Inverter - needed?

[chin_k]

54.6 v is typical voltage for charging 48V lithium battery. Looks like they are pretty small drain on your power, with only 110 V @ 2.2A or 240W max for each of your bikes. If you do have issue with efficiency, you may consider going around the inverter by converting the 12 VDC to 54.6 V DC which is less than 120W. However, it is difficult to find a 54.6 v converter, so you probably need to get an adjustable one, and dial it to 54.6 (most converters try to stay under 48 volt, so it is a difficult to find item). With the extra panels that you have, it may not be worth your time for the improvement, and I would just do whatever you are doing right now.

[deppstein]

Thanks for this information...just another example of valuable stuff to be learned on this forum.
Since I am not having any efficiency issues (charging time and process works well for me), I agree with you that keeping things the way they are for me seems right.
David