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-   -   A123 Question (https://www.rcuniverse.com/forum/batteries-chargers-84/11200481-a123-question.html)

RCP57 08-20-2012 08:42 PM

A123 Question
 
Finally getting back into the hobby after two years and the battery technology has changed quite a bit. What is the hot ticket for giant scale airplanes? Need to put some new batteries in my 35% YAK w/da 100 motor. The A123 batteries seem to be the newest technology but has anyone come up with a way to check them? Or do I need to look in another direction like Lithium Ion w/regulators?

Goldenduff 08-20-2012 09:38 PM

RE: A123 Question
 
Can you please clarify what the battery will power? Thanks

Rocketman_ 08-21-2012 02:46 AM

RE: A123 Question
 
Lithium Ion w/regulators.

BarracudaHockey 08-21-2012 04:32 AM

RE: A123 Question
 
You don't so much "check them" as fly them a couple of times and get an average consumption per flight. Then figure out a safe number of flights with a safety margin and charge after that number of flights.

With my 50cc stuff I charge and fly 4 flights. Thats 6 big servos and an ignition. I get 4 flights and put 60 percent of the capacity back in.

No regulators, no self discharge, no downside.

snir2001 08-21-2012 05:01 AM

RE: A123 Question
 
A123 (Genuine) are the best for you, just check the consumption per flight as BarracudaHockey post, and than use the right capacity.

jackalope54 08-21-2012 05:06 AM

RE: A123 Question
 
RCP57 -

I couldn't agree more with BarracudaHockey. I switched to A123 packs (from Nimh) in February of this year - 2300 mah packs from Radical RC. No regulators on my Futaba 2.4 ghz receivers - 5 S3152 digital Futaba servos (87 oz/in) and 1 analog servo in each plane. Being new to this chemistry, I flew once and recharged (at 1C) at the field - found I only used about 120 ma. This consumption has remained fairly consistent.

I have since installed a Hyperion 2100 mah LiFe battery in my Futaba 10C radio (huge upgrade from the 700 mah NiCads it came with) and am completely sold on this application as well.

Best thing since sliced bread. :)

Jack

P-51B 08-21-2012 06:13 AM

RE: A123 Question
 
Are A123 and Lithium Iron Phosphate (LiFe) the same? I have seen references to different LiFe chemistries and just want to confirm for charging purposes since my charger has a A123 setting but not a "LiFe" setting.

BarracudaHockey 08-21-2012 06:51 AM

RE: A123 Question
 
Yup, A123 is a brand name for LiFe chemistry batteries sold by A123 systems.

Kind of like saying Tylenol or Acetaminophen

True A123 cells really are better than some of the "LiFe" batteries floating around the market though.

DadsToysBG 08-21-2012 08:31 AM

RE: A123 Question
 
I put three flights on my plane last Sunday. When I go this coming Sunday won't have to charge in the morning. After three more hit with 5amps and go fly again. Dennis

dirtybird 08-21-2012 10:10 AM

RE: A123 Question
 
A123's are refined LIFE'S. The main difference is A123's are tolerant of much higher charging and discharge rates than LIFE's. This make them ideal receiver batteries. The problem with A123's is they are only sold in two sizes.

Charlie H. 08-21-2012 12:01 PM

RE: A123 Question
 
Hi
I'm new to A123 technology too, do you have to balance the pack ? Plan on powering a JR receiver, would like to be able to leave the packs in the plane during charging.

Thanks
Charlie

BarracudaHockey 08-21-2012 12:36 PM

RE: A123 Question
 
A good charger like a Cell Pro will balance it every charge. Yes they should be balanced but in low draw applications like rx's they tend to stay in pretty good balance.

Again, charging in the plane is no issue. Call WrongWayRC, he can make you external balance charge jacks etc.

Hill202 08-21-2012 01:33 PM

RE: A123 Question
 
I use A123 batteries as well. I just started using them this flying season. I'm very pleased with their performance. They are very reliable. It does not take long at all to figure out how much you use per flight. I barley keep up with it any more. I know, based on my flying style, just when it's time to charge.

All Day Dan 08-21-2012 06:26 PM

RE: A123 Question
 
Barracuda, how do you monitor your A123 batteries for capacity? Every battery degrades over time and it is always prudent to know your battery’s capacity prior to reaching its failure point. Dan.

Termites Dream 08-21-2012 08:39 PM

RE: A123 Question
 
Question: how many years do you expect to get out of your A123s? Or LiFEs?

I have Li Ions on a 110 inch EF yak and a 55cc Aeroworks extra, Li Ions are 2-3 years old and am thinking of switching to the A123s. Extra battery cost and cost of new charger (if the Hitec X4 is not up to task) would be justified if the A123s last more than a couple of years. Might also switch other gassers and a couple of glow planes over to lifes (from NiMH) over time. Will need some ignition regulators, what do you guys use?

Thanks for the info in this thread, helps a lot.

David

Rocketman_ 08-21-2012 10:26 PM

RE: A123 Question
 
I've continued to use Lithium-ion batteries because monitoring their capacity is a quick and simple procedure that can be performed with the voltmeter in my field box. Lithium-ions are reliable, lightweight, have good longevity and are safe to charge in the plane. Remember, many electronic devices that we use in our homes have Lithium-ion batteries such as cameras, laptops, phones, universal remote controls, iPads, etc., etc. and the batteries are charged without removing them.

I never have to charge at the field because I never have to guess how much of the charge remains as one has to do with A123 batteries. A123 batteries are great for DeWalt power tools since there won't be a disaster when the battery suddenly quits.

By the way, A123 Systems Inc. has failed because they were turning out bad batteries. They will go completely out of business if the government rejects the huge bail out offer by a Chinese company. Who knows, you may be using some good Chinese batteries soon

BarracudaHockey 08-22-2012 05:04 AM

RE: A123 Question
 
Sorry but that is simple misinformation. The division of A123 systems that makes model and drill batteries is different than that making the car batteries that is having issues and involved in the govt bail out over there.

Dan, thinking of trading in your 8 track? :D
http://www.hangtimes.com/a123_batter...iants_faq.html


Will need some ignition regulators, what do you guys use?

About half way down this page
http://www.shop.kavarootusa.com/cate...?categoryId=10

grizzly59 08-22-2012 06:16 AM

RE: A123 Question
 

ORIGINAL: Rocketman_

Lithium Ion w/regulators.

+1

I use two 5200 mah packs in a 35%er. I fly 4 flights in one day and go back to the field and fly 4 more the next day and still have power for a few more flights. Grant you I am not a tear it up heavy duty 3D guy. I can also check the battery at the field and know exactly when I need to charge. I will charge the batteries and go flying a month later and have enough power in the batteries to fly with no worries due to the very slow self discharge rate. I got Lithium Ions because I hated charging at the field when we were all using MiMH's. Can't understand why there is such an issue in some hobbyists about using a regulator. Seems 123's became popular when the Lithium Ions were hard to get due to factory issues in China a few years back and guys started tearing up drill packs. I see too many guys posting on the flying sites about their wrecks and seeing 123's listed as part of their equipment. Still can't figure out the advantage of 123's but the old saying goes "to each his own".

All Day Dan 08-22-2012 07:29 AM

RE: A123 Question
 
Thank you Mr. Moderator. What I was looking for was some kind of data that discusses the life expectancy of the A123 batteries or some way that the average RCer can determine that his batteries are approaching their end of life. I know the guys at my field usually wait until that happens and, as expected, it does was they are flying. That long missive you sent me to does not discuss it nor do I know who the author is or what his qualifications are to even discuss it. Do you know of any test data that can tell us when those batteries are going to fail or how to determine when a pack is coming to its end of life? Dan.

PS, No, I'm sticking with the eight track.

dirtybird 08-22-2012 07:33 AM

RE: A123 Question
 
The advantage I have found with A123's is you dont have to baby them.
I get my batteries from China. They are better than the ones I got out of a DeWalt pack.

dirtybird 08-22-2012 07:40 AM

RE: A123 Question
 


ORIGINAL: All Day Dan

Thank you Mr. Moderator. What I was looking for was some kind of data that discusses the life expectancy of the A123 batteries or some way that the average RCer can determine that his batteries are approaching their end of life. I know the guys at my field usually wait until that happens and, as expected, it does was they are flying. That long missive you sent me to does not discuss it nor do I know who the author is or what his qualifications are to even discuss it. Do you know of any test data that can tell us when those batteries are going to fail or how to determine when a pack is coming to its end of life? Dan.

PS, No, I'm sticking with the eight track.
You can tell if the battery is coming to the end of life by cycling them.
I made a fake radial engine from 10 cells. In the beginning it would power my Lazy Ace 6 minutes. After about 400 flights I could get barely 4 minutes.

DadsToysBG 08-22-2012 07:59 AM

RE: A123 Question
 
I had one A123 that was 6 years old before it wouldn't cycle to 80%. I cycle my batterys in the spring. Dennis

chuckk2 08-22-2012 08:09 AM

RE: A123 Question
 
Then the LiFe batteries are NOTA123 batteries.
A123 is both a brand and a patented battery design. Sadly, A123 is in financial trouble, much as the solar panel Mfrs are.
I believe the genuine A123 batteries(a good one, that is) have a longer life than the Chinese LiFe batteries. The DeWalt batteries
are likely "low bidder" batteries.

Decades ago, Sears came out with lantern batteries that had extremely low resistance, and if shorted, did things like catching on fire or exploding.
Recall time! Then, vents and fuses were added, and eventually auto resetting fuses. They may have been an early form of NiCads.


ORIGINAL: dirtybird

The advantage I have found with A123's is you don't have to baby them.
I get my batteries from China. They are better than the ones I got out of a DeWalt pack.

BarracudaHockey 08-22-2012 08:13 AM

RE: A123 Question
 
First, my name is Andy or Andrew. Andy Griffith in fact. My name isn't Mr Moderator, nor do I moderate anything but the helicopter forums. In the gas, giant scale, and any other forums I participate in I'm just a user like anyone else. I have no problem with the jabs back and forth, you and I do things differently, I acknowlege and respect your opinion and I refer to you as Dan even though we do have our own way of doing things. As for me, as you can see from my AMA number, I'm neither a kid or a newb, I've been doing this a while. Though admittedly my profession (computer network engineer) means my personality leans towards playing with the newest toys like A123's, 2.4 technology, etc.

Yes, you can cycle LiFe or A123 batteries like any other chemistry to determine capacity.

They don't benefit from cycling like Nickel based batteries but it will tell you capacity.

The link I posted is a FAQ by a well known and respected battery supplier. If WrongWay wasn't a Florida guy that is pleasant to deal with I'd get my stuff from Hang Times.

chuckk2 08-22-2012 08:24 AM

RE: A123 Question
 


ORIGINAL: All Day Dan

Thank you Mr. Moderator. What I was looking for was some kind of data that discusses the life expectancy of the A123 batteries or some way that the average RCer can determine that his batteries are approaching their end of life. I know the guys at my field usually wait until that happens and, as expected, it does was they are flying. That long missive you sent me to does not discuss it nor do I know who the author is or what his qualifications are to even discuss it. Do you know of any test data that can tell us when those batteries are going to fail or how to determine when a pack is coming to its end of life? Dan.

PS, No, I'm sticking with the eight track.
The test data for a particuliar battery pack is obtained by discharging a pack to the safe discharge voltage, recharging it, discharging it again, and keeping track of the charge and discharge. You also have to look at the battery specs. A good charger will charge to a specified capacity, along with time, temperature,voltage, current, and so forth, and with A123's it may allow a trickle or "float" charge after a normal charge is complete.
If you have the capability to do so, you can also look at voltage vs discharge rate. As batteries age, internal resistance goes up, and the voltage tends to drop more at high discharge rates.


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