Alternative power source for bicycle headlight and rear ligh

[Mint]

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
Andy

 

[Rich Grise]

Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Depending on the Vf of the LEDs, you could probably wire them in series
on the appx. 6V, with an appropriate series resistor. Of course, check
each lamp for a resistor in the circuit when you hack them. ;-)

Cheers!
Rich

 

[Jamie]

Aidan Grey wrote:

On Sun, 7 Nov 2010 15:48:22 -0800 (PST), Mint wrote:


I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
Andy



Why not use rechargeable batteries?


Aidan



sure and while you're at it, why not put a generator on one of the

wheels? Too recharge it!

 

[Aidan Grey]

On Sun, 7 Nov 2010 15:48:22 -0800 (PST), Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
Andy

Why not use rechargeable batteries?


Aidan

 

[Jon]

"Rich Grise" <richg@example.net.invalid> wrote in message
news:ib7ebo$t2f$1@news.eternal-september.org...

Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Depending on the Vf of the LEDs, you could probably wire them in series
on the appx. 6V, with an appropriate series resistor. Of course, check
each lamp for a resistor in the circuit when you hack them. ;-)

Cheers!
Rich

The lamps are already running on 6 volts...simply connect them in parallel
to a 6
volt source such as a lantern battery...it has plenty of capacity for a long
run time.
This will eliminate the low capacity AA cells.

You might consider a blocking oscillator design which you could house in the
battery box. There are many examples on the web.




--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[JeffM]

Jon wrote:

simply connect them in parallel

Wiring LEDs in parallel is almost never a good idea.

Searching this group's archive for *current hogging*
could be instructive.
As has been mentioned,
a series configuration is generally preferable with LEDs.

As has been mentioned,
figuring out what presently limits the current would be a good plan.

 

[Rich Grise]

JeffM wrote:

Jon wrote:
simply connect them in parallel

Wiring LEDs in parallel is almost never a good idea.
Searching this group's archive for *current hogging*
could be instructive.

The OP seems to indicate that each lamp has its own dropping resistor, and
works off 6V, so a parallel connection is appropriate. If they were just
naked LEDs, then of course the series connection is better.

Cheers!
Rich

 

[Jon]

"JeffM" <jeffm_@email.com> wrote in message
news:704d858e-3afb-4390-9d4b-9dd9c5050792@n10g2000prj.googlegroups.com...

Jon wrote:
simply connect them in parallel

Wiring LEDs in parallel is almost never a good idea.
Searching this group's archive for *current hogging*
could be instructive.
As has been mentioned,
a series configuration is generally preferable with LEDs.

As has been mentioned,
figuring out what presently limits the current would be a good plan.

Connect the light units in parallel, not the LEDs. I thought this much
was clear when I described using a common 6 volt source for both units.

An LED rewire is likely in order if you opt to use a blocking oscillator
design.







--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[Jon]

"Rich Grise" <richg@example.net.invalid> wrote in message
news:ib9ga4$36j$1@news.eternal-september.org...

JeffM wrote:

Jon wrote:
simply connect them in parallel

Wiring LEDs in parallel is almost never a good idea.
Searching this group's archive for *current hogging*
could be instructive.

The OP seems to indicate that each lamp has its own dropping resistor, and
works off 6V, so a parallel connection is appropriate. If they were just
naked LEDs, then of course the series connection is better.

Cheers!
Rich

Thanks Rich...you got it exactly.




--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[whit3rd]

On Nov 7, 3:48 pm, Mint <chocolatemint77...@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Four AA cells is about the same as three lead/acid cells: get a
6V gel cell rechargeable battery for this. Most generators have
chassis GROUND and AC output, you'll need capacitor and two
diodes to make a voltage-doubler rectifier for that (the generator
sets don't produce too much current, probably you can
wire directly to the gel cell without any limiter).

 

[Mint]

On Nov 8, 6:48 pm, whit3rd <whit...@gmail.com> wrote:

On Nov 7, 3:48 pm, Mint <chocolatemint77...@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Four AA cells is about the same as three lead/acid cells: get a
6V gel cell rechargeable battery for this.  Most generators have
chassis GROUND and AC output, you'll need capacitor and two
diodes to make a voltage-doubler rectifier for that (the generator
sets don't produce too much current, probably you can
wire directly to the gel cell without any limiter).

You have come the closest to what might be best.

Can the gel batteries be charged many times?

I have some step down transformers I took off various devices.
May have a 6V one that can be modified.

I would like the battery to be more cost effective than NiMh
batteries.

Thanks,
Andy

 

[Mint]

On Nov 8, 12:41 pm, Rich Grise <ri...@example.net.invalid> wrote:

JeffM wrote:
Jon wrote:
simply connect them in parallel

Wiring LEDs in parallel is almost never a good idea.
Searching this group's archive for *current hogging*
could be instructive.

The OP seems to indicate that each lamp has its own dropping resistor, and
works off 6V, so a parallel connection is appropriate. If they were just
naked LEDs, then of course the series connection is better.

Cheers!
Rich

I don't need any modifications to the LEDs.
They are already in a working headlamp and backlight.

Andy

 

[Mint]

On Nov 7, 8:25 pm, "Jon" <Why_bother@this_task.com> wrote:

"Rich Grise" <ri...@example.net.invalid> wrote in message

news:ib7ebo$t2f$1@news.eternal-september.org...



Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Depending on the Vf of the LEDs, you could probably wire them in series
on the appx. 6V, with an appropriate series resistor. Of course, check
each lamp for a resistor in the circuit when you hack them. ;-)

Cheers!
Rich

The lamps are already running on 6 volts...simply connect them in parallel
to a 6
volt source such as a lantern battery...it has plenty of capacity for a long
run time.
This will eliminate the low capacity AA cells.

You might consider a blocking oscillator design which you could house in the
battery box.  There are many examples on the web.

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

Lantern battery's higher capacity would be good .

It would be easy to take off to reduce weight when I don't need it.
My bike weighs 43 lbs. now.

Don't have a car right now, so my bike is my car.

Andy

 

[Don Klipstein]

In <65082846-6139-4725-9b0b-676e361aa13f@p7g2000prb.googlegroups.com>,
Mint wrote:

On Nov 8, 6:48 pm, whit3rd <whit...@gmail.com> wrote:
On Nov 7, 3:48 pm, Mint <chocolatemint77...@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Four AA cells is about the same as three lead/acid cells: get a
6V gel cell rechargeable battery for this.  Most generators have
chassis GROUND and AC output, you'll need capacitor and two
diodes to make a voltage-doubler rectifier for that (the generator
sets don't produce too much current, probably you can
wire directly to the gel cell without any limiter).

You have come the closest to what might be best.

Can the gel batteries be charged many times?

Yes, they can.

I would add one thing: When a power source is constantly connected and
spends a lot of time able to charge the battery, I would add a voltage
regulator circuit to limit charging of the 6V lead-acid battery to 6.9
volts (conservative, in case charging is common and the battery does not
encounter being deeply discharged).

A more aggressive voltage to get the battery more completely charged is
7.1-7.2 volts. However, 6.9 volts is a more conservative voltage that
gets the battery somewhere around 85% charged and avoids electrolysing the
water in the electrolyte. (There is a temperature coefficient to this,
and I don't remember it.) If you want super-conservative, you could go
for 6.8 volts.

You can make your regulator circuit a low-dropout type that has minimal
requirement for the supply voltage to exceed the output voltage, and to
continue to pass current even if the input voltage is below regulation
target as long as output voltage is lower still. This only requires a
good P-channel power MOSFET, an op-amp such as a section of an LM324, a
few resistors, a voltage reference (I like 690-700 nm red LEDs, such as
many Panasonic ones available at Digi-Key), and not too much else besides
some tinkering and creativity and good attitude.

I have some step down transformers I took off various devices.
May have a 6V one that can be modified.

I would like the battery to be more cost effective than NiMh
batteries.

For bike-generator-powered, I like lead-acid and Li-ion. Lead-acid
is easier. Li-ion is lighter weight, but requires special circuitry due
to zero tolerance of overcharging to the extent of outgassing and zero
tolerance of overdischarge, while lead-acid merely suffers a bit of
degradation from minor overcharging and overdischarging followed shortly
by recharging.

Ni-MH is good for bike lights, but good for recharging off-road. They
don't like overcharging a lot, and detection of "full charge" by "smart
chargers" tends to be based on detecting directly (by temperature) or
indirectly (by voltage) a temperature rise that occurs when overcharge
begins. This works better when charging current is sufficient to recharge
these from empty to full in around or less than 4 hours. Packs of NiMH
cells larger than AA will probably work OK with "smart-charging" that
takes 5 or 6 hours.

They also want avoidance of being discharged below 1, maybe as high as
1.1 volts per cell in series strings, and no Ni-MH cells to be
overdischarged past zero cell voltage by other cells in series with them.
--
- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In <52c46f33-4c95-4a39-8592-4753a8137802@y2g2000prf.googlegroups.com>,
Mint wrote:

On Nov 7, 8:25 pm, "Jon" <Why_bother@this_task.com> wrote:
"Rich Grise" <ri...@example.net.invalid> wrote in message

news:ib7ebo$t2f$1@news.eternal-september.org...

Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Depending on the Vf of the LEDs, you could probably wire them in series
on the appx. 6V, with an appropriate series resistor. Of course, check
each lamp for a resistor in the circuit when you hack them. ;-)

Cheers!
Rich

The lamps are already running on 6 volts...simply connect them in parallel
to a 6
volt source such as a lantern battery...it has plenty of capacity for a long
run time.
This will eliminate the low capacity AA cells.

You might consider a blocking oscillator design which you could house in the
battery box.  There are many examples on the web.

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

Lantern battery's higher capacity would be good .

It would be easy to take off to reduce weight when I don't need it.
My bike weighs 43 lbs. now.

Don't have a car right now, so my bike is my car.

My main "commuting car" and my main "delivery truck" for my "day job"
weighs 24 pounds, including basket, excluding lights, excluding the
fenders (likely 1 additional pound) that I ought to add to increase my
comfort of riding in rain.

My youngest brother described it "back to me" as being "almost as simple
as an anvil". I think this vehicle is not much more delicate than one.

I probably have 30,000-35,000 miles on it already in 4 years. I expect
this vehicle to last at least another year or two more.

This tough vehicle is a Bianchi Pista. My main customization of it is
to regear it to a slightly lower gear ratio - still good for top speeds of
35 MPH when I am the one driving it. And, at age 49 I often outrun
cycling team guys on road bikes and bicycle messengers on track bikes
with higher gear ratio going uphill, often also on level road, while my
clothes are less aerodynamic, my bike has a basket, and my bike has only
one gear ratio ("passing gear").
Part of this is attitude and part is experience, with lots of practice -
I use this vehicle for a major part of making my living, as well as a
majority of my commuting to my "day job". Oh, and did I say "attitude"
enough?
--
- Don Klipstein (don@misty.com)

 

[Jasen Betts]

On 2010-11-07, Mint <chocolatemint77581@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
Andy

Most likely you can run a cable from the battery compartment of one to
the battery compartment of the other and just use one set of AA cells.

Doing this in such a way that the lights can stillbe removed could be
tricky.



--
ɹǝpun uʍop ɯoɹɟ sƃuıʇǝǝɹ⅁

 

[Mint]

On Nov 8, 10:20 pm, d...@manx.misty.com (Don Klipstein) wrote:

In <52c46f33-4c95-4a39-8592-4753a8137...@y2g2000prf.googlegroups.com>,



Mint wrote:
On Nov 7, 8:25 pm, "Jon" <Why_bother@this_task.com> wrote:
"Rich Grise" <ri...@example.net.invalid> wrote in message

news:ib7ebo$t2f$1@news.eternal-september.org...

Mint wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Depending on the Vf of the LEDs, you could probably wire them in series
on the appx. 6V, with an appropriate series resistor. Of course, check
each lamp for a resistor in the circuit when you hack them. ;-)

Cheers!
Rich

The lamps are already running on 6 volts...simply connect them in parallel
to a 6
volt source such as a lantern battery...it has plenty of capacity for a long
run time.
This will eliminate the low capacity AA cells.

You might consider a blocking oscillator design which you could house in the
battery box.  There are many examples on the web.

--- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

Lantern battery's higher capacity would be good .

It would be easy to take off to reduce weight when I don't need it.
My bike weighs 43 lbs. now.

Don't have a car right now, so my bike is my car.

  My main "commuting car" and my main "delivery truck" for my "day job"
weighs 24 pounds, including basket, excluding lights, excluding the
fenders (likely 1 additional pound) that I ought to add to increase my
comfort of riding in rain.

  My youngest brother described it "back to me" as being "almost as simple
as an anvil".  I think this vehicle is not much more delicate than one.

  I probably have 30,000-35,000 miles on it already in 4 years.  I expect
this vehicle to last at least another year or two more.

  This tough vehicle is a Bianchi Pista.  My main customization of it is
to regear it to a slightly lower gear ratio - still good for top speeds of
35 MPH when I am the one driving it.  And, at age 49 I often outrun
cycling team guys on road bikes and bicycle messengers on track bikes
with higher gear ratio going uphill, often also on level road, while my
clothes are less aerodynamic, my bike has a basket, and my bike has only
one gear ratio ("passing gear").
 Part of this is attitude and part is experience, with lots of practice -
I use this vehicle for a major part of making my living, as well as a
majority of my commuting to my "day job".  Oh, and did I say "attitude"
enough?
--
 - Don Klipstein (d...@misty.com)

Interesting information.

Do you have a horn on your rig?

Have you considered carrying a short range cell phone jammer?

Andy

 

[Mint]

On Nov 9, 4:22 am, Jasen Betts <ja...@xnet.co.nz> wrote:

On 2010-11-07, Mint <chocolatemint77...@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
              Andy

Most likely you can run a cable from the battery compartment of one to
the battery compartment of the other and just use one set of AA cells.

Doing this in such a way that the lights can stillbe removed could be
tricky.

--
ɹǝpun uʍop ɯoɹɟ sƃuıʇǝǝɹ⅁

 

On Sun, 7 Nov 2010 15:48:22 -0800 (PST), Mint
<chocolatemint77581@yahoo.com> wrote:

I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
Andy

Mount neodymium magnets to the wheels and put coils on the frame -
then spend months designing an efficient battery charging and
monitoring scheme. Or just buy a hub mounted generator for ~$300.

Rechargeable batteries and charger, are probably the practical
solution.

 

[Mint]

On Nov 9, 9:43 am, default wrote:

On Sun, 7 Nov 2010 15:48:22 -0800 (PST), Mint

chocolatemint77...@yahoo.com> wrote:
I have two bike lights that run off with 4 AA batteries each.

I would like to make a single power source to run to them instead of
frequently changing out
batteries.

Both lights use LEDs.

I would appreciate any ideas.

Thanks,
             Andy

Mount neodymium magnets to the wheels and put coils on the frame -
then spend months designing an efficient battery charging and
monitoring scheme.  Or just buy a hub mounted generator for ~$300.

Rechargeable batteries and charger, are probably the practical
solution.  

You gave me an idea.

Solar cells to be used for my lead acid battery.

Andy