SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 16, 2014, 11:13 AM
Registered User
Canada, AB, Airdrie
Joined Oct 2014
47 Posts
Discussion
1S Lipo Questions

I am about to start building a MiMi for my first DLG and have been looking at the battery options. Lots of guys are running 1S Lipo in their DLG's and that looks like a good choice to me. I will be running a voltage booster to ensure my receiver keeps running (FrSky X4R, rated down to 4.0V minimum). I am returning to the hobby after years off and the Lipo's and super lightweight gear are all new to me. Some questions:

1) Are there some preferred capacities and brands for the batteries?

2) Does anybody use the round 1S types? Hobbyking has these:

http://www.hobbyking.com/hobbyking/s...ound_Lipo.html

Price is very cheap, capacity looks good and they are very light. I have never soldered leads onto a Lipo, though, so some pointers or a website with details on that operation would be very helpful.

If anybody wants to post details of their setups and/or pictures that would be appreciated.


Thanks,
Mark
mmattock is offline Find More Posts by mmattock
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 16, 2014, 11:25 AM
Registered User
elkski's Avatar
United States, UT, Sandy
Joined May 2013
3,173 Posts
Many of us are using that battery but in the 1200 mAh size. Most of our Rx's don't give a working range below 4 v but are working fine with no amp. Soldering is easy with a 15 w iron. You can see one of the flat solder leads in that image. 1200 runs for 4 hours on my DLG. I use a quad 120 600 of a different brand and it gives me an hour. A bit disappointing. Order extras as they do go out of stock and some have been known to be bad as new.
elkski is offline Find More Posts by elkski
Reply With Quote
Old Dec 16, 2014, 11:37 AM
Retirement is good
United States, CA, Huntington Beach
Joined Jun 2011
449 Posts
From a while ago I posted this. Hope it answers your questions.

http://www.rcgroups.com/forums/showp...3&postcount=22

Dick
rofly is online now Find More Posts by rofly
Reply With Quote
Old Dec 16, 2014, 11:49 AM
Registered User
United States, NC, Charlotte
Joined Mar 2014
93 Posts
I use the 900mah version of the HK round 1s cell in my full size DLG. With 4 digital servos, FrSky D4R-II Rx and FrSky Vario I use about 350mah during a 1 and a half hour flying session. I don't use the 1200mah version because with the 900mah I don't have to add any weight to balance my glider.

It's nothing special to solder a pigtail onto them like elkski said above.
Updraft67 is offline Find More Posts by Updraft67
Reply With Quote
Old Dec 16, 2014, 11:58 AM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,781 Posts
<- used the 1200, 1000, 900 and 650mah round as well as the 750 rectangular.

All worked well.

They're simple to solder and I usually charge frequently so capacity has never been an issue.

The 650s are my favorite but I charge about every 30 minutes of flying. I have gone an hour but I also have telemetry to tell me if I'm pushing it. So far so good.

All my stuff is digital everything.
tom43004 is offline Find More Posts by tom43004
Reply With Quote
Old Dec 16, 2014, 02:02 PM
Will fly for food
davidjensen's Avatar
Bellevue WA,
Joined Dec 2003
7,111 Posts
With the BTOA in, the voltage reports after an hour and a half were still over 4 v running a 750 flat cell
davidjensen is offline Find More Posts by davidjensen
Reply With Quote
Old Dec 16, 2014, 04:09 PM
Registered User
Canada, AB, Airdrie
Joined Oct 2014
47 Posts
Quote:
Originally Posted by elkski View Post
Most of our Rx's don't give a working range below 4 v but are working fine with no amp.
Good news. I will do some checking on that for the X4R I will be using before trusting it but it is good to know this is common.

Quote:
Originally Posted by rofly View Post
From a while ago I posted this. Hope it answers your questions.

http://www.rcgroups.com/forums/showp...3&postcount=22

Dick
Thanks for that, it was good to see how you set up yours. The soldering looks ok and I should be able to manage that.


Quote:
Originally Posted by Updraft67 View Post
With 4 digital servos, FrSky D4R-II Rx and FrSky Vario I use about 350mah during a 1 and a half hour flying session.
No booster? How does the D4R-II work on the single cell without a booster? I will be running two HXT-500 servos and an altimeter of some sort. 350mah for 1.5 hours of flying sounds perfectly reasonable to me. I don't expect to ever fly for more than two hours in one session and that leaves a decent cushion on the 650mah cell.


Quote:
Originally Posted by tom43004 View Post
The 650s are my favorite but I charge about every 30 minutes of flying. I have gone an hour but I also have telemetry to tell me if I'm pushing it. So far so good.
What does your telemetry give for usage in 30 minutes of flying?


Quote:
Originally Posted by davidjensen View Post
With the BTOA in, the voltage reports after an hour and a half were still over 4 v running a 750 flat cell
Excellent news.


I have one more question - is there a preferred connector for the battery or do most of them work ok? Any to be avoided?


Thanks,
Mark
mmattock is offline Find More Posts by mmattock
Reply With Quote
Old Dec 16, 2014, 04:47 PM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,781 Posts
I use the X4R with vario and four digitals... typically after 30 minutes of flying I'm at somewhere around 4.08-4.1v and after an hour of flying I'm still at 4.0.

It takes a while to trip my alarm, which I have set at 3.9v... still well north of the shoulder for 1S lipo
tom43004 is offline Find More Posts by tom43004
Reply With Quote
Old Dec 16, 2014, 11:35 PM
Will fly for food
davidjensen's Avatar
Bellevue WA,
Joined Dec 2003
7,111 Posts
I use Deans mini connectors
davidjensen is offline Find More Posts by davidjensen
Reply With Quote
Old Dec 17, 2014, 10:52 AM
Registered User
Milton Keynes, UK
Joined Oct 2005
1,199 Posts
Rather than using any nose-weight, I have 2P setup of the 1000mah round lipo giving me a 2000mah capacity

I charge the model at the beginning of the week and fly for an hour every lunch time.

No voltage booster
- d47 and ds-09 servos
FrSky D4R-II Rx home-made openxsensor altimeter

by the end of the week I am at 3.9V

the telementry logs show voltage never drops more than 0.1V under load
Richard S is offline Find More Posts by Richard S
Reply With Quote
Old Dec 17, 2014, 11:06 AM
Quacker's Avatar
United States, CO, Longmont
Joined Jul 2001
2,836 Posts
I'm running 2 of the 650maH round cells in parallel and they have been reliable. I've selected and tested my gear to be able to run on a almost dead 1S without a voltage booster. The reason is that there really is no room for a booster in my Snipe, and I could not find a booster that had enough peak current to prevent brownout if both my flaperon servos stalled by a sudden full deflection at a high airspeed.

Receiver: AR6255
Servos: 4 x DS285

With a system idle current of 60ma, I can leave the thing turned on all day and not worry.
Quacker is offline Find More Posts by Quacker
Site Sponsor
Reply With Quote
Old Dec 17, 2014, 12:46 PM
A different attitude to RC
extremewing's Avatar
Draper, Utah
Joined Sep 2008
2,790 Posts
More info on my use of 1s: http://www.rcgroups.com/forums/showthread.php?t=2169558
extremewing is offline Find More Posts by extremewing
Reply With Quote
Old Dec 18, 2014, 01:54 PM
Registered User
San Diego
Joined Aug 2004
2,328 Posts
Does anyone have a discharge curve for the 900 or 1200 round lipo? I'm curious as to what the curve looks like at a constant 1 or 2 amp draw.

Thanks!
Tom
Kiesling is offline Find More Posts by Kiesling
Reply With Quote
Old Dec 18, 2014, 02:35 PM
Retirement is good
United States, CA, Huntington Beach
Joined Jun 2011
449 Posts
Quote:
Originally Posted by Kiesling View Post
Does anyone have a discharge curve for the 900 or 1200 round lipo? I'm curious as to what the curve looks like at a constant 1 or 2 amp draw.

Thanks!
Tom
Tom, lots of curves with a "lithium polymer battery discharge curve" Google search, but nothing specific to your question. With a saturation charge at 4.2V with the 1200 round I put back about 600 mA using a 3.7V Tx warning while stirring the sticks at a rate of about 160 mA per hour, for nearly 4 hours of flying.. not very useful data for you.

At 15C rated continuous discharge that battery should handle 2 amps easily, but I will always recommend a 3.7V cutoff (when first observed) both for headroom safety and servo speed. I regard Rx voltage telemetry as non-optional for the same reason.

Dick
rofly is online now Find More Posts by rofly
Reply With Quote
Old Dec 18, 2014, 03:58 PM
Registered User
David Forbes's Avatar
United States, FL, Gainesville
Joined Dec 2005
2,913 Posts
Note that the HK 1200 round cells are not as robust as the little 2s LiFe that I was using in my last fuse. Change these out yearly, they are cheap. I let one sneak up on me, realized I had had it in service over two years (easy for us who have a year round season).
It still took it's usual 250 to 300mA after a flying session, but voltage sag was severe enough that when I pulled flaps, the DS285s on R+E browned out. The symptom was that my elevator compensation would not kick in until the cells recovered a bit and the plane would balloon.
Had us scratching our heads for a while. Fortunately no issues with the ATX Rx or 94802s in the wing.

Dave
David Forbes is online now Find More Posts by David Forbes
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion I have a question about 1s nano qx lipos help! spencer911 Mini Multirotors 25 Dec 17, 2014 09:57 AM
Discussion I have a question about these 45c 1s 150mah lipos for my nano qx help! spencer911 Mini Multirotors 4 Dec 14, 2014 01:25 PM
Discussion 1s LiPo charging question Kombatkarl Batteries and Chargers 3 Aug 03, 2014 09:34 PM
Discussion 1s lipo questions Ja9 Hand Launch 36 Dec 09, 2013 10:20 PM
Sold eflite 3.7v 1s 120mah lipo's tenergy 3.7v 1s 130mah lipo's nitrodude71 Aircraft - Electric - Batteries & Chargers (FS/W) 2 Nov 17, 2010 01:05 PM