Using cordless tool batteries to power a drone

John Doe wrote
><698839253X6D445TD@nospam.org> wrote: 
>> Did you try flying with 2 lipos in parallel? 
>
>You mean ions. No. I'm not that bullheaded. 

No I meant lipos, could give you 25 minutes flying time.

About metering:
BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC Voltage Frequency Tester
was about 31 $ IIRC ebay auction, now these cost 65 $ it seems.
So far it works OK.
Not all clamp on meters are DC capable, the AC ones are just transformers,
so beware.
But a normal 10 A meter should perhaps work too, you will lose some voltage,

<698839253X6D445TD@nospam.org> wrote:

> [double the lipos] could give you 25 minutes flying time.

But, as I'm sure you know... Doubling the battery weight reduces flight 
time, how much depends on the drone.

> BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC
> Voltage Frequency Tester 

How useful is it for this hobby? Given the voltage reading on your FPV.

I just bought a heat gun, my first. Should've bought one decades ago. 
Probably useful for shaping hot melt glue, in addition to heat shrink 
tubing.

After testing again...

The 3000 mA hour 20700x3 homemade battery pack weighs 225 g.
It flew for 9 minutes before the alarm, then stopped flying at 11 
minutes.

The 2800 mA hour lithium polymer battery pack weighs 209 g.
It flew for 15 minutes before the alarm, then stopped flying 25 seconds 
later.

Lithium ions go out with a sputter.

John Doe wrote
><698839253X6D445TD@nospam.org> wrote:
>
>> [double the lipos] could give you 25 minutes flying time.
>
>But, as I'm sure you know... Doubling the battery weight reduces flight 
>time, how much depends on the drone.

Yes, but it does not double the total weight (drone + batteries).
so there always is some gain,. provided you get lift-off.


>> BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC
>> Voltage Frequency Tester 
>
>How useful is it for this hobby? Given the voltage reading on your FPV.

I wanted to know how much current the Hubsan draws at full throttle,
so what [ebay] converter to buy to convert 3 liion to 7.2 V.
And because I have been testing some batteries with these resistors:
 http://panteltje.com/pub/power_resistors_IMG_6291.JPG
And also for the indefinite flight time project:
 http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
 http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
drone powered via thin coax, will stay in the air forever.
The idea being to use it to put an antenna very high up there...

The DC capable clamp-on meters are great,
measuring current while charging batteries, in your car, in your boat,
any place were you need to measure high DC current and do not want - 
or cannot cut the cables to put an amp meter in series.
Thing works from 50 to 100 mA upwards
I also have a cheap AC only one, never use that,



>I just bought a heat gun, my first. Should've bought one decades ago. 
>Probably useful for shaping hot melt glue, in addition to heat shrink 
>tubing.

I use a lighter for heat shrink tubing....
Or the soldering iron (clean afterwards).


>After testing again...
>
>The 3000 mA hour 20700x3 homemade battery pack weighs 225 g.
>It flew for 9 minutes before the alarm, then stopped flying at 11 
>minutes.
>
>The 2800 mA hour lithium polymer battery pack weighs 209 g.
>It flew for 15 minutes before the alarm, then stopped flying 25 seconds 
>later.
>
>Lithium ions go out with a sputter.

Yes I am sure they are good for many things, but not so much for drones.

On Sat, 15 Dec 2018 15:04:25 GMT, <698839253X6D445TD@nospam.org>
wrote:

>About metering:
>BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC Voltage Frequency Tester
>was about 31 $ IIRC ebay auction, now these cost 65 $ it seems.
>So far it works OK.

I've been shopping for a clamp type DC ammeter to replace various
lesser quality devices which I use for measuring DC stick arc welder
current, spot welder DC peak current, automobile charging current, DC
starter current, LED flashlight current, radio transmitter DC current,
solar panel short circuit current, etc.  I didn't know that the
MS2018a would measure DC current through the clamp.  Looks like it
should work.  However, I'm tempted to buy a Mastech MS2109a, which is
similar but has a better front panel layout and adds a thermocouple
thermometer and NCV (Non-Contact Voltage) AC tester for approximately
the same price.
<https://www.ebay.com/sch/i.html?_nkw=MASTECH+MS2109a>

>Not all clamp on meters are DC capable, the AC ones are just transformers,
>so beware.

I haven't found a way to filter Google or eBay searches for clamp
meters that will work with DC through the clamp.  Most meters will do
both AC and DC current through the test leads, some will do AC through
the clamp, but very few will do AC and DC through the clamp.  One
trick I've found is to look at the silk screening on the ammeter
ranges.  If it shows a stylized sine wave over a solid line, it should
work with both AC and DC.  The clamp also has + and - markings.

>But a normal 10 A meter should perhaps work too, you will lose some voltage,

Very little voltage drop.  A 10A 100mv shunt has a resistance of 0.01
ohms and will drop, umm... 100mv at 10amps:
<https://www.murata-ps.com/data/meters/dpm_shunts.pdf>

I have some opinions on what's wrong with the quadcopter.  However,
I'll wait until I see some voltage and current measurements and graphs
performed in a test stand (like your chair test).  My guess(tm) is
that this sounds like a high resistance connection between the battery
and the ESC (electronic speed control).  Something seems to be
prematurely announcing that the battery is depleted.  An unwanted
voltage drop in the wiring would do that.

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

Jeff Liebermann <jeffl@cruzio.com> wrote:

> I have some opinions on what's wrong with the quadcopter.  However,
> I'll wait until I see some voltage and current measurements and graphs
> performed in a test stand (like your chair test).  My guess(tm) is
> that this sounds like a high resistance connection between the battery
> and the ESC (electronic speed control).  Something seems to be
> prematurely announcing that the battery is depleted.  An unwanted
> voltage drop in the wiring would do that.

I suspect there's something weird going on in this particular drone, but 
the low-voltage warning can be set low enough to get full use out of 
lithium polymer batteries.

I might try lithium ions for some other drone, but that's it for this 
one. The lithium-ion pack I made for the controller is working superbly. 

"Jeff Liebermann"  wrote in message 
news:uu0b1ela5h7jte6hctg1hlkejkai5e9ob7@4ax.com...
>
>On Sat, 15 Dec 2018 15:04:25 GMT, <698839253X6D445TD@nospam.org>
>wrote:
>
>>About metering:
>>BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC Voltage 
>>Frequency Tester
>>was about 31 $ IIRC ebay auction, now these cost 65 $ it seems.
>>So far it works OK.
>
>I've been shopping for a clamp type DC ammeter to replace various
>lesser quality devices which I use for measuring DC stick arc welder
>current, spot welder DC peak current, automobile charging current, DC
>starter current, LED flashlight current, radio transmitter DC current,
>solar panel short circuit current, etc.  I didn't know that the
>MS2018a would measure DC current through the clamp.  Looks like it
>should work.  However, I'm tempted to buy a Mastech MS2109a, which is
>similar but has a better front panel layout and adds a thermocouple
>thermometer and NCV (Non-Contact Voltage) AC tester for approximately
>the same price.
><https://www.ebay.com/sch/i.html?_nkw=MASTECH+MS2109a>
>
>>Not all clamp on meters are DC capable, the AC ones are just transformers,
>>so beware.
>
>I haven't found a way to filter Google or eBay searches for clamp
>meters that will work with DC through the clamp.  Most meters will do
>both AC and DC current through the test leads, some will do AC through
>the clamp, but very few will do AC and DC through the clamp.  One
>trick I've found is to look at the silk screening on the ammeter
>ranges.  If it shows a stylized sine wave over a solid line, it should
>work with both AC and DC.  The clamp also has + and - markings.
>
>>But a normal 10 A meter should perhaps work too, you will lose some 
>>voltage,
>
>Very little voltage drop.  A 10A 100mv shunt has a resistance of 0.01
>ohms and will drop, umm... 100mv at 10amps:
><https://www.murata-ps.com/data/meters/dpm_shunts.pdf>
>
>I have some opinions on what's wrong with the quadcopter.  However,
>I'll wait until I see some voltage and current measurements and graphs
>performed in a test stand (like your chair test).  My guess(tm) is
>that this sounds like a high resistance connection between the battery
>and the ESC (electronic speed control).  Something seems to be
>prematurely announcing that the battery is depleted.  An unwanted
>voltage drop in the wiring would do that.

I've got two Uni-T meters (http://www.uni-trend.com/), both 4000 count 
models, one a true RMS autoranging DVM and the other a clamp ammeter DVM, 
model UT204 which does AC and DC and autoranges between 40A and 400A scales. 
I've used it to check starter draw on a car and the output of a 10W solar 
panel (0.22 A that day) and I'm happy with it.  They have lots of models 
with different features, and lots of sellers on amazon and ebay.  The Uni-T 
meters seems to have good accuracy and useful features, but get their low 
cost from slow settling times.  Over a second per screen update and often 
three updates to get a stable reading so 3-5 seconds total.  For my needs 
that works.

If you don't use a clamp-on meter be sure to check the manual for your 
meter.  Lots of the cheaper meters with a 10A scale bury a truly wimpy duty 
cycle in the fine print.  I've seen 15 seconds of 10A measurement followed 
by ten-plus minutes of required cooldown in at least one of the Uni-T meters 
and some other brand I can't remember right now.

-- 
Regards,
Carl Ijames 

On Sat, 15 Dec 2018 21:14:59 -0500, "Carl"
<carl.ijamesXYZ@ZYXverizon.net> wrote:

>><https://www.ebay.com/sch/i.html?_nkw=MASTECH+MS2109a>

MS2109a data sheet:
<http://www.mastech-group.com/products.php?cate=95&PNo=209>

More Mastech clamp meters:
<http://www.mastech-group.com/products.php?cate=95> 
<http://www.mastech-group.com/products.php?cate=95&page=2>

>I've got two Uni-T meters (http://www.uni-trend.com/), both 4000 count 
>models, one a true RMS autoranging DVM and the other a clamp ammeter DVM, 
>model UT204 which does AC and DC and autoranges between 40A and 400A scales. 

True RMS would be nice to have, but is not necessary for what I expect
to be mostly DC current measurements.

Sigh.  I went to the Uni-T web pile and tried to look for meters.
Every link link I click returns a "404" (nobody home).  Despite my
having an uncontrollable urge to buy something immediately, I'll wait
a day or two for someone to fix the Uni-T web pile or server.

>I've used it to check starter draw on a car and the output of a 10W solar 
>panel (0.22 A that day) and I'm happy with it.  They have lots of models 
>with different features, and lots of sellers on amazon and ebay.  The Uni-T 
>meters seems to have good accuracy and useful features,

Thanks.  I'll do some reading and see what they have to offer.

>but get their low 
>cost from slow settling times.  Over a second per screen update and often 
>three updates to get a stable reading so 3-5 seconds total.  For my needs 
>that works.
>
>If you don't use a clamp-on meter be sure to check the manual for your 
>meter.  Lots of the cheaper meters with a 10A scale bury a truly wimpy duty 
>cycle in the fine print.  I've seen 15 seconds of 10A measurement followed 
>by ten-plus minutes of required cooldown in at least one of the Uni-T meters 
>and some other brand I can't remember right now.

Argh.  I didn't realize that this was a problem with DC clamp meters.
I just skimmed the Mastech MS2109a manual
<https://panda-bg.com/datasheet/2145-340549-MS2109A-clamp-meter-mastech.pdf>
but didn't find any mention of a cool down period.  
For sampling rate, it claims:
"Sampling rate: about 3 times/s, simulation bar 30 times/s."
Incidentally, the highest count is 5999 which is needed for the 600A
scale.


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

On Sun, 16 Dec 2018 02:14:18 -0000 (UTC), John Doe
<always.look@message.header> wrote:

>Jeff Liebermann <jeffl@cruzio.com> wrote:
>
>> I have some opinions on what's wrong with the quadcopter.  However,
>> I'll wait until I see some voltage and current measurements and graphs
>> performed in a test stand (like your chair test).  My guess(tm) is
>> that this sounds like a high resistance connection between the battery
>> and the ESC (electronic speed control).  Something seems to be
>> prematurely announcing that the battery is depleted.  An unwanted
>> voltage drop in the wiring would do that.
>
>I suspect there's something weird going on in this particular drone, but 
>the low-voltage warning can be set low enough to get full use out of 
>lithium polymer batteries.

I can see that I'm not getting through to you.  Please excuse my
abrasive, rude, undiplomatic, and short tempered manners.  

Here's what you should be doing:

1.  Setup your drone in a manner similar to Jan Panteltje's test
chair:
<http://panteltje.com/pub/hubsan_h501s_current_test_full_throttle_IMG_6290.JPG>

2.  Take DVM and place it across the battery terminals as close to the
actual battery as possible.  You want to measure the actual battery
voltage.

3.  Take a 2nd DVM and place it as close to the place where the ESC
distributes the power to the various motors.  That would be the DC
input to the ESC.  If the low voltage measurement device is located
elsewhere, use that connection.

4.  If you have an adapter for your XT60 battery connector for current
measurement, attach it and also record the current draw ever 30
seconds.

5.  Run the drone in the chair at something resembling normal flight
RPM (not full power).  With a paper pad and pen, record the voltages
every 30 seconds.  When the low voltage alarm is triggered, record the
time.  Let it run until the controller or ESC declares the battery to
be discharged.  Draw a graph.  If my guess is correct, the graph will
look very strange and that there will be a substantial voltage
difference between the battery terminal voltage and the ESC voltage.

>I might try lithium ions for some other drone, but that's it for this 
>one. The lithium-ion pack I made for the controller is working superbly. 

Really.  Have you calculated what your runtime should be based on the
average current drain and battery ma-hr rating?  Be sure to check the
data sheet for the LiIon cells for the ma-hr capacity at whatever
current your motors are drawing.  How close is your flight time to the
theoretical runtime?

-- 
Jeff Liebermann     jeffl@cruzio.com
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 Sat, 15 Dec 2018 15:04:25 GMT, <698839253X6D445TD@nospam.org>
>wrote:
>
>>About metering:
>>BTW I use a MASTECH MS2108 Digital True RMS Clamp Multimeter AC DC Voltage Frequency Tester
>>was about 31 $ IIRC ebay auction, now these cost 65 $ it seems.
>>So far it works OK.
>
>I've been shopping for a clamp type DC ammeter to replace various
>lesser quality devices which I use for measuring DC stick arc welder
>current, spot welder DC peak current, automobile charging current, DC
>starter current, LED flashlight current, radio transmitter DC current,
>solar panel short circuit current, etc.  I didn't know that the
>MS2018a would measure DC current through the clamp.  Looks like it
>should work.  However, I'm tempted to buy a Mastech MS2109a, which is
>similar but has a better front panel layout and adds a thermocouple
>thermometer and NCV (Non-Contact Voltage) AC tester for approximately
>the same price.
><https://www.ebay.com/sch/i.html?_nkw=MASTECH+MS2109a>

Yes, those things are getting better all the time,
I notice that if I google
 'MS2109a user manual'
then I get all the info on that thing as pdf.



>>But a normal 10 A meter should perhaps work too, you will lose some voltage,
>
>Very little voltage drop.  A 10A 100mv shunt has a resistance of 0.01
>ohms and will drop, umm... 100mv at 10amps:
><https://www.murata-ps.com/data/meters/dpm_shunts.pdf>

Indeed, external shunt,
but if he uses a multimeter meter those test leads are very thin and crap,
for current, you will need short thick test leads to the meter,


>I have some opinions on what's wrong with the quadcopter.  However,
>I'll wait until I see some voltage and current measurements and graphs
>performed in a test stand (like your chair test).  My guess(tm) is
>that this sounds like a high resistance connection between the battery
>and the ESC (electronic speed control).  Something seems to be
>prematurely announcing that the battery is depleted.  An unwanted
>voltage drop in the wiring would do that.

For the original lipos the wiring is very short, big connectors, 
don't know his setup.

Jeff Liebermann wrote

>I just skimmed the Mastech MS2109a manual
><https://panda-bg.com/datasheet/2145-340549-MS2109A-clamp-meter-mastech.pdf>
>but didn't find any mention of a cool down period.  
>For sampling rate, it claims:
>"Sampling rate: about 3 times/s, simulation bar 30 times/s."

I can confirm that for the Mastech MS2108,
I can set the current limit for my battery charger with it and it reacts as fast as I can turn that 10 turns trimpot.

Do not know about a cool down period, never measure high DC currents for a very long time.
Before measuring I press the zero button once.
And I did put 3 eneloop 1.5 V AAA batteries in it so it is always ready.