54F100,
wa8yxm actually gave you the best answer for the information given. What you have not disclosed is what your house bank is.....
There are many more things that effect charging rate than just the converter rating.
If your House Bank is about 200AH, then a 45 amp converter is about right. That is if the converter is very near to the bank. If you don't dry camp much, it really does not matter. Don't even bother to upgrade to the 70.
If your House Bank is larger - Like 400Ah - and you do dry camp a lot, then the 70 might be worth the extra cost. Even still, if your line loss to the bank is much, there is nothing that will help that.
I used to go through this with boat owners all the time before the depression shut us down.
Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.