dfw

I started talking about this project in this thread. However I think this subject deserves it's own thread.

After messing around with cheap lights for a long time, I wanted a really good lighting setup. I average about 18 mph or so on my commute and I have some pretty good downhills where I can easily reach speeds of over 30 mph. Going 30 mph with crappy lights is no fun and frankly it's pretty dangerous and stupid. I needed something better.

The lights I really wanted were as good as the best that can be found on this review:

MTBR lights shootout

I read this review over and over and made a few conclusions on what makes a really great set of lights. You basically need 2 different things. First, you need a lot of light focused narrowly and intensely on a spot 40-50 ft out or so. This allows you to see what's coming as far as any obstructions or defects in the road. At 30 mph, you're going about 44 ft per second. The problem is, your eyes don't remained focused specifically on this spot all the time, so you have a problem with contrast if you only have this spot because your eyes are going between intense light and nearly complete darkness. So the second thing you need is flood to fill in the periphery. Some lights do a decent job of both with one lamp, but the best lights to me were the combination lights. One spot lamp and one flood lamp work very well together, and provided you have enough light power, form a great lighting setup.

The problem is, I'm pretty cheap. I didn't want to spend $400-900 on lights. The Edison 10 is a fantanstic light, but the MSRP is $900. I thought long and hard about building my own setup from scratch. I have a strong background in electricity and electronics, so none of it would be outside my ability. I did some research and saw some really great ideas, but it wasn't what I wanted. I wanted something that looked professional, was easy to take on and off the bike completely, and wouldn't damage or require permanent modifications to my bike. All of the fully homegrown systems I saw didn't fit those requirements.

I gave up on the homegrown system and decided to buy a better commercial setup. I decided to take a look at the Performance Bike EVO Dual system. Performance has a good return policy, so I figured what the heck. The EVO Dual is a good system. No question about it. You have a two light setup and both lights can easily be switched on and off independantly. The lamp housings, switch, and wiring are all very good. Everything can be easily taken on and off the bike. However the system had some drawbacks I didn't like. First, the system comes with two lamps which are a 10 degree 20w spot and a 10 degree 10w spot. With both lights on, you get a decent amount of light, but very little in the periphery. You also only get 1 hour max runtime with both lights on. I looked a little closer at the sytem, did some research, and found the EVO Dual is a great system to build on and with a few modifications has the ability to go from a good lighting system to a great one.

The first thing that had to be changed was at least one of the lamps. The 20w spot is great, but the 10w spot doesn't compliment it well. The good news is the system uses MR11 lamps which are available in a variety of voltages, wattages, and beam spreads. What I needed is a 20w flood in the 20-25 degree range. The original system is 6v. I looked around a bit and didn't see any MR11 6v floods which I liked. Another problem I faced was even if I could find a 6v MR11 flood, the battery would have even less runtime at 40 watts. So since I had to change the battery anyway, I decided to go with 12v MR11 bulbs. 12v MR11 bulbs are easier to find, cheaper, and there's lots more options. So I can tweak the beam patterns with different bulbs for about $3 a pop. Going from 6v to 12v is no problem because the higher the voltage, the lower the current. The wiring is designed for max current, which you will be lowering by going with 12v.

The next problem was the battery and charger. Fortunately, someone here posted a link to batteryspace.com. That site has some really nice options and I found a Battery/Charger set that I think will work great for me. Batteries are not that complicated. As long as you know your voltage, wattage, and how much run time you need, you just select the battery pack that's going to give that to you. A little overkill is fine, but frankly I wouldn't recommend getting a battery that's going to give you 3-4 times more runtime than what you need. Your expense will be greater, you're going to have to haul around more weight, and it's going to take longer to charge them. To me, 1.5 times your required runtime is just about right. The formulas are pretty easy. I needed 90 minutes of 40 watt power at 12 volts. First you figure out the amperage which is [amps = watts / voltage ]. So 40/12 = 3.3 amps. Sometimes battery capacity is listed in mAh, so you just have to multiply by 1000. So for 1.5 hours, I need at least a 4950 mAh battery. If you needed 3 hours of runtime, you would need a 10 Ah battery. I've already ordered the battery from batteryspace. My plan is to mount it inside a water bottle. I think it's going to be too big to fit through the mouth, so I'll have to cut the bottom off and slide it in that way, then use the PVC shrink material from batteryspace to seal the bottom back on and make it waterproof. If someone wanted 3 hours of runtime, this one should be able to slide right inside a standard water bottle.
Edit: An additional note on batteries. NiMh batteries are a great way to go. The performance characteristics of NiMh batteries are well suited to bike applications. One thing about it though, you should have a smart charger. Overcharging NiMh batteries will ruin them and they aren't cheap. If you buy a pack from batteryspace, just go with the charger they recommend.

If found the MR11 lamps at batteryspace too. They have 12 degree and 24 degree 20w lamps, which should be just about right. Batteryspace also has all the connectors to replace the original ones that came with the EVO Dual.

I'll keep this thread updated with my progress.

Bolo Grubb

I am interested to see how this turns out

Cyclaholic

Why didn't you go with an MR16 system instead? they throw more lumens per watt due to the better (larger) reflector.

I built my system around a 20W 12 degree beam MR16 and a 7.5Ah SLA battery. I get 3 hours run time at 80% duty cycle (too much for SLA longevity) but I only ever need 2 hours between charges so that's OK.... 30mph on a moonless night with no street lights is a piece of cake. It seems to have enough peripheral light leakage to not need a flood.

Don't forget to derate the battery based on your amp draw. For example, my 7.5 Ah SLA is rated at 900 milliamps draw, but since I draw nearly 2 amps It's really a 6Ah battery. Your battery supplier should have a derating chart (this is important with NiMH)

I'll post some pics if You're interested.

jharte

I think these systems are awesome. I've been following most of the threads for lighting systems and have seen some real ingenuity. I like the new NMHi batteries (except for the cost). I agree, if you have the money, going with the 12 has real advantages.

I'd be interested in seeing some pics if either of you have them. Thanks for your updates!

ItsJustMe

WARNING on the batteryspace HID - they recommend either the 13.2 or 14.4v pack. I bought the HID and the 14.4v pack. My light is now dead after 3 days of use.

I did some testing, and under load, the 14.4v pack delivers 15.8 volts at first, and only reaches 15v after over an hour of use. The max rated voltage on the HID light is 14.8v.

I'm currently trying to get them to replace the lamp, and remove the recommendation of using the 14.4v pack. I will probably wind up ripping a cell out of the 14.4v pack, making it a 13.2v pack.

(also, get a smart charger if you buy their packs; the included charger is crud)

I will post a followup somewhere in the commuting forum when I get a resolution (or lack thereof). Having used the HID for just 3 days, I do NOT want to go back to halogen (though I'm running my old 20W for now). HID just absolutely rocks. But a $120 lamp that lasts 3 days definitely does not rock.

DO NOT try to run the TrailTech HID off a 14.4v pack. I think it's a good light, but a bad recommendation on the 14.4v pack.

dfw

When I first bought the EVO Dual, I didn't have any ambitions of upgrading it. I would agree the MR16 lamps are better, but I don't know of any cheap dual lamp systems built around the MR16. If you know of any, it would be well worth posting some links. It sounds as if you have a single lamp MR16 light. For a single lamp setup, MR16 would be the only way to go if you wanted a halogen system. I really want a dual lamp setup to get the flood/spot coverage I feel is an advantage. MR11 should be adequate for such a setup.

dfw

HIDs are going to be much less forgiving on voltage. You can run a halogen overvoltage and only slightly decrease the bulb life. Each HID system can potentially be different because although most of the bulbs are the same, the transformers used by the manufacturer can be different. The thing about battery packs is they just figure every cell is 1.2v, so 10 cells are always rated at 12v. The problem is different battery technologies (NiMh, NiCad, etc) produce different voltages per cell. So the cumulative effects of having 10 or 12 cells can be significant. It's probably best to just stick with the battery type and number of cells that came with your original pack if you have HID, unless you are familiar enough with batteries to know how many cells you are going to need for a given battery type.

dfw

I hadn't really thought about it much. Here's the spec sheet on the batteries for the pack I'm using:

Spec Sheet

Assuming my two 40w lamps will draw 3.3 amps (I'll have to put a meter on them to be sure), I should be discharging the pack at a 0.66C rate. Going by the 0.5C discharge curve, the batteries should perform at about 4500 mAH, or perhaps just a bit less. This should give me about 82 minutes of max run time (theoretically). My commute lasts about 50 minutes, so I should be in good shape, but I'll just have to try it and see what happens.

blueeyedme

[QUOTE=dfw]My plan is to mount it inside a water bottle. I think it's going to be too big to fit through the mouth, so I'll have to cut the bottom off and slide it in that way, then use the PVC shrink material from batteryspace to seal the bottom back on and make it waterproof. If someone wanted 3 hours of runtime, this one should be able to slide right inside a standard water bottle.
QUOTE]

Why not just buy one of their waterbottle batterys like this one https://www.batteryspace.com/index.as...OD&ProdID=1251 Should work for your halagon setup, price is right and you don't have to worry about cutting a bottle apart and hoping it all fits and is waterproof.

In any event, I'm glad you posted this thread... gets me thinking about a DIY HID project. For anyone who has used the Trailtech HID, what did you use for a bar mount on your bike?

ItsJustMe

I bought a bare bulb, and followed the resellers instructions on battery pack (which I also bought from them, the recommended type). Only after it fried did I test and find that their recommended pack was over 1 volt above the maximum rated voltage for the HID ballast.

I haven't heard back from them yet. We shall see if they do the right thing and take responsibility for damaging the light by recommending the wrong battery.

ItsJustMe

BatterySpace now has a bar mount on their site.
https://www.batteryspace.com/index.as...OD&ProdID=2150

But I think mine is a bit better, it's lower profile and it sure as heck didn't cost $16.
All I needed was a chunk of 1/8" x 1" aluminum bar, wrapped around a broomstick as a form. Here's a pic:

biodiesel

I've been running a pair of EvoPro LED's that run on AA's. Theyre about as bright as my old 10w halogens. I love the battery change once a week.
Of course i'd like a bit more light. Have you thought about LED setup? The battery idea is great. Heck i'd love to run everything off of a central battery, taillights etc.

Love to see someone tinkering. Keep it up.

ItsJustMe

Heh, heh, heh:
https://www.trailtech.net/eclipse_mr16.htm

Coming this fall; MR16, 30 watt HID from TrailTech. 100 watt halogen equivalent light output.

Wow.

oboeguy

Wow indeed, and it be yours for the low, low price of $1000000000!

bbaker22

Wow is right! The current 13w offering from Trail Tech produces an amazing amount of light. More than double the light would be great for 24 hour racing. Pricing from Trail Tech is generally pretty good, too.

baker

LittleBigMan

Great idea. I agree that bicycle lighting is too often weak and sickly for the speeds I reach in the dark. The last thing I need is to suddenly notice a branch in my way going downhill.

If I've missed anything with this next comment, just disregard it: you figured your battery size (total amp/hrs) by doing the math. My experience with a different battery (sealed lead acid) showed me that the higher the watts, the less accurate the math was. You might find you need more amp/hrs than you first thought, just to prevent this effect. The smaller the battery, the more prone it is to "hit bottom" before it's projected run-time. It's better to have too many AH than not enough.

dfw

As someone else pointed out, batteries are rated at low current draws. For higher current draws typically you'll get less than the rated value. I don't know how the curves work out for lead/acid batteries, but I suspect from what you're saying there must be a more pronounced difference at a higher current draw. I stayed away from lead/acid because they are significantly heavier than newer technologies and not really all that much cheaper.

From what I've calculated on the battery I've ordered, I SHOULD be somewhere around 65-70% depletion on my battery even allowing for less capacity at the higher current draw. This is pretty much optimal as far as I'm concerned. I wouldn't want to get much more than 80%, so this leaves me with just a bit of fudge factor. I'll test the battery and lights as soon as I get them and report on the actual performance. If I find the battery performs at much less than my expectations, I will buy another just like it (for around $35 I think) and run it in parallel with the first one. This will double the capacity. I think I can fit two of these batteries in a 33 oz water bottle.

dfw

I looked at the battery you mentioned, but it wasn't exactly what I was looking for. It has the same Ah rating as the battery I bought, however it's 13.2v verses the 12v battery I bought. This means the light will be brighter, but the battery will run down faster due to higher current. Another reason was cost. Had I bought that battery, I would have had to spend another $35 on a smart charger. That battery comes with a dumb charger which means it will take much longer to charge and you run the risk of ruining the battery by overcharging (although given the slow charge rate this risk is low). For about the same price, I bought a battery that better suits my needs that comes with a smart charger. I have plenty of old water bottles I can use.

oboeguy

Hey dfw how about you take some pics as you're putting this thing together and make a little write-up for us? I know I'd read it through!

dfw

It took a while for batteryspace to ship all the parts, but I finally got them today. The lamps they sent were just a tad taller than the originals. One of the lamps just barely fit inside the housing. The fit is acceptable, but another source for the lamps might not be a bad idea if you didn't want to take the chance of them not fitting.

I put a fast charge on the battery and gave the lights a test. The lights ran for 72 minutes before the light started to fade. I was hoping for 82 minutes, but my commute is less than 1 hour, so I'm still in good shape. I really like the charger. It has two different charge rate settings which are .9A and 1.8A. This is pretty handy because it takes about 2 hours on the 1.8A setting. If you're leaving it overnight, you can put it on the .9A setting. Slower charging is easier on the battery. The charger shuts down to a trickle charge once the battery is full, so you can leave it on overnight using either setting. The battery has a charging port which provides thermal shutdown for added protection. With both lamps running, I read 3.3A on my meter, which is exactly what I anticipated. I'm going to charge the batteries overnight and try another test.

I've only looked at the light indoors, but it seems to be exactly what I wanted. You can really tell the difference between the spot and the flood and both complement each other well. I'm very interested in finding out how they perform on the bike.

steveknight

I have played around with light setups (homemade) different wattages overvolting and mr11 and mr16 bulbs.
the mr16's really do put out more light per watt and there are some great bulbs for them. https://www.bulbsource.net/soluxpricer.htm the 4100k 10 degree bulb is a killer thing. it eats up the power but it is the brigthest bulb out there. I used the 17 degree and it lights 3 lanes up brighter then most bulbs did noe lane.
ovevolting a halogn will give you more light per watt then a bigger bulb.
I use one of these https://www.cs.indiana.edu/~willie/lvr.html#anchor0005 to control the overvolting.

Scott 1957

What type of battery and charger did you buy. Where did you buy it?

Thanks