DIY Battery & Charger help

[toonarmy20]

HI, I am after some help with a project i am planning.
I travel a small distance to work but am almost daily having near misses with cars, they must just not see me!!!!

I have ordered some 3w LED 4AAA torches from hong kong off Ebay. I dont need a great deal of distance but wouls lke them to be bright!
I have also got some 5 mode drivers from tinygreensheep.com.
I plan to link the three lights to one switch and mount them on my handlebars. I dont see this part being too difficult!

In the future i plan to get 3 RC motor heatsinks and some copper pipe end caps to create a 3 LEDlamp similar to one posted on MTBR.com (http://forums.mtbr.com/showthread.php?t=552475). i will use the flashlights/torches as parts for the new lights or i might splash out and get some new stuff!

The part i have not been able to understand is the external battery and charger part. I want to mount a thin tube behind my rear down tube attached to the bottle cage lugs to hold the batteries.

How to i make an external rechargable battery pack?
what parts do i need? where is the best (cheapest) place to get them?
can i DIY one using laptop battery cells? which charger would i use?

any help ill be greatly recieved!

thanks Rob

 

[Christexan]

Honestly your best bet for pack is just buying a complete charger/pack set, yes, you CAN DIY with appropriate cells (laptop pack, for instance), BUT you'll need some additional stuff to be safe...

Battery charger

Battery cells (from a laptop pack, usually joined with metal strips, keep those strips attached (cut between cells) and use them to solder to instead of directly on the cells)
Safety protection circuit PCB
Shrinkwrap
Heatgun
Solder and soldering iron
Wire
Connector(s)
Voltmeter/multimeter
some method to mount the pack to the frame (fabric case, velcro straps, etc)....
Time and patience to assemble

OR... spend about $55 (probably $10 more than DIY), and get a nicely custom made pack, using fresh brand new cells of "known" quality, and a matching charger with connections which you need anyhow. Just add matching (tamiya in the sample below) connectors to your light source and a pouch or strap to match the pack to your bike (you can also get "water bottle-style batteries to go IN the cage if you aren't using it) you are good to go, for around $60 total, and a few minutes assembly.

One sample site:
http://www.all-battery.com/packandchargerkits.aspx

 

[toonarmy20]

thanks, this the king of thing i am looing for,
are 2 cells enough?
how long (rough guess!!) would they power a 3w LED? non specific LED!

thanks for the help and the link

Cheers

 

[yellow]

regular town driving = dynamo light
... the ONLY way that it will work for sure, battery lights are prone to fail in such application

(as there are no good dnamo lights - that give a good value to their cost - available, You would have to build one for Yourself.
Good, if You wanted to build, so it does not matter that its not battery powered)

 

[herulach]

regular town driving = dynamo light
... the ONLY way that it will work for sure, battery lights are prone to fail in such application

(as there are no good dnamo lights - that give a good value to their cost - available, You would have to build one for Yourself.
Good, if You wanted to build, so it does not matter that its not battery powered)

I'd be hard guessed to believe they're 'prone' to failure. I've used battery powered lights for the last 7 years, and am yet to have one fail on me, when it did it was only a case of shoddy soldering on my part.

 

[yellow]

I thought more in the direction of care (for the batteries)

For my town bike - placed somewhere in the bike room for much time - I know:
no daylight? --> Dynamo on and everything goes

thats not an application like the Nightride I just came back. One use, known a few hours in advance, no problem to care for batts.
But for general and seldom use, or for constant use as well, batteries seem to need more "work", than I want to put into them