ermie571 wrote:I was more concerned about the not charging properly issue.
It's the same issue, just a different symptom.
Voltage - "electric pressure" - gets lost through all the poor connections, just as water pressure gets lost by leaking through poor connections. Improving those connections, and reducing that voltage drop, is why your starting's already improved and - if you were measuring the charging voltage at the battery - why I'd expect your 13.8v is now north of that, and probably nearer what it'd be if you measured it at the alternator.
Putting a higher voltage VR on will put more out the alternator, so will give you more at the other end, but you'll still be losing some in the middle. Just as turning the tap on a leaky hose will get more out the other end, but you'll still lose some on the way. Fixing the holes in the hose means you don't need to turn the tap up, to get more out the other end.
The starter and alternator use pretty much the same connections...
Battery +ve -> Big thick +ve cable -> Starter -> Alternator.
Battery -ve -> Main earth cable -> Body -> Engine/box earth cable -> Starter/Alternator.