Hi guys, just thinking of starting this project, I have two 6000k H1 lamp and ballast not being used and thinking of modding it (just for fun) to be fitted on my mtb. I'm wondering what kind of power source should I consider, a car battery is definitely out because of the size, I'm wondering if 4x 18650 would be able to run it. Tried 4 x 16340 and it didn't work. The bulb and ballast are tested to work with my spare 12v car battery. Also, they're 35W.
Need Help : Wnat to MOD Car HID for bike.
- Thread starter nizesa
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My assumption is using P=IV
power, 35W=I(14.4)
hence current, I = 2.43Amps
assuming i get 2000mAH out of the 18650, total Amps would be 4 x 2000mAh = 8Ah.
Based on that, my runtime will be 8Ah/2.43A = 3.3 hours
Assuming 1/3 efficiency = 1 hour runtime.
Are my assumptions/calculations right and will?
WIll the battery be able to draw out the amps needed?
power, 35W=I(14.4)
hence current, I = 2.43Amps
assuming i get 2000mAH out of the 18650, total Amps would be 4 x 2000mAh = 8Ah.
Based on that, my runtime will be 8Ah/2.43A = 3.3 hours
Assuming 1/3 efficiency = 1 hour runtime.
Are my assumptions/calculations right and will?
WIll the battery be able to draw out the amps needed?
I think the 35W refers to the output power. If efficiency is 80% it will draw about 3A which is 1.5C. You will get less than an hour of runtime. Ok, probably more than a trip around the block but probably not long enough for a decent trail ride. Probably better off with 8x18650's.
Here's a link to a few 14.8V Li-ion packs in various capacities.
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=898
Typically they weigh about 13oz
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=898
Typically they weigh about 13oz
The pack is probably around 150mm long and 40mm high. I just weighed it and it's 377g as pictured.
By the way I am not putting this forward as an example of quality workmanship. The way I have put this together might not be the best way..
blackdragonx1186
Newly Enlightened
do you have a weight limit? i know where to get a sla 12v 18AH (and there are smaller ones) that weighs about 15 lbs. about the weight of a couple quality U-locks. the 18AH is only 35+ship.....
http://www.remybattery.com/Departme...y-Lighting-Batteries/Universal-Batteries.aspx
unfortunately, that part of the site is down, figures, lol. the model im talking about is UB12180. a simple google search will pull up other sites with info.
http://www.remybattery.com/Departme...y-Lighting-Batteries/Universal-Batteries.aspx
unfortunately, that part of the site is down, figures, lol. the model im talking about is UB12180. a simple google search will pull up other sites with info.
I think 15lbs is a tad to heavy (50% of the weight of my bike) + I have no idea where to put it. The 8x186500 might just do it. Als, I see battery space have a nice charger for it as well.
Thank you guys. Will probably get to it in couple of weeks when the battery arrives.
Keep any suggestions/advices coming please
Thank you guys. Will probably get to it in couple of weeks when the battery arrives.
Keep any suggestions/advices coming please
I take it blackdragon isn't a rider..
Just giving ya a hard time about the weight dragon. I know that you were being cool and just trying to help.
I wired in some balance taps to a JST-XH plug and bought a balance charger from DX
http://www.dealextreme.com/details.dx/sku.12618
blackdragonx1186
Newly Enlightened
I take it blackdragon isn't a rider..
Just giving ya a hard time about the weight dragon. I know that you were being cool and just trying to help.
lol no worries! i used to ride, until i got my license:nana:
my bike is about 50 lbs, even tho its alu mixed with something else. (mongoose walmart bike...)
the battery is actually 12.9 lbs, and imo, thats not much for me. im used to the weight of my bike, so that little bit extra wouldnt bother me. my U-lock is about 6 or so, and when i take it off, i dont even notice. like i said, they have smaller sla's as well. i was just trying to get as much AH for a good long runtime.
Your assumptions are not correct.
The ballast is often rated at 3.2A @ 13.2V, or 42W at that voltage.
4 2000mAh batteries connected in series will have 2000mAh total too, but 4 times the voltage. (In paralell you gett 8000mAh but still 3.6V or what each cell has.)
Yeah, and it's also not only the weight but the energy density available in the different chemistries. SLA has a very low energy density while li-ion is very high. If the difference in cost was astronomical then considering a small SLA might make sense, like it did in 1990, but these days li-ion is very reasonably priced, as you can see.
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