For L3 charging, the power put out by the external L3 charger determines the maximum available charge rate.
The HD LW has a larger battery than my SS9, but nothing near twice the size. The HD LW takes exacty twice as long to charge on the same CCS charger as my SS9. Why?
-Don- Reno, NV
It can be confusing, but if you look at what I wrote I tried to be consistent with the following:
The power grid has AC power. The batteries need DC to charge. Something has to perform that conversion and the device that does that is called a "charger".
For L2 charging, the L2 plug delivers AC directly from the grid (the station has some electronics to measure how much you are drawing, but they don't convert the power in any way) and your EV needs to have a "charger" on board to do the conversion to DC. Those on board chargers tend to be pretty weak in the grand scheme of things and so your vehicle's charger will be the primary thing that limits your charging speed for L2.
For L3 charging, the L3 stations have chargers built into them that do the AC->DC conversion and the L3 plug delivers DC directly to the vehicle. The vehicle's on board charger at that point is not needed and is bypassed when using an L3 charger. Thus, the relatively weak charger on the vehicle cannot be a factor that hinders your charge rate for L3/CCS.
My first comment above was trying to correct your statement that implied that the LW will charge slower because it has a smaller on board charger. That reason can't be correct, but that doesn't mean that it will charge as fast - just that you got the reason for it wrong.
Now regardless of who does the conversion from AC to DC, there are still wires involved and those wires have a maximum capacity. It's a lot easier to use bigger wires to get a really healthy power handling capbility than it is to include a higher power charger to convert more AC to DC, but that's up to the manufacturer. You also need circuitry to manage that power. The circuitry that directs the power is a lot simpler than the circuits in the charger to convert the power so typically those also can handle quite a bit more power. Finally, different battery cells may be designed to handle power at higher or lower rates and different manufacturers may be more or less conservative in how much they want to push the batteries and so self-imposed limits can get involved as well. There will be some costs involved in making use of more power from an L3 plug, but they are quite a bit lower than the costs in using more power from an L2 plug, and again - the size of the on board charger is not relevant for L3.
Now AFAIK, the LW hasn't shipped yet, so we are really comparing their marketing numbers to a mix of Energica's marketing numbers and some first hand accounts of charging them in the real world. From the marketing numbers, the numbers quoted from Harley are quite a bit more conservative. That could be because their marketing department under-reports. It could be because they didn't want to spend any more on bigger wires or the circuitry that directs the DC power. It could be because they want their batteries to last a really long time because that meets their image better. It can be a lot of things (including being wrong because we haven't verified it yet), but one thing we know is that it will have nothing to do with the size of the charger they built into the bike - because that charger won't be involved in L3/CCS charging. Time will tell if they are as comparatively slow as their marketing numbers suggest, but we can see that the Energica numbers on their web site are just impossible unless one or more of them is wrong so clearly marketing numbers are worth their weight in BS.
You also made a comment about battery sizes working against you and, generally, that is incorrect as well. A larger battery can help take in power faster, but it can never hurt how much charge you can accept. It might mean your percentage gauge goes up more slowly, but that is a subjective concern and has no real world impact. The MPH speed of the charge can only be the same or higher with a bigger battery, never lower. Actually, there is one way it can hurt and that is due to weighing more and making the value of the power you are taking in less because the vehicle is less efficient, but that effect is pretty minor compared to the ability to ingest power faster if the rest of the circuitry is up to snuff.
Teslas are a good example of the effect of battery size on charging. Within a model line the larger batteries will charge at generally the same MPH on L2 charging because they are all limited by the on-board charger. The only variation there is that the bigger battery is heavier and so the MPH has a minor impact. On a supercharger, though, the larger battery will tend to charge at a much higher MPH because they are limited by how fast the batteries can take charge and the more they have, the faster they can push it in. If 200 cells can accept 200X in power, then 400 cells can accept 400X, etc.
