[RE-wrenches] would this work?

[frank -bz products]

2 more cents worth. If your MPP control is powered by both the battery 
and PV source (diode orred) you should be able to pump solar direct. 
Several of our customers do this even though we do not specify the 
feature. You also get great locked rotor start current. The LCB line we 
made for Windy some years ago was based on this. Again not a specified 
feature.