JoeAirPort

My Feedback: (41)

If it's the 88" Yak you're talking about...or a 50cc bird...it would be 225 total per flight. That's about what my Yak pulls in 12 minutes of flight (with 7955's. Extra a little less with 5955's). You could easily do 2 x 1100 A123 for the receiver. Or one 2300. I do one 2300 on my Extra and Yak. Perfect size battery for a 50cc. If you are already setup for two packs, then I'd go 1100's. Two 2300 is pretty heavy...about 12 ounces total depending on how much wire you have Rich attach to them.

weezle

I run 2 1100 a123's on my Rx, I use 150 mah per battery per flight. so 300 mah total. Its been working out real well for me. My only gripe is a minor one, the fromeco wolverine switch will not allow me to charge both batteries at once with both of them plugged into the switch, the charger gives me an error saying common ground. I just charge them seperate or remove the canopy unplug one of the bats from the switch, and charge both at 4 amps

diamondave

My Feedback: (29)

yeh its my 88edge i was asking about, i know you guys are smart over here....anyway, i was thinking about it too, its got to be 225 total, cause the wolverine draws from both together, not one then the other, so i used 225 from both, but it keeps them even as if it were one pack with 2 leads, so i got to rethink it, having say two 2000s on the plane does not give me 4000 available, only if it drew off one then the other, thats not the way it works, so to me that means two 1100s still only gives you 1100 capacity right? thats the way im thinking about it, so since i have the wolverine and im set up for two i thnk i will get two 2300s, i will still only have 2300 total then not 4600, at least in my mind it seems that way, and i have two 2000 methdrides in there now, the 123s are within an ounce of wieght with each one, so it wont add anything noticable, if im wrong and end up with tons of mahs available then i guess i know i can fly all weekend without charging...just going to decide about the balance thing now, joe your idea of just doing it once in a while sounds good, then i dont need to add another exteral port on the plane, as long as i can reach the balance lead i should be okay, i was asking rich about somehow making an "extension" for the balance tab, so i can reach it easier and move it to each as i go, i think with the canopy off i can rest the charger on the formers and maybe reach them all...

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Dave,

If you run two 1100's and your system has total volts of around 6.6v then your capacity is 2200. The A123 - 1100s typically have a usable capacity of 900 to 1000 max. So you are looking at 1800 to 2000 total capacity. It is only if you double the voltage and as the two batteries to give 13.2v (not recommended) that you would have the smaller capacity.

The 2300's give a healthy 2300 capacity. They are the most robust battery (like a 4600 is more robust than a 2300 liion) and can take a lot of abuse. The 1100's need to be balance charged in the beginning of their life cycle. (2300's too but to a lesser extent)

Think about this....when people first started using A123's they were dismantling a 36v dewalt battery pack where the factory assembled and balance charged and partially discharged (in theory at least) before going out the door. Each of the 10 cells in that pack all had the same voltage and were "Married" to each other. Guys put them in their planes and low and behold....they did not need to be balanced because each cell was used to getting the same voltage up and down the range.

Nowadays, batteries are purchased from the factory built and then used. When I build each pack I make I monitor cell voltage at the bottom of each made up pack and again at the top. I cycle them as many times as then need to get the cells working together....or married... In the first dozen cycles the individual cell voltages can drift if not balance charged....at the top of the range a half volt difference can mean several hundred mAh of out of balance...(translates to missing capacity)

More so the LifePo4 manufacturers(notice I did not say A123 Systems) are recommending balance charging for the first 20 cycles. The A123's are better but nothing is set in stone....but here is the clincher.....

Most balance chargers show individual cell voltage when you start to recharge and when you finish......These batteries will not last forever even though the 2300's are spec'd out for 1000 cycles or 10 years shelf life....(for the designed application in power tools that draw much more and charger back harder)....but at some point in the future there will be a decline....nobody is reporting on it yet to my knowledge ....but would it not be nice to know on a regular basis that your two cells are functioning normally? And at the point that it becomes un-normal wont it be nice to see if before the famous words are spoken..........

xtraflyr

My Feedback: (11)

So far I've been happy with my 7.4 2000mah lipos. After 30 minutes of flying,I only put 400mah back into each pack. As long as you use servos that can handle high voltage you don't need the reg.

I do have a warbird I was thinking about getting 123's for. I'm thinking one 2200 should be plenty for it since the servos aren't being worked so hard ?

Frank

JoeAirPort

My Feedback: (41)

Dave 2 x 2300 A123 is way over kill. Most guys use that setup on birds like a 110" Yak. But if you want to go with 2 x 2300 it certainly won't hurt anything except your wing loading.

Frank 1x2300 would be fine. I have that on my Extra and Yak and don't even use 1000 mah in 5 flights.

diamondave

My Feedback: (29)

i dont think it will change the weight of my plane at all, maybe literally a few ounzes, my 5cell hobico 2000mah packs are around 5ozs each, i weighed them myself, so rich says the 2300s are 5 something ozs, the only one that will be heavier is replacing my 4cell 2000pack currently on my ign with a 2300, and that cant be much either, i bet on most scales the wieght wont even show a difference on the plane....im leaning that way...dont worry rich you will get a sale from me soon, haha......i just sold another prop to someone, could have been you

JoeAirPort

My Feedback: (41)

Dave I see your reasoning. You're comparing your current setup weight of 2 x Nimh. I was saying that you could save weight with the 2 x 1100 A123. Probably 5-6 ounces. May not matter to you. Also 2300 is way too much for ignition. If you swap out all your Nimh with 2300 A123, you're right....the weight won't change much. You could probably drop a half pound with all 1100's.

diamondave

My Feedback: (29)

well you saw my post on the dle thread, im using 225 on my ignition per flight, 11-12 minutes, so an 1100mha pack usable will not get me more than 3-4 flights before id need to charge, that not enough, i dont always bring my charger to the field, i guess i could make it a habbit and do so, but i like the idea if i top off at home in the morning before leaving i can have a day of flying without needing to charge...so unless something is wrong with my ignition and im using more than im supposed to be i got to go with a 2300, and yeh for the rec. packs it wont make any difference in wieght, so might as well go for the bigger ones that keep me juiced all day safely...i got an email in to fromeco to see what they say about the whole double battery thing, hopefully they let me know by monday or tuesday, i used to think i had double the mha capacity with 2 batteries but im not so sure now, which is fine, the entire reason i run two is for safety, not to instantly double flying time, sure if in fact with two bateries you double mhas and can shave weight off i may do that, i just want to make sure im thinking of it correctly before i blow a wad on batteries

diamondave

My Feedback: (29)

plus, i forgot to say im kinda thinking ahead a bit, if ef announces a 80cc or 100cc edge at some point i most likely would sell my 88 edge to try and get the bigger one, like i did with my 88yak, then i transport the 2300s into that one, darn ef always making me want new and more expensive planes

JoeAirPort

My Feedback: (41)

Yeah I agree. The 2300 are much more transportable to bigger planes than the 1100. You can't be using 225 mah on a single cyl ignition. More like 100 mah per 10-12 minute flight. I kept track of mine for a while and it was 109, 111, 115 mah per 10-12 minute flight. I think you would get 225 with a DLE-111 ignition.

diamondave

My Feedback: (29)

well thats what i was putting back in, i made notes, was 225, then 229, then 227, so its consistant, and its a fairly new battery, maybe a few months old tops, maybe its my menz prop or my lightning fast thumb....

diamondave

My Feedback: (29)

i was just looking around to see what i could find out, tbm says to use a 1400 on the 55 and you should get 6 flights or so, i assume that means a little to spare since you cant take them down completly, so lets say leaving 200 to spare, that would be 200 per flight giving 1200 used, either way seems like they say 1100 is not enough, valley view doesnt specifially say i dont think

Slow and Steady

I was intending to use 2 Life 7.4 2100 mah batteries in my yak until I weighed them. Each is 4.5 ounces. However, I will be using a battery eliminator, which will save the weight of the ignition battery. Any thoughts or experience regarding the reliability of the battery eliminator? Haven't noticed anyone on this blog using one.

House2twist

I don't like those battery eliminators. If you ever end up having engine problems, it could cause a huge headache. I'd just go the route of each of the 2100 packs into a switch into the receiver and then have a seperate ignition pack and switch. I wouldn't leave something as vital as an engine ignition to a module like that.

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Dave, here are some ignition usage on a test stand for Rcexl I believe...gonna be real close to other brands.


Post 24

http://www.flyinggiants.com/forums/s...=2#post1252759

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Forgot, you have to insert flying giants where the asterisk's are.

Edit. Here is copy and paste of Milton T. post in that thread on the other website that I cant talk about here......

This is some battery drain test that CH ignitions did.

Copy and paste

I just have done some battery drain tests.
All tests were done at 8000 RPM.A new single cylinder, Version 2 CHXL Ignition.
7.2 Volts -725 MA
7 Volts -675 MA
6 Volts -650 MA
4.8 Volts -475 MA
3.7 Volts -375 MA
3 Volts 300 MA
2.5 Volts 250 -MA

Richard D Bahmann aka/Wrongway

My Feedback: (42)

Funny, no www but it wont let me say it....

Lets try it backwards Giants Flying...

JWilliams

My Feedback: (6)

Getting the yak dialed in for the King 50. The OS55 is really running good, idles about 1700 and top end at 7400 with a 22 X 8, going to a 23 X 8 tomorrow will post results.
Jeff Williams

cjcyclesrc

My Feedback: (10)

Cool. One of my friends brought out an OS 55 this weekend at the Austin big bird. It's seems to be a great running engine. I wish I could get loose from work to go to the King 50. I've got my 88" Edge dialed in and ready.

cjcyclesrc

My Feedback: (10)

Dave,

There is no question about adding together capacity's when you hook up redundant packs. If you hook up 2 packs, The MAH's of the two batteries are added together. Like Richard noted the mah's stay the same if you are hooking the batteries up in series.

How are you checking Mah usage? Nimh's and A123's are two totally different animals. You can't measure mah usage the same with the two batteries. You charge up Nimh's today and leave them sitting for one day and tomorrow the charger will pack another 100-150 mah's in. Nimh's are inefficient when charging also. To top off fully they need to be charged until warm. Heat means wasted energy.

Compare Nimh's to pouring soda into a glass. The soda foams up and if you stop when the foam gets to the top the glass is not totally full. You have to let it sit until the foam settles and then keep toping it back off until the glass is full. The other way to get the glass full is keep pouring and letting the foam run over the top of the glass until the liquid reaches the top. When you compare them think of foam as Voltage and the liquid as Capacity. The run over foam or run over charge is turned to heat. Also with Nimh's it's like the glass has a leak. So if you drink out 100 mah's of soda and let the glass sit overnight leaking, You may have to pour 200 mah's of soda back into the glass to get the liquid to the top.

Compare A123's to pouring Water into a glass. You pour in the water until the glass is full and you're done. A123 don't self discharge like nimh's so it like having a leak free glass. So if you drink 100 mah's of water out and let it sit over night not leaking, You would only have to add 100 mah's to fill it back up.

I really like the setup of one 2300 mah on the RX and one 1100 mah on the Ignition. You do have to charge after 4 flights though. I don't mind because the A123's charge so easily. I now have every plane I own set up with A123's. I even have my fuel jug and Transmitter on LiFe's. I would hate to know I had to use anything else.

diamondave

My Feedback: (29)

good anology charles, i toped off the nickls in the morning with my elite charger, that was after a slow 100mha charge on the multicharger which is not computerized or a "smart" charger, i set it(elite) a 1A to do the charge at the field, flew, then recharged at 1A again, did that 2-3 times, each time was almost identical at 225mha going back in each pack, whats wierd is that was all 3 packs, one on the ignition and both on the reciever, that means according to those numbers anyway i used 225 on the ignition and 450 on the reciever in a 12 minute flight, both seem very high, i have no buzzing or binding at all on the ground with engine off, in fact i got to hit the sticks when i 1st turn it on to make sure there is power, and at full deflection on high rate i dont hear anything either, so using 450 doenst sound right, i think my 110 with more servos uses less, i have found if i charge at a slower rate they will go higher, guess thats the false peak some guys mention, but i did it at 1A so it wouldnt take me all day to do my testing, if i went down to .75 or something it may have givin different results...i think i may just leave my edge alone for now, i am going to place an order with rich for my 110 yak though, 2300s all around with that one, ignition and 2 reciever packs. just deciding on balance tabs, my trunigy needs 2 leads i guess, 1 for charging and 1 for balancing, i hear the cell pro only needs 1 and you can clip the white wire and do charging/balancing together, so nothing else needed to add to the plane, can charge through my existing switch, but thats another 75 bucks for the charger, when i could just have the canopy off while charging and reach the packs with the balance lead, and i usually do take the canopy off while charging so i can see smoke 1st if something happens[X(]....so im leaning that way and using my current charger, at least to start with

House2twist

+1 for the A123's. So easy to plug them into my cellpro4s and @ 4A done within 10 minutes. I also run redundant packs on the r/x just for safety. I never did it on my smaller aircraft but I just would hate to see 3 grand flying helplessly into the dirt because a switch failed or something stupid.

cjcyclesrc

My Feedback: (10)

Dave,

Here is the best way to figure out MAH usage with Nimh's.

- Discharge the battery down. I always discharged them to 1 volt per cell. So 5V for a 6V 5 cell pack.
- Charge the pack back up
- Leave the pack sitting for a few hours
- Discharge the battery down to 5V again (I would do 1 amp)
- Charge the pack back up exactly like you did the first time. Same charger, Same rate, Same charge lead.
- Fly a few flights and count how many you flew.
- Discharge the battery down to 5V again. Same charger, Same rate, Same charge lead.

The time between the Charge and Discharge needs to be about the same.

Now lets make up some numbers for an Example. Lets say we are testing a 2000 mah 6V nimh pack.

-Discharge at 1 amp to 5V - not worried about mah's at this point.
-Charge at 1 amp and leave the battery sitting for 8 hours.
-Discharge at 1 amp to 5V - 1600 mah's drained
-Charge at 1 amp go to the field fly 4 flights and come home 8 hours later.
-Discharge at 1 amp to 5V - 1000 mah's drained

So 1600 - 1000 = 600 mah's used 600 / 4 (because you flew 4 flights) = 150 mah's per flight average.

Slow and Steady

I use Life and measure use by fully charging at field before 1st flight. Keep track of minutes on each flight and recharge when 4 flights completed. Divide Mah added by total minutes or total flights, provides mah used per average flight.