Talkswindon

Coffee Talk & What's On => Coffee Talk & New Member Introductions movement => Topic started by: ddrooster on January 30, 2015, 03:06:30 PM

Title: Hi im new and interested in green alternative lifestyle stuff
Post by: ddrooster on January 30, 2015, 03:06:30 PM
Hi  im Dave
I am interested in  lots and lots of green and alternative  energy  stuff
the big project is at the moment  to build a robust touring bike  from donations  theres a guy called tTOm who issued a challenge to put one together for less than £25
well I hope to beat it 
so any donations  readily accepted 
so far  I have  my cooking equipment  stove ,pan , knife , fork spoon etc all for free 
my sleeping  mat  therma rest from the  1990s  and sleeping bag
everthing else  well here we go
I need a bike  with sensible gearing  steel frame  unless im lucky  racks panniers  I have a waterproof rucksack
so please give whatever you can
what do you get in return
well im an engineer  im working on  cheap  lighting sources   for use in situations like  no mains electricity
if it works on a bike it will work in a 3rd world country
this has to be low cost  ( cree make  1000 lumens torch  for  £5 add a battery and a solar charger  its less than a tenner   and you can read \ work by it for a few hrs  it just needs refining
anyway over to you
I am more than willing to help imn anyway I can on projects tech advice
regards and thanks for reading
dave
Title: Re: Hi im new and interested in green alternative lifestyle stuff
Post by: Geoff Reid on January 30, 2015, 11:25:17 PM
Hi  im Dave
I am interested in  lots and lots of green and alternative  energy  stuff
the big project is at the moment  to build a robust touring bike  from donations  theres a guy called tTOm who issued a challenge to put one together for less than £25
well I hope to beat it 
so any donations  readily accepted 
so far  I have  my cooking equipment  stove ,pan , knife , fork spoon etc all for free 
my sleeping  mat  therma rest from the  1990s  and sleeping bag
everthing else  well here we go
I need a bike  with sensible gearing  steel frame  unless im lucky  racks panniers  I have a waterproof rucksack
so please give whatever you can
what do you get in return
well im an engineer  im working on  cheap  lighting sources   for use in situations like  no mains electricity
if it works on a bike it will work in a 3rd world country
this has to be low cost  ( cree make  1000 lumens torch  for  £5 add a battery and a solar charger  its less than a tenner   and you can read \ work by it for a few hrs  it just needs refining
anyway over to you
I am more than willing to help imn anyway I can on projects tech advice
regards and thanks for reading
dave

Hi Dave, welcome to TS :)

I'll be interested to hear how you get on with the Cree & PV recharging.  My experience with Cree stuff is that the manufacturers are a tad, erm, optimistic with their claims of 'x' hrs runtime for a 'n' mah lithium batteries. 

Roughly speaking I've found that my Cree's perform at roughly 60% of manufacturers claims.  Currently I'm using a pair of CREE XM-L/L2 led's which do chuck out a useful level of light, a claimed 1,000 lumens per bulb.

I haven't done a total runtime test but I like to get a whole weeks worth of commuting in without recharging batteries so I knocked up a battery pack containing 7 x 1.2 volt 2,900 mAH batteries which gives me 8.4v and just over 20,000 mAH.  Bulky, but effective.   

I have no idea how long an 8,800 mAH battery pack, or even a single 18650 battery would take to charge via a solar panel so I'm hoping you'll be able to educate us on that point :)

I used a pair of 7 watt 250 lumen cree's for a while but quickly found that the 3xAAA batteries didn't last long enough so, (no surprise here!), I knocked up a larger capacity battery pack.  The 250 lumen ones have a fairly wide voltage tolerance, I fed them 3.6 to 4.8 volts without complaint or much difference in output.

My 1,000 lumen Cree's are really good but pull a (claimed) hefty 2.8 amps.  They're not as voltage tolerant as their dimmer brethren. Mine won't operate at >8.5 volts and shut down at < 7 volts.  Manufacturers claim a range of 5.5v to 8.4

The 250 lumen ones are more than adequate for being visible to other road users and seeing where you're going.  They'll probably be a better option for off-grid recharging but I freely admit that I'm not yet familiar with the pv options.  I'd like to know because I also need to knock up some low voltage lighting for our increasingly regular camping trips.