Help needed with hookup charging of two batteries

[MagicWagon]

I will soon be installing mains hookup to my 1983 Devon camper. I'm happy with that having done it on my 1981 autosleeper, but this time want to install an intelligent charger and I want it to charge/maintain the leisure and the starter batteries.
I have wired split charging for the leisure battery via the alternator using a voltage sensitive relay and that is working fine.
To achieve dual charging on mains hook-up, do I need a charger with more than one output such as this one
https://www.12voltplanet.co.uk/victron- ... utput.html" onclick="window.open(this.href);return false;
or, do I just need a single output one hooked up to the starter battery ?
I'm wondering if the VSR would get activated when the starter battery is on charge, and therefore also charge the leisure battery.
Even if that did work, how would the "intelligent" part of the charger work if it is connected to both batteries, as I don't see how it could independently detect the condition of each.
Would I be better off with a separate charger for each battery ?
Many thanks to anyone who can advise on this.

[bigherb]

To achieve dual charging on mains hook-up, do I need a charger with more than one output such as this one
.

In short, yes.
You shouldn't charge two dissimilar charged/capacity batteries where the charger can take the charging above the gassing level of the battery smart chargers can if only for a short period. It is OK with vehicle alternators as they set to charge below the gassing level of a battery.

I'm wondering if the VSR would get activated when the starter battery is on charge, and therefore also charge the leisure battery.

Yes it can do, some even switch on if the leisure battery is being charged, usually best to switch off the VSR by fitting a switch into the earth of the VSR.

[MagicWagon]

Many thanks for your helpful reply.
If I understand correctly, you are saying that I should disable the VSR whenever I am charging from the mains charger ?
I wonder if there is any way that this could be achieved automatically via some kind of relay ?

[bigherb]

If I understand correctly, you are saying that I should disable the VSR whenever I am charging from the mains charger ?

Yes.

I wonder if there is any way that this could be achieved automatically via some kind of relay ?

It can be done with a 220V changeover relay.
Why do you need to charge both batteries?

[MagicWagon]

It can be done with a 220V changeover relay.

Thanks. I will look this up.

Why do you need to charge both batteries?

I'm thinking the leisure will need charging when I'm on-site, and using up the leisure battery, and it would be helpful to keep the starter battery topped up and conditioned by hooking the van up to mains when it sits unused at home.