Using cordless tool batteries to power a drone

<698839253X6D445TD@nospam.org> wrote in news:ps3nc8$1d1q$1
@gioia.aioe.org:

> John Doe wrote
>>A 3s 2200 mA hour lipo weighs 183 g???
> 
> Yes, just measured a 40C one at 190 g inclusive huge terminal blocks,
> see picture below.
> 
> Those lipos are cool, 40C, you can start a car with one.
> I used one to replace the sealed lead acid in my tire pump compressor.
> Smaller, lighter, no leaking,
> I have several lipo chargers, those charge at low current,
> Small ones I charge on the lab supply.
> 
> And all that lipo stuff is ebay,
> just read the reviews and recommendation in the RC groups
> to find the right model / seller.
> 
> These are from ebay and work for me:
>  http://panteltje.com/pub/3cell_40C_ebay_lipo_IMG_6682.JPG
> 

The new stuff is called LiFePo.

It flew! It flew! 
My battery pack stayed cool as a cucumber. At first, increasing
throttle would not get the drone off of the ground, until after the
throttle was turned to 0 and then reapplied. 

The batteries probably don't source enough current. I will try the
Dewalt 6 amp hour battery batteries even though I guess those cells
are only two amp hours. 









-- 

I wrote: 

> Disclaimer: I'm not looking for the best drone power supply. I
> enjoy using high quality branded products. Of course it's all made
> in China. That is IMO a good reason to pay close attention to
> branding. I intend to pay VERY close attention to my battery pack
> temperature, and to take the endeavor very slowly. 
> 
> I have a spare Dewalt 20 V Max 6 amp hour battery, and a load of
> new 18650 batteries from an electric monowheel/unicycle I bought
> mainly for the experience. 
> 
> I would bet the 18650s in Dewalt's 9 amp hour FLEX VOLT would
> work, for $200. I suppose trying to find those batteries would be
> impossible due to lack of labeling. 
> 
> I suppose one way to guess at discharge rates is to look at the 
> application the battery is meant for, the run time of the device.
> But of course data is preferable. 
> 
> Any resource for discharge rates of 18650 batteries? 

On Saturday, November 10, 2018 at 1:22:49 AM UTC-5, John Doe wrote:
> It flew! It flew! 
> My battery pack stayed cool as a cucumber. At first, increasing
> throttle would not get the drone off of the ground, until after the
> throttle was turned to 0 and then reapplied. 
> 
> The batteries probably don't source enough current. I will try the
> Dewalt 6 amp hour battery batteries even though I guess those cells
> are only two amp hours. 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> I wrote: 
> 
> > Disclaimer: I'm not looking for the best drone power supply. I
> > enjoy using high quality branded products. Of course it's all made
> > in China. That is IMO a good reason to pay close attention to
> > branding. I intend to pay VERY close attention to my battery pack
> > temperature, and to take the endeavor very slowly. 
> > 
> > I have a spare Dewalt 20 V Max 6 amp hour battery, and a load of
> > new 18650 batteries from an electric monowheel/unicycle I bought
> > mainly for the experience. 
> > 
> > I would bet the 18650s in Dewalt's 9 amp hour FLEX VOLT would
> > work, for $200. I suppose trying to find those batteries would be
> > impossible due to lack of labeling. 
> > 
> > I suppose one way to guess at discharge rates is to look at the 
> > application the battery is meant for, the run time of the device.
> > But of course data is preferable. 
> > 
> > Any resource for discharge rates of 18650 batteries?

Hmmmm... amphour rating says how large the fuel tank is.  What you want to know is how large the fuel line diameter is or maybe the better analogy is how large the fuel pump is.  

If the batteries are the same physical size and the same type, then there shouldn't be a lot of difference unless one is very poorly constructed.  If you want high current and low internal resistance, then the chemistry matters a lot.  I don't know how the different versions of LiIon types vary in this regard but I believe none are poor.  I do know NiMH are rather poor.  NiCad isn't bad at all.  Years ago I had a remote controlled boat.  With Alkaline cells it ran ok.  With NiCads it ran like a bullet.  We didn't have LiIon back then.  

Do you know what chemistry your batteries are?  It should tell you on the cells or in the tool manual. 

Rick C.

gnuarm.deletethisbit@gmail.com wrote: 

> John Doe wrote: 

>> It flew! It flew! My battery pack stayed cool as a cucumber. At
>> first, increasing throttle would not get the drone off of the
>> ground, until after the throttle was turned to 0 and then
>> reapplied. 
>> 
>> The batteries probably don't source enough current. I will try
>> the Dewalt 6 amp hour battery batteries even though I guess those
>> cells are only two amp hours. 

> Hmmmm... amphour rating says how large the fuel tank is.  What you
> want to know is how large the fuel line diameter is or maybe the
> better analogy is how large the fuel pump is.  
> 
> If the batteries are the same physical size and the same type,
> then there shouldn't be a lot of difference unless one is very
> poorly constructed.  If you want high current and low internal
> resistance, then the chemistry matters a lot.  I don't know how
> the different versions of LiIon types vary in this regard but I
> believe none are poor.  I do know NiMH are rather poor.  NiCad
> isn't bad at all.  Years ago I had a remote controlled boat.  With
> Alkaline cells it ran ok.  With NiCads it ran like a bullet.  We
> didn't have LiIon back then.  
> 
> Do you know what chemistry your batteries are?  It should tell you
> on the cells or in the tool manual. 

The chemistry is lithium ion. When first removed from the electric 
unicycle, the faintly printed numbers were researched but no 
information was found. Lithium polymer is commonly used for this 
(drone) application. But I will go with what I have, for now. Next up 
is batteries from my Dewalt cordless tool battery.

I don't mind a current limit, if it's enough to fly (without stunting) 
and if the batteries do not overheat while being pushed to that limit. 
Actually, such a performance limit would be preferable to me at this 
time.

The battery holder is hot melt glued upside down to the underside of 
the drone. So it will automatically and instantly power-off in hard 
landings and in most crashes. It might take some fiddling, but 
hopefully that feature can be well implemented. That might also 
provide some strain relief when the batteries pop out. One foreseeable 
problem is the battery contacts maybe being damaged (compressed) in a 
crash.

I am using ping-pong (table tennis) balls for skids. Much lighter at 
2.6 g each and should do well for skids since they are spherical, 
given the fact drones move in every direction. Should work for bumpers 
too, will see. Easy to apply with hot melt glue, and easy to remove 
with rubbing alcohol. Ping-pong balls make a drone float on water too, 
for what it's worth.

John Doe wroye
>>> It flew! It flew! My battery pack stayed cool as a cucumber. At
>>> first, increasing throttle would not get the drone off of the
>>> ground, until after the throttle was turned to 0 and then
>>> reapplied. 

How is your flight time compared to the lipos?
What drone do you use?

...


>I am using ping-pong (table tennis) balls for skids. Much lighter at 
>2.6 g each and should do well for skids since they are spherical,

Right, I had some larger balls planned for landing on water.
If too big those steal air flow from the propelloers (in my case).

<698839253X6D445TD@nospam.org> wrote:

> John Doe wroye

>>>> It flew! It flew! My battery pack stayed cool as a cucumber. At
>>>> first, increasing throttle would not get the drone off of the
>>>> ground, until after the throttle was turned to 0 and then
>>>> reapplied. 
> 
> How is your flight time compared to the lipos?
> What drone do you use?

I am using a modified Walkera Runner 250.
The unknown electric unicycle 18650 batteries won't work. That flight 
was extremely short/limited.

The bulky Dewalt 6 amp hour battery (not FLEXVOLT) uses 2 x5 rows of 3 
amp hour (26650 or close) batteries.

The Dewalt 5 amp hour battery uses 2 x5 rows of 2.5 amp hour 18650 
batteries (INR18650-25R). That's what I will try now, already have 3 
prepared and in the charger.

And they just drop into the battery holder.

If they don't work, I might order a battery holder for the bulky 
batteries. Not sure what they are, but they probably source more 
current than any of the others. I paid $75 for the battery pack with 
big, high current, and high capacity genuine batteries.

Dewalt now has 12 amp hour 20 V MAX batteries. I'm remaking my 
electric bike, I'll probably add some spacing so it can handle those. 
That's a whopping 24 amp hours carrying only one spare drill battery.







-- 

>>I am using ping-pong (table tennis) balls for skids. Much lighter at 
>>2.6 g each and should do well for skids since they are spherical,
> 
> Right, I had some larger balls planned for landing on water.
> If too big those steal air flow from the propelloers (in my case).
> 

They're charged!

On Saturday, November 10, 2018 at 4:05:34 PM UTC-5, John Doe wrote:
> <698839253X6D445TD@nospam.org> wrote:
> 
> > John Doe wroye
> 
> >>>> It flew! It flew! My battery pack stayed cool as a cucumber. At
> >>>> first, increasing throttle would not get the drone off of the
> >>>> ground, until after the throttle was turned to 0 and then
> >>>> reapplied. 
> > 
> > How is your flight time compared to the lipos?
> > What drone do you use?
> 
> I am using a modified Walkera Runner 250.
> The unknown electric unicycle 18650 batteries won't work. That flight 
> was extremely short/limited.
> 
> The bulky Dewalt 6 amp hour battery (not FLEXVOLT) uses 2 x5 rows of 3 
> amp hour (26650 or close) batteries.
> 
> The Dewalt 5 amp hour battery uses 2 x5 rows of 2.5 amp hour 18650 
> batteries (INR18650-25R). That's what I will try now, already have 3 
> prepared and in the charger.

If you mean there are 5 cells in series to make nominally 20 volts, then these are likely LiIon cells.  I don't know what you have 3 of in the charger.  Is that 3 cells, 3 strings or three battery packs? 


> And they just drop into the battery holder.
> 
> If they don't work, I might order a battery holder for the bulky 
> batteries. Not sure what they are, but they probably source more 
> current than any of the others. I paid $75 for the battery pack with 
> big, high current, and high capacity genuine batteries.
> 
> Dewalt now has 12 amp hour 20 V MAX batteries. I'm remaking my 
> electric bike, I'll probably add some spacing so it can handle those. 
> That's a whopping 24 amp hours carrying only one spare drill battery.

Rick C.

https://ts.la/richard11209 - Tesla referral code 

gnuarm.deletethisbit@gmail.com wrote: 

> John Doe wrote: 
>> <698839253X6D445TD@nospam.org> wrote: 
>> > John Doe wroye 
>> 
>> >>>> It flew! It flew! My battery pack stayed cool as a cucumber.
>> >>>> At first, increasing throttle would not get the drone off of
>> >>>> the ground, until after the throttle was turned to 0 and
>> >>>> then reapplied. 
>> > 
>> > How is your flight time compared to the lipos? What drone do
>> > you use? 
>> 
>> I am using a modified Walkera Runner 250. The unknown electric
>> unicycle 18650 batteries won't work. That flight was extremely
>> short/limited. 
>> 
>> The bulky Dewalt 6 amp hour battery (not FLEXVOLT) uses 2 x5 rows
>> of 3 amp hour (26650 or close) batteries. 
>> 
>> The Dewalt 5 amp hour battery uses 2 x5 rows of 2.5 amp hour
>> 18650 batteries (INR18650-25R). That's what I will try now,
>> already have 3 prepared and in the charger. 
> 
> If you mean there are 5 cells in series to make nominally 20
> volts, then these are likely LiIon cells.  I don't know what you
> have 3 of in the charger.  Is that 3 cells, 3 strings or three
> battery packs? 

The "INR18650-25R" is a lithium-ion cell.
I just took three batteries from a cordless drill battery pack.
Stuck them in my drone battery compartment and now I will go see if it 
flies.

Further response to the other reply.
Assuming it flies... Not sure about testing how long, yet. I just 
recently started flying non-GPS drones. I can barely fly my Rodeo 110 
around the yard. This will be my first flight with the (old model) 
Runner 250. 

Easier to fly than my Rodeo 110. Flew the Runner 250 for a minute or two 
until it started losing power. The batteries were not hot, but 
apparently their ability to source current diminishes quickly even 
though they remain charged. Reconnected and took off again, this time 
confidently applying throttle. It ZOOMED up so I dropped the throttle, 
then experienced the infamous "flip of death" (FOD). Messed up a 
propeller or two. That's enough testing for now.

With no load... The batteries started at 4.19 V. Now they are at 4.05 V. 

Apparently the Samsung INR18650-25R will not drive the Runner 250.