18650 Batteries and Why Dynamos Can't Competer

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like 18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Your calculations are incorrect.

As a scientist....

Calculations do not = real life.

Andy

On Fri, 6 Mar 2015 19:11:16 -0800 (PST), Andy K
wrote:

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like 18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Your calculations are incorrect.

As a scientist....

Calculations do not = real life.

Andy
Perhaps your 13 watt light is like the 12 watt LED MR16 lights I
bought. 4 3 watt cree chips - and they only draw 500 ma on 12 volts.

Sure there is 12 watts of LED chips there, but they are only running
at half power.

On Friday, March 6, 2015 at 10:27:35 PM UTC-5, wrote:
On Fri, 6 Mar 2015 19:11:16 -0800 (PST), Andy K
wrote:

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like 18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Your calculations are incorrect.

As a scientist....

Calculations do not = real life.

Andy
Perhaps your 13 watt light is like the 12 watt LED MR16 lights I
bought. 4 3 watt cree chips - and they only draw 500 ma on 12 volts.

Sure there is 12 watts of LED chips there, but they are only running
at half power.

on the 6V ...there's YUSA AND BB VRLA for a mmmmmm TACTICAL Streamlight beam light mounted on the van's partition wall.

No science. The batts put out a lot of light for a long time.

Then as posted bought a XMASS 2 pack of 3 color headlamps from Homedepot.

Recently used for an all night blinking red under the windshield.

Surprise was after the unit sits idle all day, the batt gets up enough juice to repower the white LED for an hour or two while I search for fresh batteries.

On Fri, 6 Mar 2015 19:11:16 -0800 (PST), Andy K
wrote:

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like 18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.

Your calculations are incorrect.

Where is my error?

Perhaps it might be helpful if you answered my question. How big is
this SLA battery that lasts for an unspecified number of hours with a
13 watt load and only needs recharging every 3 months? If it's real,
I want one for my bicycle(s).

As a scientist....

As a scientist, you should be able to do the calculations yourself.
How long will your badly specified battery run your two 500 lumen
headlamps plus your 300 lumen tail lamp.

I did make 2 assumptions. I assumed that you're using decent LED's,
which for todays technology, generates about 100 lumens/watt consumed.
Cree has claimed something like 200 or 300 lumens per watt, but they
required cooling the LED. I also assumed you're not interested in
prematurely killing your SLA battery and are therefore only drawing
50% of it's rated capacity. You could draw more, but the battery life
will suffer badly.

Calculations do not = real life.

Sorry, but I only understand numbers. Numbers, measurements, and
calculations are real life. Everything else is conjecture,
speculation, and theory.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 06 Mar 2015 22:27:34 -0500, wrote:

Perhaps your 13 watt light is like the 12 watt LED MR16 lights I
bought. 4 3 watt cree chips - and they only draw 500 ma on 12 volts.

Sure there is 12 watts of LED chips there, but they are only running
at half power.

Ummm... a few problem. He has two lights. A pair of 500 lumen light
up front, and a single 300 lumen light in back. I decided that all
the LED's are 100 lumens per watt, yielding 10 watts up front, and 3
watts in back for a total draw of 13 watts.

If you're suggesting that this might e similar to an MR16 light of
equivalent luminous efficacy, I'm stuck with finding a maker and model
number for an 10 watt MR16 light for the front, and a 3 watt MR16
light for the rear. I can probably come close:

First try is:
Philips 420190
http://download.p4c.philips.com/l4b/9/929000219604_na/929000219604_na_pss_aenaa.pdf
10 watts and 490 lumens or 50 lumens per watt. Not exactly my
optimistic 100 lumens per watt. So, to get 100 lumens out this light,
I would need to go to a 20 watt light. Hardly half-power, more like
double power.

1OPM and I have to be up early to help install antennas. To be
continued on Monday, if I survive.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 07 Mar 2015 21:40:20 -0800, Jeff Liebermann
wrote:

On Fri, 6 Mar 2015 19:11:16 -0800 (PST), Andy K
wrote:

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like 18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.

Your calculations are incorrect.

Where is my error?

Perhaps it might be helpful if you answered my question. How big is
this SLA battery that lasts for an unspecified number of hours with a
13 watt load and only needs recharging every 3 months? If it's real,
I want one for my bicycle(s).

As a scientist....

As a scientist, you should be able to do the calculations yourself.
How long will your badly specified battery run your two 500 lumen
headlamps plus your 300 lumen tail lamp.

I did make 2 assumptions. I assumed that you're using decent LED's,
which for todays technology, generates about 100 lumens/watt consumed.
Cree has claimed something like 200 or 300 lumens per watt, but they
required cooling the LED. I also assumed you're not interested in
prematurely killing your SLA battery and are therefore only drawing
50% of it's rated capacity. You could draw more, but the battery life
will suffer badly.

Calculations do not = real life.

Sorry, but I only understand numbers. Numbers, measurements, and
calculations are real life. Everything else is conjecture,
speculation, and theory.


Lets see now. Say an hour to work and an hour back on a daily basis =
2 x 13 x 30.42 days x 3 = 2373 WH, to be safe double that so a 4745
WH, say 5,000WH battery.

I can source you a lovely Lithium Ion battery that size ... 622mm X
197 mm X 355 mm at 58Kg. In English that is 2'1/2" x 7-3/4" x 14" and
128 lb.

I'm sure it will make a welcome addition to your commuting bike :-)
--
Cheers,

John B.

John B. Slocomb wrote:
On Sat, 07 Mar 2015 21:40:20 -0800, Jeff Liebermann
wrote:

On Fri, 6 Mar 2015 19:11:16 -0800 (PST), Andy K
wrote:

On Thursday, March 5, 2015 at 12:23:07 PM UTC-6, Jeff Liebermann wrote:
On Thu, 5 Mar 2015 09:31:28 -0800 (PST), Andy K
wrote:

The point is that I am not changing batteries out every 2 days like
18650 and aaa battery users are.

You didn't answer my question. What's the rating on your 6v SLA
battery (amp-hrs)? How many hours does it it run in your 3 month
cycle? Efficient DC-to-DC switching regulator or inefficient LDO
linear regulator to get from 6V to 4.5V (or just 2 diodes in series)?

I don't believe that you can do a 3 month charge cycle with a 13 watt
lighting system and a realistic number of hours of operation per day.
That's why I did the calculations errr... guesstimations.

Your calculations are incorrect.

Where is my error?

Perhaps it might be helpful if you answered my question. How big is
this SLA battery that lasts for an unspecified number of hours with a
13 watt load and only needs recharging every 3 months? If it's real,
I want one for my bicycle(s).

As a scientist....

As a scientist, you should be able to do the calculations yourself.
How long will your badly specified battery run your two 500 lumen
headlamps plus your 300 lumen tail lamp.

I did make 2 assumptions. I assumed that you're using decent LED's,
which for todays technology, generates about 100 lumens/watt consumed.
Cree has claimed something like 200 or 300 lumens per watt, but they
required cooling the LED. I also assumed you're not interested in
prematurely killing your SLA battery and are therefore only drawing
50% of it's rated capacity. You could draw more, but the battery life
will suffer badly.

Calculations do not = real life.

Sorry, but I only understand numbers. Numbers, measurements, and
calculations are real life. Everything else is conjecture,
speculation, and theory.


Lets see now. Say an hour to work and an hour back on a daily basis =
2 x 13 x 30.42 days x 3 = 2373 WH, to be safe double that so a 4745
WH, say 5,000WH battery.

I can source you a lovely Lithium Ion battery that size ... 622mm X
197 mm X 355 mm at 58Kg. In English that is 2'1/2" x 7-3/4" x 14" and
128 lb.

I'm sure it will make a welcome addition to your commuting bike :-)

It's just this sort of "weight weenie" attitude that's ruining cycling for
normal people :-)

8 amp hr battery

I erred on the two headlights, have 2 1000 lumen Crees.

Use them 10 - 15 mins/day.

Andy

On Mon, 9 Mar 2015 19:41:43 -0700 (PDT), Andy K
wrote:

8 amp hr battery
I erred on the two headlights, have 2 1000 lumen Crees.
Use them 10 - 15 mins/day.
Andy

Ok, I'll use those numbers. Let's see if it works.

I'll assume a 6V 8A-hr (48 watt-hrs) SLA battery and an average of 12
mins runtime per day.

At 100 lumens per watt (very optimistic), your 2000 lumens LED's will
requi
2000 lumens / 100 lumens/watt = 20 watts
of power at full brightness. Never mind the tail light and 6v-4.5v
converter efficiency for now, which will only make the numbers worse.
Your 48 watt-hr SLC can safely be discharged to 50%, but I'll assume
that you don't recharge until the battery is obvious discharged, which
would be about 75% depleted.
Available energy = 48 watt-hrs * 0.75 = 36 watt-hrs
At full brightness, your lights burn 20 watts giving you:
36 watt-hrs / 20 watts = 1.8 hrs = 108 minutes
of continuous operation. At 12 minutes operation per day, you can run
for:
108 / 12 = 9 days
before your battery is discharged. That's hardly 3 months. Want to
try again with some better numbers?

My guess(tm) is that the 1000 lumen LED's is advertising hype and that
the LED's were not made by Cree. Much of the lighting junk on eBay
and DX.com has horribly inflated illumination values. If you can't
identify the LED's, perhaps you can measure the current drain of these
lights with a fully charged battery. That should allow me to guess
what LED's are actually being used and approximately how many lumens
they are delivering and for how long your battery will last.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
On Mon, 9 Mar 2015 19:41:43 -0700 (PDT), Andy K
wrote:

8 amp hr battery
I erred on the two headlights, have 2 1000 lumen Crees.
Use them 10 - 15 mins/day.
Andy

Ok, I'll use those numbers. Let's see if it works.

I'll assume a 6V 8A-hr (48 watt-hrs) SLA battery and an average of 12
mins runtime per day.

At 100 lumens per watt (very optimistic), your 2000 lumens LED's will
requi
2000 lumens / 100 lumens/watt = 20 watts
of power at full brightness. Never mind the tail light and 6v-4.5v
converter efficiency for now, which will only make the numbers worse.
Your 48 watt-hr SLC can safely be discharged to 50%, but I'll assume
that you don't recharge until the battery is obvious discharged, which
would be about 75% depleted.
Available energy = 48 watt-hrs * 0.75 = 36 watt-hrs
At full brightness, your lights burn 20 watts giving you:
36 watt-hrs / 20 watts = 1.8 hrs = 108 minutes
of continuous operation. At 12 minutes operation per day, you can run
for:
108 / 12 = 9 days
before your battery is discharged. That's hardly 3 months. Want to
try again with some better numbers?

My guess(tm) is that the 1000 lumen LED's is advertising hype and that
the LED's were not made by Cree. Much of the lighting junk on eBay
and DX.com has horribly inflated illumination values. If you can't
identify the LED's, perhaps you can measure the current drain of these
lights with a fully charged battery. That should allow me to guess
what LED's are actually being used and approximately how many lumens
they are delivering and for how long your battery will last.


You could have LEDs rated at 1000 lumens, but simply not heat sink or drive
them anywhere near that figure :-)