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Author Topic: 2200mAh 3S 20C Lipo Pack have you used one?  (Read 3714 times)
AK0B
Member

Posts: 267




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« on: April 15, 2017, 08:44:57 PM »

I wonder if anyone has tried the 2200mAh 3S 20C Lipo Pack with a QRP transmitter.  If so what were the results. I have checked the review section and was not able to find anything.

This is a 11.1 vdc battery often used in radio control projects.

I use the older style batteries 12v 7.5 Ah like used alarm systems and it weighs over 5 lbs.  It works great if a park bench is close to the parking lot.

I am interested in how many ma I can draw from a Lipo battery pack for how many operating hours before it drops to 9.5 vdc.  My DIY transmiters, etc usually draw 300 or so ma 

Thanks, Stan AK0B


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KU3X
Member

Posts: 411




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« Reply #1 on: April 16, 2017, 05:46:26 AM »

That's all I use anymore. I gave away my 12v @7ah gel cell.
http://www.ku3x.net/portable-qrp/elecraft-kx3

Scroll down to the bottom of the page and you'll see. My go to LiPo is the 3000 mah, I use it with my KX2, KX3 and both of my YouKits
QRP radios. The KX2 has an internal LiPo rated at 2600 mah but I carry along the 3000 mah for backup. With the KX3, the internal
batteries don't have the higher voltage provided by LiPo's so I take my 4000 mah battery with me if I plan on a long day in the park.
LiPo's offer more current for their size and hold a charge longer sitting on the shelf. It's the only way to go.

Barry
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KB1GMX
Member

Posts: 1496




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« Reply #2 on: April 16, 2017, 02:14:14 PM »

I use 2800, 5600, 11,000mah lipo packs for a my Radios such as FT817, Argo 505
several home brews that were designed for 12.6 nominal..  Those are 1/2/4 cell by 3
18650 cells (LG 2800mah parts) with battery protect circuit boards as part of the pack.

The FT817 find 11.1 to be ideal.  The other radios like the Argo were designed for 13.8V
so they run at reduced power (4W rather than 5W).   THe homebrew run ok with no issues.

the big thig is what voltage does the radio start to fade or have issues.  THe FT817 runs
well below 10V  Others don't like that.

FYI a nominal 11.1V pack is more like 11.4 fully charge (or 12.6 depending on chemistry)
and the near exhausted voltage is about 8.7V minimum.  I use LiPO and the full charge
votlage is 12.6 and cutoff is 8.8V and that works fine for the FT817.  I have a few LiFePo4
and they have a lower full charge voltage and run down a bit power 11.4 and 8.7V which
works for the  Ft817.  For the rest that want higher voltages I built a high efficiency boost
regulator to give nominal 13.8 to keep them happy (note its heavily shielded and filtered).
Or I use 4 cell packs (16.8V full charge).

I'm generally happy with Lithium tech but take care with charge and discharge or poof.

Allison
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KU3X
Member

Posts: 411




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« Reply #3 on: April 17, 2017, 01:53:13 PM »



I'm generally happy with Lithium tech but take care with charge and discharge or poof.

Allison

I could not agree more. I always use a charging bag and ALL batteries are stored in a metal ammo box I purchased from Dicks Sporting
Goods.
I have my KX3 and KX2 to stop working at 9.2 volts. That offers me plenty of operating time since all of my LiPo's full charge is well
above 12 volts.
Both the KX rigs have a voltmeter you can display on the screen. That makes it nice to know the status of the batteries.

Barry
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N6PG
Member

Posts: 200




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« Reply #4 on: April 17, 2017, 07:49:32 PM »

I wonder if anyone has tried the 2200mAh 3S 20C Lipo Pack with a QRP transmitter.  If so what were the results. I have checked the review section and was not able to find anything.

This is a 11.1 vdc battery often used in radio control projects.

I use the older style batteries 12v 7.5 Ah like used alarm systems and it weighs over 5 lbs.  It works great if a park bench is close to the parking lot.

I am interested in how many ma I can draw from a Lipo battery pack for how many operating hours before it drops to 9.5 vdc.  My DIY transmiters, etc usually draw 300 or so ma 

Thanks, Stan AK0B




I use 2200mAh 3S 20C Lipo all the time. It's a great size for a lot of QRP battery.
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AK0B
Member

Posts: 267




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« Reply #5 on: April 17, 2017, 11:46:37 PM »

Thanks fellows.  I am going to try my luck also. 

Stan ak0b
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AK4YH
Member

Posts: 32


WWW

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« Reply #6 on: April 18, 2017, 03:26:09 AM »

They work fine but you need to monitor voltage very closely. I have destroyed a few 3S packs by not paying attention. It gets expensive... These days I use a voltage alarm set to 3.2V.

Gil.
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N6PG
Member

Posts: 200




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« Reply #7 on: April 19, 2017, 06:28:34 AM »

$20 LiPo battery checker will show voltage and a %. It plugs into the balancer plug on the LiPo. Don't go below 30%

Or you can use a voltage alarm set at whatever voltage you want. Check eBay, Amazon, or local RC hobby store.
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KB1GMX
Member

Posts: 1496




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« Reply #8 on: April 21, 2017, 10:56:01 AM »

For radio use I prefer to use packs with battery protection boards
or with charge and battery protection boards.    The flying model
and drone people do not use them as its weight and may impact
power delivery but for radio use where drain is moderate to low
and the time of use is more important they can protect the battery
from insults that may lead to an energetic failure (poof).

Those board can also insure you do not over drain the cells, provide
short circuit protection and excessive charge Voltage protection.
For Lithium chemistry batteries its good  for safety and cost as
good quality batteries aren't cheap.

The real problem every time is the average voltage during discharge
suitable for the radio in question.  Some radios need at least 11.7V
or higher to work right other like the Ft817 and KX2/3 are fairly tolarent
to under 10V.  Like it or not all batteries have decaying voltages as they
discharge that limit the useable capacity, what they can deliver vs what
you can actually use.  Example LiFePo4 are still around 50% when
at 3.1V per cell and for a 3s pack that's 9.1V few radios perform well
at that voltage.  A 4S pack sounds good hen but the full charge voltage
for that chemistry is  14.8V (maybe higher for some brands). An example
of the LiPo that have a full charge voltage of 4.2V (some are 4.35V)
and a 4S pack is around 16.8V which is too high for a great many radios.
Its important to be very specific as to what lithium chemistry is being
discussed or the results may not match.

In the end its about weight and how much time you need to operate.

But like I've said earlier, my results have been excellent with a handful
of radios I have that tolerate the voltages provided.  I also have multiple
packs of different voltages that best match the radio generally using 18650
cells in 3S or 4S form with battery protection and charge management.

I use a lower cut off (3V) for LG 2800mah and Panasonic 2200mah
18650 cells and have not killed any on many years of use.   According
to the data sheets those cells can go as low as 2.7 safely.   Most of
the batteries used are now in excess of 100 cycles  of use and still
better than 95%.   Also I have a 1p4S pack of Panasonic 1800mah
18650 cells removed from a 1998 laptop that died back around
2004 and are still going strong.   I prefer cells that I can get full
vendor data on.

The 20C number means the pack will deliver at 20 times the capacity
without overheat or interconnect burn out failure (44A) obviously
for only a short period of time (maybe 2.5 to 3minutes).   For a
sub 1 Amp load its meaningless.  For a quadcopter hovering its
important.  More importantly without protection (fuses, polyfuse
or battery protection board) that battery can burn up heavy wires
if shorted as it can dump an immense amount of power in a short
time.

NOTE: Stan, for a radio that will work to 9.5V and peaks 300ma should
run very well for a good while off a 3S 2200ma pack. If I assume a
50ma rx and QRP ops (less than 25% tx time) the life is in days.
Worst case is brick on the key and likely more than 6-8 hours to
exhaustion. Its a lot of power for very little weight.


Allison
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KJ6DRG
Member

Posts: 78




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« Reply #9 on: April 23, 2017, 08:49:22 PM »



I'm generally happy with Lithium tech but take care with charge and discharge or poof.

Allison

I could not agree more. I always use a charging bag and ALL batteries are stored in a metal ammo box I purchased from Dicks Sporting
Goods.
I have my KX3 and KX2 to stop working at 9.2 volts. That offers me plenty of operating time since all of my LiPo's full charge is well
above 12 volts.
Both the KX rigs have a voltmeter you can display on the screen. That makes it nice to know the status of the batteries.

Barry
Barry,
Where did you get the mount for the Pico Paddle on your KX3? I am about to order the radio and already have the paddle and your setup looks great!
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KJ6DRG
Member

Posts: 78




Ignore
« Reply #10 on: April 24, 2017, 05:17:28 AM »



I'm generally happy with Lithium tech but take care with charge and discharge or poof.

Allison

I could not agree more. I always use a charging bag and ALL batteries are stored in a metal ammo box I purchased from Dicks Sporting
Goods.
I have my KX3 and KX2 to stop working at 9.2 volts. That offers me plenty of operating time since all of my LiPo's full charge is well
above 12 volts.
Both the KX rigs have a voltmeter you can display on the screen. That makes it nice to know the status of the batteries.

Barry
Barry,
Where did you get the mount for the Pico Paddle on your KX3? I am about to order the radio and already have the paddle and your setup looks great!
Nevermind. I should have Googled first! Thanks anyway.
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AD0AR
Member

Posts: 112




Ignore
« Reply #11 on: April 29, 2017, 10:05:25 PM »

After trying lead acid batteries, like the 35ah AGM battery from Harbor freight and finding them to be quite inferior I finally set my mind to try a LiFePO4 battery from Bioenno power.  Excellent company, they even have hams working for their sales department so they are knowledgeable too.
  I purchased a 50AH battery- weight is about 15 pounds.
I'm not running QRP, I'm using a Icom IC-7100 at full power.  I love the power curve.  Having 600 watt hours at your hands in a portable setup feels like you are not running on battery power.  It is nice to set and forget.  The radio puts out full power to about 11.5 volts and then well... you have used about 600 watt hours.
  Output sits around 13.4v until about 60-70% capacity has been used then as one approaches empty it will slowly drop until auto protect shutoff at 10.8v. 
I know this is a little bigger than some small cells, but still amazing technology if you can afford it.
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