HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 16, 2012, 07:02 AM
Registered User
ritchie_laird's Avatar
Australia, VIC, Craigieburn
Joined Jul 2012
222 Posts
Quote:
Originally Posted by lovegroove View Post
Why not enter my halloween competition and then you can win a controller. Your copter doesn't have to be flying to be able to win!!!!
PM sent.
ritchie_laird is offline Find More Posts by ritchie_laird
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 16, 2012, 07:20 AM
Registered User
zacker's Avatar
United States, CT, Oxford
Joined Oct 2012
51 Posts
Quote:
Originally Posted by lovegroove View Post
I used to have range check on my pre-flight, but haven't found a good way of doing a range check with a multicopter.
fly it as far as possible till it crashes then measure the distance?
lol,lol...

Hey, what happens when it goes out of range anyway? will it just stop working and fall to the ground?

I can guess my range would be "when its too hard for me to see it, its OOR!"
zacker is offline Find More Posts by zacker
Reply With Quote
Old Oct 16, 2012, 07:32 AM
http://drone-pilot.blogspot.fr
lovegroove's Avatar
Rhone Alps, France
Joined Aug 2008
2,540 Posts
If you have your failsafe set correctly then when it goes out of range it should descend quite rapidly and crash. If you don't have it set correctly then it just keeps going until it falls out of the sky when the batteries die.

I once managed to hit throttle lock just after take off at about 3/4 power and because it all happened so quick I couldn't work out what was happening. It just started gaining altitude so quick and then got caught in the wind. I chased after it for a while, but eventually I realised I was going to have a fly away, so waited until it was in a safe place and just turned the tx off and watched it drop. Amazingly I didn't suffer too much damage to the copter and much better than having a fly away copter and not knowing where it might come down or what it might hit.
lovegroove is offline Find More Posts by lovegroove
Reply With Quote
Old Oct 16, 2012, 07:43 AM
Registered User
Japan, Tokyo, Chiyoda
Joined Oct 2010
239 Posts
nice blog and articles

idea for article ? why not how to handle, charge, use, and store batteries ? maybe you can avoid a few lipo fires in people's homes
alainphoto is offline Find More Posts by alainphoto
Reply With Quote
Old Oct 16, 2012, 07:59 AM
Registered User
ritchie_laird's Avatar
Australia, VIC, Craigieburn
Joined Jul 2012
222 Posts
I have to agree with you, as people use safe practice on there lipo's noobies are not aware of the dangers and it should be repeated continually to let them know as sellers don't relay the dangers when selling them. sellers assume everyone knows the dangers. and they don't


Quote:
Originally Posted by alainphoto View Post
nice blog and articles

idea for article ? why not how to handle, charge, use, and store batteries ? maybe you can avoid a few lipo fires in people's homes
ritchie_laird is offline Find More Posts by ritchie_laird
Reply With Quote
Old Oct 16, 2012, 08:04 AM
Registered User
Japan, Tokyo, Chiyoda
Joined Oct 2010
239 Posts
I guess if you ask to new comers how much they can charge a 3s, and about how long this should take with their charger, probably half of them have no idea. But that's really something they should know before burning their family down ... etc etc
alainphoto is offline Find More Posts by alainphoto
Reply With Quote
Old Oct 16, 2012, 08:10 AM
Registered User
ritchie_laird's Avatar
Australia, VIC, Craigieburn
Joined Jul 2012
222 Posts
4 years experience with Lipo's and I could not tell you. I just hook them up set the charger and wait for it to tell me when its finished. keeping an eye on the lipo from time to time in case it starts to swell. but in saying that I still have a bucket of salt water in the garage in case the worst should happen.

if you asked a newbee what should they do if a lipo starts to swell, what should they do. salt water is probably the last thing they would think of.


Quote:
Originally Posted by alainphoto View Post
I guess if you ask to new comers how much they can charge a 3s, and about how long this should take with their charger, probably half of them have no idea. But that's really something they should know before burning their family down ... etc etc
ritchie_laird is offline Find More Posts by ritchie_laird
Reply With Quote
Old Oct 16, 2012, 08:14 AM
Registered User
Japan, Tokyo, Chiyoda
Joined Oct 2010
239 Posts
I did not know for the salt water

well lovegroove you have your article idea now
alainphoto is offline Find More Posts by alainphoto
Last edited by alainphoto; Oct 16, 2012 at 08:32 AM.
Reply With Quote
Old Oct 16, 2012, 08:16 AM
You Enjoy Myself
United States, NC, New Bern
Joined Jul 2012
77 Posts
I'm careful about charging my 3s LiPo's but don't store them in bags. I will get some soon.

I have an intelligent battery charger. When I charge my batteries, in regular charge mode, it usually takes about an hour maybe a little less to fully charge them. From what little reading I've done on charging batteries specifically, most of the times for a full charge I saw were much less.

Am I doing something wrong?

3s, 30c, 2800 mAh, 11.1 v


I've also seen people debate balancing batteries while charging, or balancing while not charging. Is there a consensus about this? What's the best way to charge/balance LiPo's?
cwg25 is offline Find More Posts by cwg25
Reply With Quote
Old Oct 16, 2012, 08:30 AM
Registered User
Japan, Tokyo, Chiyoda
Joined Oct 2010
239 Posts
cwg25 : take a look here :
http://www.rcgroups.com/forums/showthread.php?t=209187
especially, post #4 with the example of mistakes

okay, that's along article, that's why a more simple one would be nice


another idea of article : how to choose some proper props, both in term of quality and efficiency (characteristics)
(not to have the ultimate perfect fit, but at least to do the 20% optimization that gives 80% of the efficiency ...)

personally I am still confused about that one
alainphoto is offline Find More Posts by alainphoto
Last edited by alainphoto; Oct 16, 2012 at 08:40 AM.
Reply With Quote
Old Oct 16, 2012, 08:47 AM
Stop me before I build again!
United States, NY, Albany
Joined Sep 2012
1,320 Posts
I think a lot of battery confusion comes from the labeling. 20C, 50C, ... it's all just a little math and might help people understand why the batteries pack a punch. My 4Ah 40C battery can safely output it's whole charge at 40C ( 1/40th of an hour / 90 seconds ) at 160 amps ( 4 * 40 ) or 1700 watts! This is in par with a toaster oven or microwave. So even outputting at it's rated capacity it can easily output enough energy to start a fire and shorted out it can discharge much quicker and will probably cause the battery to self destruct.

Charging a battery at it's rated capacity, presuming you have run it low, should always take an hour give or take. For example 2.8 Amp hour battery charged at 2.8A(1C) should take an hour :-), but in reality a smart charger dials down the amperage as it get close to full so it may take longer. If you have the balancing plugs, use them whenever possible, it should not be any faster or slower than a regular change.

Quick charges are when you charge at faster than 1C, some batteries can charge faster and that will proportionally reduce your charging time. So charging at 2C will approximately cut your charging time in half. Only do this if the manufacturer has stated that it is safe and it will reduce the lifetime of the battery.

If charging takes a lot less than an hour then you are either leaving a lot of capacity in the battery, which can extend the lifespan, or charging them at higher than 1C.

As to my question earlier I will be picking up a parallel board so I can safely charge 2x 3s batteries at a time as a virtual 6s pack with the balancing leads connected. I will probably only use this occasionally to reduce the lag between flight sessions on a nice day. I will also be setting up a dedicated location in the house with a fire extinguisher and proper heat shielding in case the worst should occur. I will also be throwing a fire extinguisher into my flight bag.
brontide is offline Find More Posts by brontide
Reply With Quote
Old Oct 16, 2012, 08:48 AM
http://drone-pilot.blogspot.fr
lovegroove's Avatar
Rhone Alps, France
Joined Aug 2008
2,540 Posts
Your Lipo should have written on it the max safe charging rate. This is usually 1C or 5C and it works a bit like the maximum discharge 'C' ratings. What this means is that if you have a 2200mAh lipo rated at 1C charge then you should charge it at 2.2A and it will take about an hour. The same battery rated at 5C charge can be charged at 11A and should take about 12 minutes, although in reality it's a bit longer than this because the charge rate drops off towards the end of the charge cycle.

On my Lipos that can be charged at 5C, I charge them four times at 5C and then I do a 1C charge on them. Doing it this way seems to keep them going for lots of cycles, but there may be better ways out there.

Nowadays there's no reason not to do a balanced charge, as almost everyone has a smart balance charger. I think a lot of this talk comes from when Lipos were new on the market and people were charging them with old fashioned NiCad or Nimh chargers that didn't have the balance port.
lovegroove is offline Find More Posts by lovegroove
Reply With Quote
Old Oct 16, 2012, 08:59 AM
Stop me before I build again!
United States, NY, Albany
Joined Sep 2012
1,320 Posts
Doh, for the price of the balancing board and cabling hassle I should probably just splurge on a second ( or third ) charger. This will give me far more flexibility in charging.

When in doubt charge at 1C ( regular charge ).
brontide is offline Find More Posts by brontide
Reply With Quote
Old Oct 16, 2012, 09:00 AM
Registered User
Japan, Tokyo, Chiyoda
Joined Oct 2010
239 Posts
I have a third article proposal, after batteries and props; FPV for noobs/intermediate/blow-the-budget with a shopping list
alainphoto is offline Find More Posts by alainphoto
Reply With Quote
Old Oct 16, 2012, 09:03 AM
http://drone-pilot.blogspot.fr
lovegroove's Avatar
Rhone Alps, France
Joined Aug 2008
2,540 Posts
Quote:
Originally Posted by alainphoto View Post
I have a third article proposal, after batteries and props; FPV for noobs/intermediate/blow-the-budget with a shopping list
Nice, I will make a start on this one! Cheers!
lovegroove is offline Find More Posts by lovegroove
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Do you know what airplane is this and who made it? mashca Vintage & Old-Timer Designs 11 Sep 13, 2012 11:43 PM
Discussion Do you know what airplane is this and who made it? mashca The Builders Workshop 5 Sep 11, 2012 07:05 PM
Question How do you know what part is bad? j2591 Micro Helis 5 Aug 13, 2012 07:39 PM
Discussion Do you know what this is? jaizon Thermal 3 Jul 22, 2012 02:09 PM
Wanted do you know what plane this is ? streetbikegod4 Aircraft - Electric - Airplanes (FS/W) 5 Mar 18, 2012 08:41 AM