RE: A123 Question
 

Thanks Andy and everyone else. No one had mentioned cycling A123 batteries before to determine their capacity so it was hard to tell if it could be done. Are there any cyclers out there? Do you just cycle the entire pack or do you have to monitor the individual cells? Do they last two or more years before they get to 80% of their capacity? Dan.

RE: A123 Question
 

Dan I answered that in my last post. I had one go bad after 6 years. the other three are still going strong. Dennis

RE: A123 Question
 

Andy Griffith?...Extra Good! Best TV show there's ever been.

RE: A123 Question
 

I have been using A123 type batteries since 2008. I use the 1100mah in smaller 90 to 120 size and the 2300mah in my 500cc and above aircraft. I also use 3 1100mah cells in my Futaba radio. I cycle them every spring and none have come close to failing so far but I never let them get below 3v per cell either. I love the fact that it only takes 10 to 15 min to charge at the field and they never develop a memory. I have a spec sheet from A123 somewhere in my files that states they expect their batteries to last at least 10 years if properly maintained. I hope to get 10 years out of mine - over 4 so far.

RE: A123 Question
 

LOL thanks, it had nothing to do with the show, or at least my parents so claimed.

RE: A123 Question
 

I have 2 packs that are 3 years old. While I don't do a formal cycle on them, though my Hyperion 610 easily could, I charge them with a Cell Pro, I fly a lot, and I verify Mah and balance with each charge. If I were to fly a couple of flights and charge and an unusal amount got put back in, then I would know it was time to investigate.

RE: A123 Question
 

Dan,

Any decent charger that has a cycle / discharge function will work for the A123 / LiFe batteries as long as the discharge current and cut-off voltage can be set by the user. I prefer to use a manual mode, note the capacity then proceed with a normal charge after that. Note for measuring battery capacity you're only measuring voltage at a specific current / time so the device isn't battery chemistry dependent. Even an old NiCd / NiMh device would work well for this purpose as long as it meets the basic requirements.

So far after over 2.5 years of use my A123 batteries are not showing any loss of capacity. Very unlike Ni chemistry batteries that show some loss of capacity from the day they are put in use forward.

I'm an old guy compared to most here but no dang antique 8 track players for me! Also no voltage regulators ..... never used one, never needed one and never wanted one!

RE: A123 Question
 

Here in Ky. where I live between mid Dec. and March flying is very hit or miss because of winter. If i don't get to fly my big planes because of winter I have found when charging in the Spring I only put in 300ma. Those battery's sat for 3 months. Dennis

RE: A123 Question
 

You need to come down here, we have a week or two of winter where we have to wear light jackets to the field :D

RE: A123 Question
 

Lets be clear here, on a Lithium-ion battery measuring voltage at the field can tell you the state of charge in the battery but it will not tell you the capacity of the battery. You can only determine capacity by measuring how much voltage the battery can supply at a given current over a specific period of time. You stop measuring when the voltage drops to a pre determined value.

RE: A123 Question
 

You are correct, I should have said "monitoring their state of charge is a quick and simple procedure".

Just as with Nickel-Cadmium batteries, I stop measuring and stop flying when the voltage drops to a predetermined value.

RE: A123 Question
 

Love life batterys, can have a model lying about for six months untouched then decide to fly it that day, simply put it on fast charge, go pack the car, see the battery is fully charged after a couple of minutes and has only lost 20-30 mah in six months, go fly.

RE: A123 Question
 

Andy Griffith? I feel like you have been holding out on us with that one!

Got a friend in Naples that complains the summer is too hot to fly; airplanes melt on the runway LOL.

Tom...Tom Fiorentino; no famous connection with that name.

RE: A123 Question
 

Andy Lowe with Electro Dynamics has developed a field test meter for A123's it displays per cell voltage and his guidline is after a 10 second load if cell voltage is above 3.1 your good for another 500mah use flight. Have used this for almost 2 years now, it's easy. It does not replace knowng or noting the mah put in during a charge or knowing an average mah used per flight.

RE: A123 Question
 

Eh, it gets hot but we have a nice pavilion with ceiling fans, and when its that hot you get out early and fly till lunch time then go to the beach.

RE: A123 Question
 

So now the truth comes out. You fly half days....THAT is why you can get by with ONE 2,300 mah A123 on a 50cc bird. Just kidding!!!!!

Really...just kidding.
Tom

RE: A123 Question
 

LOL yea, that and the fact they charge in about 10 minutes.

No worries, as a mod I have a thick skin, I've found my experience as a kids hockey ref helped tremendously :D

RE: A123 Question
 

If you want an interesting read on A123's check out Hangtimes Hobbies. Steve has some great information.

http://www.hangtimes.com/index.html

RE: A123 Question
 

I run a pair of 2300mah A123's in my 30cc MX2 for the RX and servos. I run 6 Hitec 5645 Servos and I can put over an hour, 60 minutes of "ON" time on those packs and barely put 200Mah back in them, meaning 100Mah for each pack.

Doing the numbers, I should be able to fly for 23 hours before the batteries are dead! Maybe it's overkill for a 30cc plane, but it's nice to know that I can virtually leave the system on for hours on end at the field (adjusting throws, adding mixes, etc) and still fly enough to be bored without being in fear of reaching the battery capacity.

RE: A123 Question
 

Well, I would say it is more a function of the number and type of servos you are running and not so much the cc of the engine (although bigger cc's usually come with more servos). Anyway, I don't know if you have ignition on the 30cc, but either way, 200mah on 60 minutes of run time seems out of whack to me given 6 servos. That isn't even close to my experience...

Tom

RE: A123 Question
 

With my 50cc I burn about 300 to 350mah per flight with 5x 7955 and a throttle servo doing 3D, that's recievers and ignition. So thats what, 7 flights till dead? I fly 4 then charge, I usually put back 45 to 55 perecent of capacity.

RE: A123 Question
 

Hey 'Cuda I'm sorry but can't resist. That is my experience...exactly...except I'm dead at 14 flights and recharge after 8 :D:D

Seriously though...this is the same as me; maybe I am a little lighter because I am not a big 3D guy. Good to know.

Tom

RE: A123 Question
 

My 50cc planes use between 275 and 325 mah per flight, 30 cc about 225 to 250mah all using the same servos. Hitec 7985 on elev (2) and ail (2), 7955 on rudder and a smaller JR digital servo on throttles (don't remember model number). Seems consistent with your findings considering you are using 7955 all the way around.

RE: A123 Question
 

Well of yes, 30cc has nothing to do with it, unless of course you figure the flight loads on a 12lbs airplane versus a 35lb plane and what that does for battery consumption.

Nothing is out of whack, I assure you. I check my stuff every weekend. I fly smooth aerobatic type manuevers, no 3D yanking and banking. I invite you to come by my table anytime you are in SpringHill Florida and check them for yourself. On a quick morning where I only have time for 2 or 3 eight - ten minute flights, it is quite not out of whack to only put 50mah back in each pack.

2 2300 Mah A123's from TailDragger RC, 6 Hitec 5645s, 1 Smart Fly Bat Share, 1 Smart Fly Equalizer II on a Hitec Eclipse 7 Pro radio.
I run a 7.4v Li-Po for the ignition, which is independent of the A123 batts.

BTW, I sorta really love it when because "you" don't have the same experience, so many act as if what anyone else says is impossible. Come by my field, fly my plane, top off the batteries...
Whjy would I make it up and give false numbers? I check my stuff after every flight day.

RE: A123 Question
 

I can't resist either. My MX2 is sitting exactly as I left it from last weekend when after one 12 minute flight upon pre-flighting her I noticed a broken pinch bolt on 1 aluminum servo arm. So the batts have ONE 12 minute flight and they have sat since Sunday. I am going to charge them and photograph the didgital read out on the charger for you. Will that be sufficient?