Introduction: Rechargeable Bike Light Set With Bottle Battery
This is my light set up I've just completed for the long Scottish winters complete with high power front and real LED lights and a rechargeable bottle battery. I've drawn inspiration from a couple of people who are referenced with thanks.
Step 1: Costs
Since cost is usually prominent in folks mind I'll start there. I've tried to keep these as low as possible since i consider this a prototype and intend to have a better version for next winter.
Total for this project = $25 (£15) + £24= ~£35 plus loads of left overs for another project. Not bad for a really bright light set.
Parts From DX
1x Cree white LED $6
1x Cree red LED $4
1x 22mm tight focusing lens (pack of 5) $5
1x 25mm diffusing lens (pack of 6) $3
1x 800 ma LED driver (pack of 4) $7
1x 1 ohm 3w resistor ~20p
1x cheap water bottle (Tesco Value 500ml) £1
roll of cable £1
Water bottle £1
8x 2500 AA cells £10
inner tube £0
Expanding Foam £6
Other bits £5
Step 2: Front
First up the front light.
This uses a fairly standard plumbing end cap design there are loads flying round the web, one of my favourite ones is this, https://www.instructables.com/id/Bright_Luxeon_LED_Bike_Light. kwschofi goes into more detail around the building of the light so i'll focus on my fixing. My needs are far more modest so i've gone for a single emitter which makes fixing fairly simple.
After i wired up the emitter and epoxied it in place i epoxied the assembly to a peice of aluminium bar which i bent to a roughly 90 degree bend using my work bench and brute force.
To clamp the assembly to my handle bars i used an old lights clamp, this one had no quick release or the like which suited me. I expect to leave this attached to the bike most of the time. I'm working on the theory if it doesn't look worth stealing and its not as easy as flicking a switch it'll be left alone, wish me luck.
I took the assembly to my bike and measured it up and cut the bar to length. Drilled a hole at the back the same size as the bolt in the fitting kit and we are done.
I've used deans style connectors through out so that individual parts can be removed if needed.
Step 3: Rear
The rear light is based in part on this https://www.instructables.com/id/Ultimate-Bike-Light---FrontRear-Combo---100-Lumen. The most obvious deviation being that since my battery pack is in a water bottle i have managed to construct this entirely on a reflector.
Once i wired it up it was simply a matter of getting stuck in with the hot glue. Be careful to ensure you fill any gaps to prevent water ruining your hard work.
Step 4: Front Wiring Loom
For the electronics i've stayed simple a pp3 clip with a deans connector soldered across + and - for charging and the driver board soldered to the + lead of the pp3. The negative lead is left hanging as it will connect to the switch. From the driver you can see the out puts that connect to the emitter.
Step 5: Rear Wiring Loom
The rear is done much the same except there is a 3w 1 ohm resistor attached between the + lead of the pp3 and theout put to the emitter with the negative going to the switch.
Step 6: Bottle Part 1
Externally the bottle needs 2 thing controls for the lights and out put leads to connect to the emitters. It also needs to remain fairly water proof. I've used switches i had available they are simple push locking switches with no weather proofing so we'll have to improvise.
First i drill a couple of holes in the side to fit the switches second some in the lid for the out put leads.
Step 7: Bottle Part 2
Next we prepare the cells I've wrapped them in electrical tape to stop the foam getting between the cells. Once the the cells were connected to the wiring looms, 4 cells for the front 2 for the rear, i lowered the batteries into place and soldered up the switched.
This was a pain the arse trying to solder the switches with only a little bit of lead sticking out, word to the wise use longer cable no one is going to see it when the bottle is sealed.
I also wired up the output from the looms to a pair of deans plugs coming out from the bottle
Step 8: Bottle Part 3
Batteries in place switches soldered up its time for some weather proofing.
Take a large bit of inner tube, i got a punctured one from my friendly lbs, some hot glue and cover a nice big area around the switches this should prevent water ingress. I had to make sure the rubber wasn't too tight as it impeded the return on the switch.
Some more hot glue round the exit points of the leads and your lid should keep water out again.
Step 9: Bottle Part 4
I took some expanding foam and covered the two battery packs this physically restrains the batteries and stops them from rattling about in the bottle. This is really messy if your not careful and it'll take days or some serious file action to get off your hands.
The foam stuck to some of the components and started to fill too high and didn't coat the batteries at first so i had to scoop some out with some kitchen roll and add some more further down till it had covered the cells, held them in place and didn't coat the components.
Thanks to the folk at ice bike for the inspiration
Now its just a matter of running some leads from the bottle cage to the handle bars and seat post.
Step 10: Charger
Since the two battery packs are sealed we'll need some way of charging them. For this is took a Marks and Spencers altoids tin and used a (mostly) reference LM317 constant current out put design. For power i used a ac-dc adaptor outputting 9v enough to cover the large pack but a bit high for the smaller leading to quite a bit of heat. This isn't optimal since it will take 10 hours to charge from flat and isn't the best method of battery charging but it'll do.
Some advice on a more advanced charger would be well received.
Step 11: Action Shots
And now for some gratuitous action shots
Step 12: Design Critisims (Or What I'd Do Differnt)
A couple of changes i'd make.
I would have the out put leads come out from the bottle not the lid, i suspect continuous rotating motion will cause the solder joints to fail eventually and they'll be a right pig to fix.
Some form of battery charge meter would be nice, not sure how to implement this though.
Small waterproof switches on the handlebars would probably be more useful
The connection for the back light at the bottle, i should have used a different type of connector. The back light couldn't take the current the driver for the front outputs at the moment i have to connect the front up first since it can take the wattage out put to the rear.
Step 13: Updates
Since i wrote this I've made one of the changes in the criticisms sheet.
On a early test run the rear light dropped out after a little bit of investigation the joint from the output and the resistor failed due to the rotation stress of the lid being secured. I've moved the out put leads and re-soldered, i don't recommend the original design soldering in the bottle is a pain.