I currently have a victron 12 12 18amp dc-dc charger and I found out whilst on a trip to Scotland in November, this wasn't enough to keep my leisure batteries charged which at the moment is 2 120 ah giving me 240ah. I want to add the 12 12 30amp to this so I will have 48amp's but I'm also upgrading my lithium batteries to a 560ah battery. I also have a 340watt solar panel but in winter doesn't do much. So my question is will the standard alternator be good enough or would it need to be changed for a higher out put one.