We have 450ah victron smart lithium and during fault testing have run the bow thruster on our a54 with engine off. Voltage stays well above 24v so amperage is not spiking as it would with lead acid. 

The wind lass draws much less wattage and more than once have used it with engine off to shorten scope when our desired 7:1 swings a bit close to the neighbors. 

This is all with a set of batteries that have been used for 2 years full time live aboard and cycled over 100 thousand amp hours total. 

So my experience is that, yes , the high amp problem will be solved. 



--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com