HID draw, brightness and cooling

[cobb]

Long story short, I am legally blind and use an electric wheelchair. I need lots of light to see, therefore rigged up 2 55 watt helogen lamps in series to run off of 24 volts and added a roll bar with 4 more 55 watt lamps in a series parallel configuration for same 24 volt operation. I had purchased some 25 and 35 watt lamps, but they were blown away by the 55 watt lamps.

Here are the first set of lamps http://www.wheelchairmodifications.org/light_upgrades_01.htm
Here is the roll bar http://www.wheelchairmodifications.org/roll_bar.htm

The 2 lamps work well for in dark areas in doors and on the street. Now when it comes to bullitin boards, chaulk boards and other areas I can not see well, man the roll bar brightens things up. I had considered using HID lamps, but the few kits I saw in catalogs they seem to draw just as much power as regular lamps, plus i had to mount a highpower transformer to operate them and hate to have that by my head or near my body.

YOu guys are the experts here, has HID changed that much or do they make LED head lamps?

 

[thevirusunknown]

I can't tell you anything about HID, you'll have to look to other posters for that info. But, I can tell you that your wheelchair is AWESOME!

 

[Steelwolf]

I'm a relative newbie when it comes to HID lights, so I hope someone else with more experience will chime in soon.

I'm not sure which catalogs you have looked at, but currently, HID lamps go as low as 10W, where previously they may have been about 50W or more. You will still need a ballast (the highpower transformer), since HID lamps (the light producing part itself) needs about 300-600V to start up and about 70V to maintain the plasma ball, but ballasts are also getting more compact.

Have a look at Welch Allyn (www.walamps.com) and look for their portable Solarc products. The advantage of HID, of course, is that they are much brighter than an incandescent lamp of comparable wattage (even comparing the best xenon or halogen incandescents). I would say at least twice as bright.

There are a couple of forum members who utilise the Welch Allyn lamps and ballasts in their own homemade flashlights. They have achieved very respectable results.

Of course, you may wish to go for a lighting system with more impact resistance (HID is probably comparable to incandescents when it comes to sensitivity to impact). Then LEDs are the way to go, with the 5W LuxeonV being the most power LED you can currently get. At this power level, they are probably 20% to 50% more efficient than comparable incandescents, even including losses from an electronic regulator. Put of bunch of them together with appropriate lenses, power supply, regulator and heatsink.

You can get the Powerpuck from www.ledsupply.com to run your 5W LEDs off your wheelchair power (I'm guessing 12V battery?). The Powerpuck ensure your LEDs get the correct amount of power so you don't fry them. Your most difficult part may be building the heatsink to accommodate all the LEDs.

Hope all that information was of some help.

 

[Draco_Americanus]

I would go with HID for your aplication. I would use hella DE houseings with a normal 35 watt ballast. In my experance a DE light with the stock hella ballast draw 44 watts and throw out about 3 times the amount of light. It would take about 150 watts of quartz halogen lights to beat one 35watt HID. micro DE houseings have an insane amount of side spill but for your aplication I belive that would aid you.
I would skip on the 10 watt solarc as they take a hit in efficancy at that power. at 10 watts I belive they are rated for 530 lumens or so, A 35 watt D2S bulb is rated at 3200 lumens.
They are rare but they did make 24 volt ballasts but you might need to use the 12 volt units and if you can afford it I think 4 units would work nicely.
micro DE

I have 2 of these on My Quad along with a 3rd non hella hid center head light.

 

[cobb]

Thanks, I am looking at those links. I know as a passenger I can tell when a car has HID lamps and they really stick out and seem easier to see. My eyes tend to see blue best and believe that is why white LEDs help me see better despite they are not as bright as regular flashlights.

I did not know they made them that drew that few of amps. I was looking at a performance catalog and the set of driving lamps use a remote control to operate them and they were rated I believe around 40 watts, 15 short of the 2 I use already. It did not mention the candle power, but did say they were street legal, not that generic for off road use only.

As is, the light set does not seem to effect my range, but the roll bar does make it jerk when its rolling if I flip them on and while they are on my power meter drops a unit lower than it reads. With 2 group 24 batteries in series or 24 volts 70 amps I have a pretty good range, but charge daily.

Thanks.

 

[BB]

Neat way to solve your vision problems... But a question, there are many small(er) LCD screens and head mounted display devices now. Would you be able to use something like these devices in conjunction with a CCD video camera to help you to see in low light and other conditions? The power savings and potential improvement in flexibility of vision improvements (computer assisted contrasting/color adjustments) would seem interesting.

-Bill

 

[cobb]

I had considered a pair of video glasses, but they were not cheap. I believe they make a product with what i Have made camera wise with video glasses, its like 1400 bucks. I wouldnt mind having a pair of glasses that you can see through and only one monitor for my good eye to reduce weight and increase run time. THen use a second camera for distant viewing.

 

[nobbe]

Hi cobb,

I also would recommend a Hella DE Xenon or micro Xenon 35 Watt HID light because the amount of light those units put out is really amazing (it is true, about 3500 lumen). But I would use a configuration with a D1S bulb as this does not need a high voltage cable from the ballast to the bulb and therefore gives you more options where to mount and store all the stuff.
By the way, Xenlight produces and sells 24Volt ballasts for D2S and D1S HID bulbs 35 and 50 Watt. Also a firm in Germany called nucon GbR - nucon GbR -
has developed a microcontroller especially for those Xenlight ballasts that is able to regulate the power and light output between 25 and 35 Watt.

-Nobbe

 

[Draco_Americanus]

Will a D1S bulb fit into a micro DE housing? Also how mutch more expence is there to a D1S ? Will not beable to use a standard ballast with a D1S as well, the vast magority of the ballasts I see on ebay use D2S. If one needs a replacment that may be cause for concern.

 

[nobbe]

can´t tell yet, if a D1S will fit into a micro DE housing - but it shouldn´t be any problem as the dimensions of the actual bulb is the same than D2S - except for the directly attached igniter at the D1S socket - and this might be a problem fot the housing.

D1S should be a bit more expensive as you typically buy it complete with igniter. I have been paying around 50 EUROS for the set.

Well but all the ballasts on ebay are originally designed for automotive use and thus not very efficient - but when it comes to mobile applications with rechargeable batteries you want the most efficient ballast you can get for maximising your runtime. And thats what the Xenlight ballasts have been designed for. Have a look at the technical data and compare it to standard automotive ballasts !

Anyway, when the dimmable 35 Watt HID mountainbike light project will be ready I will post the results and the total costs of the setup ! /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif

-nobbe

 

[cmacclel]

You can get the Sylvania X1010 HID light set with remote control, Ballast, Housing ETC for only $299 directly from sylvania.com

 

[cobb]

Thanks for the info, this will require more research on my aprt as far as price is concerned and how to mount it all. If the brightness is way more than 2 halogen lamps i may be able to get by with just 2 instead of 4 lamps.

One important question that remains is, can this run off of 24 volts or be hooked in series so the 24 volts feeds the 2 lamps 12? My current lights are in series for 12 volt operation of 24 volts, the 4 lamps are in series parallel setup on one switch.

 

[BB]

I would not recommend running HID lights in series... The active ballasts are probably highly non-linear (voltage vs current) and if they are constant power devices (i.e., as input voltage falls, the input current rises-- i*v=p) they will look like "negative" resistors--and will not evenly divide the 24 volt input voltage.

If you put these in series (two 12 volt devices on 24 volt mains), they will probably oscillate and may even fail.

-Bill

 

[cobb]

Well....... That changes the playing field. I have 70 amps and 24 volts to blow, however I am limited to about 20-23 amps at 12 volts through my converter I use to drive my 12 volt accessories. Think 20-23 amps is enough to run them safely? I generally use a 3 amp cooler on my chair when in use, that is about it for the 12 volt loads.

 

[BB]

If you assume that the HID ballasts are 60-80% efficient, then you can probably assume approximately 5 amps maximum of 12 vdc per 35 watt HID.

Interestingly, if you assume that both the HID ballasts and your 24 to 12 vdc converters are only 60% efficient (not at all unusual), then it may be a wash in overall power consumption between 35 watts of HID running off of your converter (60% x 60% = 36% overall efficiency) and 97 watts of Halogen lights (2x 12 volt 50 watt lamps in series on 24 volt mains). Both setups would consume the same amount of 24 vdc battery power.

You would then be left with determining which is better for your needs... 35 watts of HID or 100 watts of Halogen--In theory, both would produce roughly the same amount of lumens. The HID would probably be whiter and more constant output (because of your converter and the HID ballasts). The Halogen would be cheaper and you could mix types (narrow driving beams vs wide fog, etc...) for differing conditions.

-Bill

 

[Draco_Americanus]

why use a converter ? just hook one ballast to one battery. I.E the left hid to battery number 1 and the right hid to battery number 2. it would waste less power then useing a down converter and since your useing about the same current (in my experance the Hella gen 3 ballats take 9 watts for a total draw of 44 watts each) the load will be for the most part ballanced between both batteries and if it's not totaly ballanced the differance would small. (maby only a few watts)
Or look at ebay for 24 volt ballasts, hella did make 24 volt gen 3 ballats and they typicaly sell for 50-80 bucks each on a good day.

 

[BB]

Not a bad idea connecting to two batteries individually for 12 vdc power... But I would suggest that you make sure that you connect an individual ground wire return wire internally to the "2nd" ballast. Normally, most automotive lights would simply use the frame ground as the return. In this case, the metal shell of the lamp assembly would be at +12 vdc and if something metal connected between the isolated lamp housing and your metal "roll bar" or the (true grounded) lamp next door--you would get a nice arc welder effect going.

Overall, the 24 vdc ballast is probably a better idea. You will want to make sure that the battery loads remain balanced (current wise-in the example of two 12 vdc lights on a 24 vdc battery system). Too much imbalance, will not be good for the batteries (unequal current use will mean cause unequal charging--leaving one battery undercharged or overcharged). Make sure that you check the water levels every few weeks or so--even if they are "sealed" lead acid batteries. You will probably drive the water levels down in the battery with the lighter loads as you will have to "overcharge" it to fully charge the other battery.

If they are gel cells (which I believe you cannot add water to), I would probably not risk an imbalanced load and early battery failure.

Also, make sure that you use appropriate fuses in all +12 and +24 vdc power wires to your lamps (something along the lines of a 15 or 20 amp fuse--maximum--for 14 gage wire). You do not want a short in your power harness directly connected to your battery mains. The risk of fire and burns would be too high without fuses (installed as close as possible to the battery mains).

-Bill

 

[Draco_Americanus]

I forgot about the second ballast's grounded case. Thanks BB!
If the micro DE lights are used, it's been my experance that the light's houseing is not connected to ground so that would not be a problem. (I have 4 of these, the D2S bulb is not electricaly connected to the housing, nor is the ballast's socket, useing a hella ballast)
One other thing about the unbalanced load, if you use new bulbs and ballasts they will "should" be very close in current(with in maby 100-200 ma) draw.
In a few days I should have 4 hella made 3rd generation ballasts and I will test this theory and find out how close they all draw current wise.

 

[cobb]

Thanks. The chair as most use sealed gel cells cause of DOT regulations. They use 24 volts from 2 12 volt bateries hooked in series. The power for the system and charger hook up to the same terminals. So, the batteries are fairly balanced, although I found the second battery in the system seems to be a few tens of a volt lower or dies first.

I am unsure of the converter, but I believe its like 83% efficient. I think it works on voltages as low as 20 volts, so it could suck my batteries dry but give me the same power.

What about HID cooling. Although I will use these off and on, I may be stationary or traveling at a blazing speed of 6mph. The halogen lamps fail every so often. I am assuming its heat buildup. The base of the lamp the metal part is discolored, blue, purple and other rainbow colors.
I also had one used as a clamp on reading light. It failed after 4 or so hours of use. I then attached some fans to the light to help blow some air on it and that seemed to fix the problem. I was going through 2 bulbs a week.

 

[Draco_Americanus]

the HID bulbs will run cooler then your halogen lights, one magor misconception people seem to have with HID is they think they will run hotter or melt a houseing...ect. one must remember they only disspate 35 watts, not 50-55 watts your other lights dissipate. I can touch my micro DE housings after an hour or more of operation, they are hot but did not burn unlike a 55watt halogen.
Thats odd your bulbs are failing that fast, you may also be over voltageing one due to an unballanced load? Also vibration can be doom for halogen and HID but I belive the HID to be more robust from my experance.