WARNING regarding TrailTech HID.

FIRST: The TrailTech HID is a GREAT light. I have no problem with the light itself. Just to make that clear up front. It's a sweet lamp and the company is outstanding.

HOWEVER, I bought mine from BatterySpace.com, and they recommended the 14.4v NiMH battery as being "perfect" for the DIY HID lamp. So that's what I went with.

My HID lasted 3 hours before dying. Since I hadn't installed it for 6 weeks after buying it, BatterySpace wouldn't fix it (30 day warranty). TrailTech stepped up though and fixed it for free. Yay!

Turns out the problem is that the light (ballast) was fried due to overvoltage. The 14.4v battery that BatterySpace recommends delivers in excess of 14.8v for over an hour on a full charge at the load of the HID lamp. 14.8v is the maximum voltage that TrailTech says the HID will take without damage.

Normally their On/Off switch has a regulator in it that keeps the lamp from getting too much voltage. But if you buy just the raw lamp and hook it directly to power, there's no protection.

So, a warning; if you buy the raw lamp, buy a 12v or 13.2v pack, NOT the 14.4v. Either that or use a voltage regulator.

I am going to use a voltage regulator, but you probably don't want to use a conventional (linear) one; they have a lot of inherent loss. I'll be using a zero-overhead switching regulator, so the loss will be just one or two milliamps.

I hope this helps someone keep from frying their light.