Leisure battery in parallel with Start&Stop Battery

[botacco]

I have just bought a 120Ah deep cycle battery for my Custom converted to camper to power a webasto airtop 2000 and a waeco CF35.

How about connecting the battery in parallel with the second battery, so as to benefit of both capacity? Is there any risk?

[Altransit]

You should never 'hard wire' a starter, and a leisure battery, as they have very different usage characteristics.
They can be connected whilst charging, usually via a split charge relay, but you'll kill a starter battery if you constantly drain it whilst in leisure use, and you'll kill a leisure battery by using it for starting

[botacco]

You should never 'hard wire' a starter, and a leisure battery, as they have very different usage characteristics.
They can be connected whilst charging, usually via a split charge relay, but you'll kill a starter battery if you constantly drain it whilst in leisure use, and you'll kill a leisure battery by using it for starting

Thank you. The second battery (connected to the Start and Stop) is an AGM 90Ah. Isn't a kind of leisure battery?

[mistericeman]

Never mind the difference in battery types (ANY paired batteries should be of the same capacity/type and age or you risk one battery discharging into the other... hence why wagon batteries are usually replaced in pairs)
What happens when your heater/lighting etc flatten the leisure battery over night AND in the process also the starter battery too???
Split charge or battery to battery charger system is only sensible way to ensure you can always drive onwards in the morning.

[jasonx]

I have just bought a 120Ah deep cycle battery for my Custom converted to camper to power a webasto airtop 2000 and a waeco CF35.

How about connecting the battery in parallel with the second battery, so as to benefit of both capacity? Is there any risk?

https://fordtransit.org/forum/viewtopic ... 7#p1445102 this is how I did mine