For my DIY HID Li-Ion, the real problem has become the switch. I wouldn't want to run an expensive light off an expensive battery without something to tell me that the voltage has dropped so low that it will damage both.

Am I wrong to insist on a switch with a low-battery indicator? If not, have any of you seen one available?

Adding a voltage meter seems awkward. Alwier suggested PART#HCAP0331
from this site, but it just gows from 11V to 13V. If I used it, would I just turn the loght off when there were only 11V? When there is less than 11V?

Thanks to all.