My DDM Tuning, single bulb 35W HID kit ($25) gave me back 20W. Nice. But when I really NEED 100% from the Gerbing and grips, I switch off headlight. Illegal in CA, but no cop has EVER bothered about it here. At night I use a "real" Heat Troller for Gerbing jacket which is more sophisticated than a typical rheostat. It's some sort of Pulse Wave controller invented by the owner of Warm & Safe (now owned by First Gear). Really saves battery as it continually switches OFF and ON. Keeps jacket fairly warm, gives Stator a chance to charge up Batt. Seems to work well. For LONG night I have to lower Gerbing down to about 75%, grips set to Low. But if doing only an hour or three ... I can run at 100%, battery OK. The HID 35W kit seems to help and puts out 3 times the light over stock 55W H-4. Plug and play, $12 replacement bulb. Going on 3 years, still working perfect.