Battery Charging on a Bicycle

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

The reason they use NiCd on cheap LED solar lawn lights is that the sun
doesn't supply enough energy to charge a higher capacity NiMH. So in
a day you'd get about one small LED's worth of night illumination, if
you had the bike outside all day. For the same amount of solar panel,
of course.
--
Ron Hardin
[email hidden]

On the internet, nobody knows you're a jerk.

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

Wheel/rim and/or hub generators have been around for decades I believe.

ddog said:

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

Wheel/rim and/or hub generators have been around for decades I believe.

What I mean is does anyone use them to charge batteries, like for cell
phones?

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

I've seen both methods used by touring cyclists. The solar approach
requires a good-sized panel to recharge decent capacity NiMH cells.
If you a have a rear rack/panniers and can put a sizable panel across
the top then it can work ok - at least in areas where you're likely to
get lots of sunshine. Generators can also work, but AFAIK, none of
them will do so off-the-shelf. They're AC devices which works fine
for running incandescent lights, but to charge batteries you need a
stable source of DC. So you need to rectify the output with a diode
bridge and regulate the output voltage. Not hard to do, but does
require some custom wiring and assembly of appropriate electronic
components.

I just carry a small charger and enough cells to last until I get to a
campground/motel/restaurant that'll let me plug it in long enough to
recharge them. Worst case I switch to using disposable alkaline AAs
for awhile.

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

"I used to have a Dynohub on a tandem, and the bulb consumption was
unacceptable. I solved the problem (and some others) by running the
Dyno's output through a full-wave bridge rectifier and then hooking
the DC in parallel with a 6 volt (5 x 1.2v cell) nickel cadmium
battery. This not only provided light when I was stopped, the Dyno
would re-charge the nicads, and, when we went so fast that the voltage
rose above 6 volts, the low internal resistance of the nicads sucked
up the excess, gaining a bit of extra charge and saving the bulb.

The rectified output of the Dynohub was always connected to the
lights. There was no way to turn the light off while you were in
motion. It would have been easy enough to rig a switch for that
purpose, but I didn't see the need. The Dynohub has _very_ low drag.

I had a three way switch connecting the battery pack to the lights. In
the "night" position, the nicads were in parallel with the rectified
output of the Dynohub, as described above.

In the "day" position, the nicads were connected to the lights and
Dyno through a diode (rectifier). This would allow the Dyno to charge
the battery when it was going fast enough, but would not pass
electricity the other way, so that the battery would not drain running
the lights.

The "park" position completely disconnected the battery, because
diodes are not perfect, and there is a slight drain that would
discharge the nicads over a period of time.

Dynohubs are suitable for this type of set up because they do not use
the bicycle frame as a ground. If you use a full-wave rectifier, you
must keep the AC circuit seperated from the DC circuit. Since most
bicycle generator setups are made to use the frame as one of the wires
in the circuit, this is a problem. To use full-wave rectification,
either the generator or the lamps must be kept insulated from the
frame. Dynohubs are already insulated from the frame, that is why they
have two screw terminals and use twin-lead wiring."

Quoted message said:

From http://www.sheldonbrown.com/dynohubs.html

- Frank Krygowski

I cycled across Australia in 1982 with a solar panel in the map pocket of my
handlebar bag. I used it to charge the 6v gel cell that ran my lights and 6v
fluoro camping lantern. Worked ok. The panel supplied about 0.5A in full
sun.

Nick

"Pilgrim" <[email hidden]> wrote in message
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Quoted message said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

Nick Payne said:

I cycled across Australia in 1982 with a solar panel in the map pocket of my
handlebar bag. I used it to charge the 6v gel cell that ran my lights and 6v
fluoro camping lantern. Worked ok. The panel supplied about 0.5A in full
sun.

Nick

"Pilgrim" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

hi, I believe these may already be available

http://www.bikeiowa.com/asp/features/featuresdisplay.asp?articleid=658

dan

"Nick Payne" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I cycled across Australia in 1982 with a solar panel in the map pocket of
my handlebar bag. I used it to charge the 6v gel cell that ran my lights
and 6v fluoro camping lantern. Worked ok. The panel supplied about 0.5A in
full sun.

Nick

"Pilgrim" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

I used a solar panel on a 500 mile tour last summer as supplement. I found
that the panel replaced the gps power use and left the battery full for
night light. see this page; http://www.billcotton.com/quest_on_bicycle.htm

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

These guys have a lot of detail on their setup

http://www.mark-ju.net/bike_ride/equipment/electronics.htm

Pilgrim said:

Has anyone ever seen a bike rigged with either a generator, or solar
powered battery charger?

Well, I found some solar powered lights here: www.treboona.com, but
this is probably not what you had in mind?!