this inside & unconnected. I then cut it off down to 5mm but this did not stop the clicking either. - thanks Paul

[roostaraver]

Excellent video, I'm in the process of fitting a 90ah AGM leisure battery in my van on a split charge system from my starter battery as in your video, I have a vsr relay but would it be better to fit a battery to battery charger instead of the vsr to charge the AGM battery? Or will a vsr be ok

[markaxelby]

Hi, great video ! I am converting a van to a camper .May I ask if its possible to connect a solar system whilst retaining a VSR, to work in conjunction ? And if so do you sell the components to do this ? TIA

[Amer-ylgb]

Can I use a VSR to feed the DCDC charger? The DCDC charger that I have is not smart and will not disconnect with engine off... it does have a ignition feed but I dont want to open up the dashboard to find the ignition wire...

[kenmackenzie]

Hi I have bought a Renogy 40Amp DC/DC charger it does not have a voltage sensitive relay fitted only a wire which is connected so when you start up the van it starts to charge the house batteries. I could fit a on off switch but I might forget to switch on LOL. Could i fit the sensative relay you mention before my renogy DC/DC charger that way it would be voltage sensative or would it still not work? I have a smart alternator fitted as standard in the 2016 sprinter. If this does not work can you suggest anything? Is there a voltage sensative relay for lithiums?

[daveblogs]

Hi. Great vid. 👍
I have a portable power Technologies split charge relay ( the Green one as in your thumb nail..) fitted to our campervan.
It had been working great..but has now started clicking every couple of seconds when the leisure battery falls to around 12 6 Volts.(with engine off) Sometimes the clicking doesn't happen at all..but mostly yes.. so I.m not sure .is it a dying battery..or faulty VSR? The red light seems to be on all the time.
Tia if you have any ideas..👍

[shaunmccaw]

Hi there bought a vsr split charger for my Vauxhall vivaro it's got a smart alternator in it when I heard it doesn't work i sent it back but the seller insisted that it still works with a smart alternator do you think there's any truth in this

[azmisalleh]

I want to limit my current from 200A alternator to charge 280Ah LiFepo4 battery. Can I use a VSR to limit the current let says only 100A? What should I use?

[thomaspalmer]

Hi there, great video!
I have a 220AH deep cylce AGM battery.
Would either of these 2 options be suitable? i saw something below that you cannot use these methods to charge an AGM batttery. thanks alot

[firmbutton]

How about adding into the mix the alternator to battery charger?

[BigSkiSale]

What if I have two leisure batteries onboard that I'd like to charge? Could I use a VSR to connect the starter battery to leisure battery #1, and then put a battery-to-battery charger from that to leisure battery #2? Thanks!!

[Hjexecutivetravel]

What happens if you use this if a smart alternator is on. I have one installed, it’s working but I think the vehicle is a smart alternator as it’s an 18 plate merc v class with euro 6 engine. Every now and again battery warning light comes on dashboard then goes off when I restart engine. Any advice much appreciated. I’ve also subscribed, thanks

[ylemoine]

Great explanation, thank you. Do VSR’s fail and how do you diagnose them? I have one on my boat and it is intermittent that it is charging my house bank. The light on the front says it should be, but the house doesn’t see the charging voltage and continues to feed house loads and discharges. Any help is appreciated.