Hi, Haven't posted for a while, been busy here, but just a note that is a bit interesting. I remember that CFL bulbs for 48V systems off of the shelf used to be quite pricey. I have discovered that the CREE LED bulbs sold at Home Depot in the U.S. seem to work quite well off of a nominal 48V bank. Haven't opened one up to check the guts and see the actual mechanism or if any parts are being run over spec. I also have not measured the light output vs. power consumption, but if there is nothing too outrageous there it seems that it might be a rather convenient off the shelf lighting option for such a bank.
Keep having fun, Rich