170 Vdc, 3A/1A/250mA cc supply

[dcoig1]

I'm trying to build a charger like this: http://99mpg.com/Data/resources/downloads/gridchargerstuff/dual_stage_grid_charger1.pdf

but... i would prefer to build the supply as a single unit and not use so many separate 48v supplies, add a higher 3a initial charge, and adjust the trickle current to 250mA instead of 350mA.

The charger is for a honda insight nimh 144v battery pack which charges fully to ~170v.  There are 120 1.2v nom 6.5ah 'd' cells in series. 

I am an electrician not an engineer so putting the charger together as prescribed is tempting, but something in me says there is a better way.   

The goal is to top off the pack occasionally since the factory bms never charges the pack beyond 80%.  I can use either 110 or 220v.  I would like to keep as efficient as possible, but it is not a daily charger.

I need some help rectifying the situation, please help, all is appreciated!