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Powering my home made lights


By Stuart M - Posted on 26 September 2006

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

OK so I have chosen the lights I want to use for my home made bike lights, MR16 12V leds, now just to power them. Remember I want something light weight, I wanted the light and battery mounted on my helmet, and now it obviously needs to be 12volt. Wanting to keep my money as local as possible I started searching the electronics suppliers around my area for what I was after. The handle bar light is only 1.4 watt, 12 volt, to get burn time of around 4 hrs plus some reserve I only needed about a 1 Ah battery. The helmet light was 3 watt and therefore required a little more juice, something between 2 and 2.5Ah should do the trick.

To my surprise I couldn’t find any ready made battery packs at my local suppliers that fit this bill, yes they had SLA batteries but I thought these were getting too heavy for what I wanted. My local hobby shop had some Li-ion and Li-polymer batteries but these were only 11.2v and I didn’t like the sounds of all the warnings that came with charging and discharging these batteries. Apparently they have a tendency to explode or catch fire, nt a good look on my helmet!! Could get single Ni-Cd and Ni-MH cells but at around $6 each, the battery pack was going to cost around $60 plus GST each. This would have pushed the price up to the point where ready made lights were becoming economical. I should also note this was the cheapest price I found, including Google searching Aussie sites, and was quoted as much as $100.

What to do? I followed Craig’s link on our site to Batteryspace and soon found exactly what I was after. I chose the 12v 1100mAh NiMh 2/3 A batteries for the handle bar:

http://www.batteryspace.com/index.asp?PageAction...

These fit perfectly inside the 50mm pvc pipe I was using as the housing. I also got the NiMH Battery Pack: 12 V 2000mAh (10xAA) for my helmet light:

http://www.batteryspace.com/index.asp?PageAction...

Slightly bigger but still light enough to be helmet mounted. Chose the Universal smart charger to power them up:

http://www.batteryspace.com/index.asp?PageAction...

Looking good so far, everything I want and still under $60US, far cheaper than here. Even They even had waterproof switches, something I had searched here for to no avail, promptly added these to the order. The real sting in the tail here though is the shipping cost. An order of about $65 US soon became $130 US with shipping. Much to my delight the goods arrived a day after their scheduled delivery. A call to UPS Sydney and an e-mail to Batteryspace soon had the full delivery cost refunded, now I’m smiling ear to ear.

So how did they perform? Well it really is hard to get excited about batteries but I have to say these did everything I wanted and more. The larger battery is still light enough that I have kept my helmet light, including battery and helmet, under 1kilo. Burn time is exceptional. In a perfect theoretical world I should have only got about 8.5 hrs burn time, way more than I should ever need on the trail, but then again you shouldn’t get theoretical performance in the real world. Obviously no sign of the light dimming on the night rides I have done so far, up to about 2.5 hrs so I decided to bench test it the other day. Over 2 hrs on the trail with Rob on Thursday night. Turned them on Friday morning with no additional charge and to my amazement I got over 7 hrs more burn time before the light was noticeably dimmer. It went for close to another two hours before I decided to turn it off as the light produced was not adequate for the intended use. Haven’t bench tested the smaller batteries yet but I see no reason why these won’t perform equally as well. The charger is great, set and forget, no chance of killing any batteries here which I normally do. Two charge rates for the different batteries, and very quick. Again the switches are better than expected, perfect for the task at hand.

I obviously had troubles dealing with them initially (look here) but I have to put this down to me not reading there terms and conditions properly. Happy to recommend this supplier if you are after batteries, etc of any sort. Now all they have to do is work on their delivery costs and stop processing overseas cards at time of order and I’d give them 10 / 10.

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