Solar/split charge VSR query

[BSharp]

Hi could any body tell me if this situation is Norman or ami missing something??
During sunlight
1) voltage at leisure battery showing 13.3v
2) 140A Durite VSR closed (LED illuminated)
3) voltage at starter battery showing 13.3v
Now obviously the 2 batteries will show same voltage as when relay closed they are connected in parallel. So this now makes sense.
I mistakenly thought that the VSR would only sense voltage from one direction but it appears that it senses from either the in or out (SB or LB)
There fore if the solar is above 13.3 v (which it is in direct sunlight) then the VSR will remain closed. My only question would then be is there any issues that when I start van that current will be drawn, if only momentarily from both batteries? Also do anybody know of a VSR relay which only senses voltage from one direction??
I’ve also attached a pic of my set up. Cheers for the reply

 

[Loz]

What vehicle/year do you have, if you have Bluemotion then the VSR is not ideal, a DC-DC charger would be better.

 

[BSharp]

Thanks for reply 2011 T5.1, not a blue motion, no smart alternator.

 

[Deaky]

I had exactly that set up on my T5 with no issues

 

[BSharp]

I think it’s fine just makes me a little concerned that the solar charge controller is set for AGM battery (leisure battery) but with the VSR closed will be charging the starter battery aswell and this is lead acid?

 

[Rich Green]

Hi Bsharp I’m no expert on the leisure battery side of things however I wouldn’t expect that set up to be an issue As your standard battery is only 12v dc so the additional is only the top up charge. The relay would close with the increase of voltage from the solar panel or alternator to charge the cells. Worst case you draw a small charge out the leisure battery and replace it as you drive. Best case you have two charged batteries

 

[BSharp]

Hi Rich, that’s pretty much what I thought after thinking it through a bit.