HB2 at higher Voltage.

Kabana

Member
Joined
Jul 26, 2021
Messages
15
Via a voltage booster I have built and a relay harness I will increasing the voltage up to a steady 14.8V in a HB2 headlight housing which is quite large and likely to cope with the increased heat.

I am well aware of the exponential lifespan reduction of the light bulb and the increase in light output and from my understanding 14.8v is a safe upper limit where lifespan is acceptable to me.

As I will be increasing the heat in the bulb, my question is which bulb to use? Also of note is that the last time I used high beams was closer to 10 years ago, so the high beam consideration is not a factor.

I will not be considering Longlife or vibration resistance bulbs due to their muted beam.
 

Alaric Darconville

Moderator
Staff member
Joined
Sep 2, 2001
Messages
5,256
Location
Stillwater, America
For excellent performance (but also shorter life, because the optimizations in the bulb that give you that performance will shorten the life), get the 9003NHX. Buy extras.

Be very sure your voltage booster is well-constructed. If it fails, it will plunge you into darkness. If you can make a second one so each lamp has its own, you'll have two points of failure BUT you'll have redundancy. (And if one does fail, maybe then scrap the idea of a voltage booster and just use relays).

If it has a ramp-up feature to perform a soft start (but still at 12.8 or 13.2V) and ramp to 14.8, you'll reduce shock on the filaments so you reduce the risk of the filaments going when you turn the lights on. This additional complexity can also be a failure point, so be sure what you're doing with well-chosen, well-assembled, and well-protected components.
 
Last edited:

Kabana

Member
Joined
Jul 26, 2021
Messages
15
For excellent performance (but also shorter life, because the optimizations in the bulb that give you that performance will shorten the life), get the 9003NHX. Buy extras.

Be very sure your voltage booster is well-constructed. If it fails, it will plunge you into darkness. If you can make a second one so each lamp has its own, you'll have two points of failure BUT you'll have redundancy. (And if one does fail, maybe then scrap the idea of a voltage booster and just use relays).

If it has a ramp-up feature to perform a soft start (but still at 12.8 or 13.2V) and ramp to 14.8, you'll reduce shock on the filaments so you reduce the risk of the filaments going when you turn the lights on. This additional complexity can also be a failure point, so be sure what you're doing with well-chosen, well-assembled, and well-protected components.
The NHX was going to be in my list 😉

Initially I was going to build it into the harness to limit losses, but I will be making a unit for each side which will be plugged in, so if there is a failure I can pull over and reconnect the OEM loom to the bulb/relay harness. I have been testing this for a few years with many upgrades where I have got it to be robust now and I know real world use never = test conditions.

I have seen the Trucklite? version mentioned on here with the slow ramp to extend life of the bulbs, but TBH this is a lot of extra work and as you know more failure points.

Bulb lifespan will not be a consideration as I don't use the lights much and my calculations show i will be reducing lifespan considerably but well within reason for my use.
 
Last edited:

Kabana

Member
Joined
Jul 26, 2021
Messages
15
With regard to the blue portion on the bulb like the Philips RacingVision and X-tremeVision, as I will be running higher V and creating more heat in the capsule will this be a problem or not because the the low beam is not tinted - keep in mind I will only be using the low beam.


For reference:
Racingvision GT200 1630072096521.png

Xtremevision 150 1630072157109.png
 
Last edited:

wrcsixeight

Well-known member
Joined
Nov 10, 2013
Messages
114
I make use of a lot of voltage buckers or voltage boosters, and some combo boost/buck units.

I use the buckers mostly for dimming interior LEDS or slowing ridiculously powerful computer fans to tolerable noise/ ampdraw/airflow levels.

The voltage buckers I use have XL4005 or XL4015 chipsets, and are only rated for 5 amps. There are peel and stick small finned heatsinks which can fit atop these chips and keep them much cooler wen approaching their 5 amp limit, and the only failures not induced by unintentional shorting during testing, that I have had, are from the one I did not use IPA alcohol to wipe first and the heatsink fell off.

My 150 watt V booster can fit a 50Mm or 60mm computer fan bridging the heatsinks. Mine has exceeded its rating for a good while, unintentionally. Some models have voltage potentiometers and current limiting potentiometers. The 5 amp versions with current limiting pots have proven less reliable and efficient.

The 150 watt unit comes with large heatsinks attached to the transistors, with a 'sil pad' thermally conductive electrically non conductive isolator between transistor and heatsink.
There should be a thermal grease to help conduct heat from transistor to heatsink.
Often there is none, or very little, and adding some can help keep the transistor running cooler, , making the booster/ bucker/ combo unit more reliable for longer.

I have phillips XV +130 h4S in Hella 5X7 dot's .
I carefully removed all the blue coating with a razorblade.
Taking precautions knowing the bulb is under pressure. It takes about 10 minutes per bulb, and a 70% ipa alcohol wetted Q tip seems to briefly help lubricate the blade/bulb and perhaps also soften the blue coating a bit.

I'd recommend practicing the scraping motion on a hardwood dowel of similar diameter to bulb, and scrape only in one direction, or have at it on an old blown bulb. but do protect your eyes, and realize the pressure required is not much at all.

Not much downward pressure is required, and withougtgood eye magnification one might not see the sub hair thickness of blue scraped off.

Try to avoid scraping both directions, hold the sharp new razor blade at about 89 degrees, not digging
.
I'd recommend not using the thick HD inflexible razors made for box cutters and such, but use the more flexible single edge rectangular razors.

I've got two cross country journeys on these blue removed phillips xv+`130 h4 bulbs, with ~80% of those ~40 hour drives occurring after sundown.

I assume that if My blue scrapings damaged the bulbs, they would have failed by now.

I also have the ability to manually control charge voltage with a dial on my dashboard, and a 12awg relayed harness. My bulbs rarely are allowed less than 13.4v and many of those hours they've accumulated so far, are at 14.4v.

I can dial it higher, but if I go 30 seconds at higher than 14.79 volts, my check engine light comes on.

My dial is a ten turn bourns potentiometer, and changing voltage quickly does not happen, and my eyes/brain can just barely perceive the brightness difference when I lower battery voltage from 14.7 to 13.7v, or visaversa.

Voltage reaching bulb is ~ 0.3v less than battery voltage, last I measured.
 

Kabana

Member
Joined
Jul 26, 2021
Messages
15
Thank you very much wrcsixeighty, I was expecting replies from you after seeing your previous post and from Virgil after this post on this subject before.

If I was a regular user of the high beam I might consider removing the tinting, but this won't be a factor for me.

As far as voltage goes thanks for the real life experience. I am yet to decide on the final voltage, but it will in the 14.5 - 14.8V.
 
Last edited:
Top