Thanks for that file Colly. It helped me fill in some gaps regarding use of a continuous solenoid. Has been working well. Cheers G.I'm not sure whether you mean 'portable solar panels' to use when you are stationery/camping or a 'fixed vehicle mounted solar panel' and trying to use that to boost your charging when travelling?
From my experience you'll have no problems, if using portable solar panels to charge the aux battery when camping.
If thinking about a vehicle mounted solar panel and trying to use it in tandem with the vehicle alternator charging to fast track/boost charging of the aux battery, my thoughts are, "why bother?" If you have adequate size wiring from the vehicle battery to the aux battery, adding solar to the mix whilst driving is a waste of effort/resources (the vehicle alternator charges adequately/fast).
If a vehicle mounted solar panel (e.g. on the roof rack), I'd do it with an on/off switch incorporated. So switch to 'solar on' when stationery/vehicle engine off, to add solar charge to the batteries; switch it to 'solar off' when driving and let the vehicle alternator do the charging.
Check this link out, which may add some useful information