The lowdown on A123's?

[Fade-Dude]

yes yes I know its probably been discussed in some way or another.....
But I need clear cut answers if someone can spare them...
Guys who have tried it, with results....

how many cells I need? stock 50Amp ESC, stock 850 motor....
Where do I get them.... I know in dewalt power packs, but where...?
How / with what do I charge them, can I charge from 12 Volt?

What are the flight times like?

I am quite finished with puffing lipo's and crappy power delivery.....

[istandalone]

you need a specific charger that is capable of charging a123's (called LiFe cells sometimes) the bantam bc6 is just one and it's fairly cheap. your best bet for dewalt packs is ebay, but if your like me i hate ebay after getting burned a few times. this is a good source for them besides ebay http://www.toolking.com/dewalt_dc9360.aspx but they are out of stock right now. as far as how many cells you should run, and run time you'll need to search, there have been a ton of threads on this subject. and it is possible to charge a123 cells straight from a power source but i have no idea how to do it. you'll get less power from a123's then you would normal lithium polymer. if you know how to take care of lipos you're power delivery should be good and the packs should last a long time if properly taken care of and not abused. what kinds of packs have you used to make you sick of lipo? if you bought cheap no name lipos then you'll get cheap no name performance. a good motor/esc with good lipos will deliver more power then nitro.

[Fade-Dude]

Thanks dude....

I use cheap ass lipo's, yes...... but even friends with "not so cheap ass lipo's" suffer from the same symptoms I do... I udnerstand that lipo is the here and now... but I am at a stage where I have two options it seems:

1) Buy all new lipo's and propper chrarger.... still sit with all the lipo cons....
2) Buy all new A123's and charger..... there seem to only be pro's... (well, alot more pros than cons)

The question beggs..... should I go A123 or Lipo....

My hurricane is stock..... I have enough power, but only for like 2 second bursts...
They drain quickly and I only get like 4 minutes of flight time.... the cells dischrge unevenly, almost always causing one or the other to "puff"

A123's.... can be abused, similar power to weight.... recharge in 15 minutes..... don't "puff" :) , more robust.....

Well this is what it seems like to me..... and thats why I need opinions / info...

[istandalone]

the answer to your problems lies here. http://www.readyheli.com/Kong_Power_3s1p_11_1v_2200mAh_25C_Lipo_Battery_C_p/kp-2225-3charger.htm
these packs are great, and you can gear your heli to be more efficient. with those 2200's you can get five minutes of decent flight. also, if you want bigger packs then 2200's, you could email readyheli and they might make you a package with 3300's or such. plus, those KP packs can be abused pretty hard before they even start to fail. but, i've never used a123's myself so i'm not the best source of info for them. the only reason i'm not using a123's is that i don't have a charger that will charge them, and really don't want to buy yet another expensive charger. also, if your handy with a soldering iron, you can buy loose lipos and make your own packs. check out www.maxamps.com (http://www.maxamps.com) you can get reasonably priced lipos and even loose lipos to make your own custom packs if you want. what kind of charger are you using now? i've got an mrc superbrain 977 which will only do up to 3 cells lipo, but two packs at once. for $100 it's a great charger. some people here don't like them, but i've never had any issues whatsoever. i also plan on getting the polycharge4 from tower, as this can do up to 4 cells lipo but will charge four packs at once. between the mrc and the polycharge i can charge 6 packs at the same time. now that will rid me of the "waiting for the charger to charge" blues. the polycharge doesn't display mah put back in the pack, but the eagletree data logger tells me how much mah i've used.

[kgfly]

On the stock motor/ESC you can run 7s A123 but you will need to go up at least one tooth on the pinion to hold headspeed similar to 6s lipo. Flight time will be slightly shorter than a good quality 6s 2200 lipo due to the lower voltage under load of the A123 cells. Those looking for more power tend to go with 8s, Z20-980 and an HV ESC.

There are many options for charging A123 packs but since one of their great advantages is that they tolerate 4C charging without risk or damage and still give hundreds of cycles, a BC6 (although a great charger) which is only 50W/5A so would not be up to the job on a 7s A123 pack. A BC8 is better but really for best performance you would probably be looking for a charger with at least 200W/10A output. Some good ones include e902, TP1010C, EOS610iNET or 610iDUO or 1210i, Cellpro10s or maybe the new Chargery 1010B. You can also use a CCCV bench supply like the Mastech: http://helifreak.com/showthread.php?t=40579

There really is no better way to get the cells than DeWalt packs on eBay unless you want to pay premium prices.

For all you need to know about A123 cells, making packs, how to charge them etc take a look at these pages:

http://www.rcgroups.com/forums/showthread.php?t=779676
http://www.rcgroups.com/forums/showpost.php?p=6769001&postcount=2

I really recommend you read those pages and the ones they link to carefully before deciding which way to go.

If you stick with lipos be sure to get a decent charger. Good entry-level candidates IMO include the Cellpro4s, Bantam BC6 and Maxpro X6.

[Fade-Dude]

ok, thanks guys...

I checked out the ready-heli deal.... and I must say that I am very tempted......

Are the kong powers really good batteries, or again just average....... will they dissappoint?

How about the charger it gets bundled with....

on that deal I can get 4 batts and 2 chrgers for the price of 1 8s a123 and charger....

P.S. My motor "drains" quite quickly when I do punch outs..... might my pitch be too much? I think its only at like 8 degrees......

Idle up is 100% throttle....

Whatever I decide on, I want my heli to fly propperly for a change....

My mini titan is a rocket ship with standard config and 2200 mah el cheapo batts...

where do I go from here getting that on the hurri....?

[bugdozer]

KongPowers hold up well to abuse but I'm going for the 3200 for more flight time and less chance of puffing. I've already puffed two of my older FlightPowers.

The DN charger is a good basic charger but check the output voltage with a accurate volt meter. Mine was over charging the batteries up to 4.28. If you pop it open, you will see four little pots with glue on them. They can be adjusted so the charger read out matches your volt meter while charging a battery **** DO NOT DO THIS IS YOU ARE NOT COMFORTABLE WITH ELECTRONICS **** If you adjust it the wrong way, your LiPo could burn up! I claim no responsibility for your actions. :shock:

[kgfly]

The DN charger is not all that good. Voltage precision has been questioned (as mentioned above) and it does not tell you enough about what is going on, especially as it does not tell you how many mAh went back into the battery. This is vital information for understanding how hard you are running your packs (you never want to be recharging more than 80% of the nominal capacity) and how they are aging.

The KP batteries have a good reputation and are more tolerant of over-discharge than most other brands due to their unique formulation, but they are still lipos. You have to learn how to setup and operate your heli properly so as not to abuse your lipos. A key factor is to know how much you are draining the packs so as to stay below the 80% threshold. You must also ensure the cells never exceed 55C (140F) as this will permanently damage them.

Your bogging problem is almost certainly related to your cheapo lipos not holding voltage under load. The KP packs will probably perform much better.

If you want to go the lipo route and want a budget charger then I strongly recommend the FMAdirect Cellpro4s. It is far better in every way than the DN charger AND cheaper. Normally $75 it is often on sale for $65. If you want to charge two packs at a time you can get two or get the Cellpro10s. instead. There are many other good charger candidates.

[Zoobie]

FAde, I am running the Z20 motor and 2200 Kongpowers from readyheli and I can push my heli fairly hard for 5 min. If you fly mildly I think you might get 6min. (14T pinion) and the climbout is great. If you want to run the stock gaui motors then I would definately rethink your battery situation.

[Vinger]

Guys/girls,

Get the Megapower Infinity 960SR, it can handle both A123 and Lipos, as well as your TX/Rx packs. Twin balancers allow you to charge up to 12 cells!:clapppJust make sure your powersupply is up to it.

Got mine from www.eletricheli.co.za (http://www.eletricheli.co.za) The best deals in SA:cheers

[vicrc]

With the stock Gaui motor, you will need a lipo in the 25-30c. I just got my Z20A 980 motor will test again on my 20c packs.

[kgfly]

...Megapower Infinity 960SR...
This is an interesting charger, also sold under the Robbe and Tamazo brand names. I have not had a chance to play with one in person but have only seen positive reports. It is 180W output so not quite as powerful as some others in the market. This charger/balancer combo is also available for a good price from HobbyCity: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6301

[Mikej]

The DN charger is a good basic charger but check the output voltage with a accurate volt meter. Mine was over charging the batteries up to 4.28. If you pop it open, you will see four little pots with glue on them. They can be adjusted so the charger read out matches your volt meter while charging a battery **** DO NOT DO THIS IS YOU ARE NOT COMFORTABLE WITH ELECTRONICS **** If you adjust it the wrong way, your LiPo could burn up! I claim no responsibility for your actions. :shock:

BD,

Thanks for this - just re-calibrated mine as it was over-charging them buy about 0.2 volts per cell - only needed tiny adjustments but much happier now.

Mike.

[istandalone]

my dn power charger reads the same as my superbrain 977 and the same as my bros tp1010 so i think i got lucky on that. i'm telling you if you want kong power packs, email ready and even though they don't advertise a deal on a pair of 3300's like they do for 2200's they'll cut you a deal i know it.

[bjosko]

This is an interesting charger, also sold under the Robbe and Tamazo brand names. I have not had a chance to play with one in person but have only seen positive reports. It is 180W output so not quite as powerful as some others in the market. This charger/balancer combo is also available for a good price from HobbyCity: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6301

Yes indeed.
I have this charger (and promised to report back in an old thread on the battery-forum, never did that ), and it is superb for the price asking. It takes 25 min for a full charge on my 7 S setup, but the last 5 minutes are about 1-200 mah balancing-time.

My 3S A123 (for fun setup) on my T-Rex 450 are fully charged after 17 minutes. (About 10 minutes normal flying).

Plus, it is perfect for lipos and Nixx to, I would never need another charger, unless I wont faster charging for my A123, but with 2 battery packs already, I really don't need anything more.

[istandalone]

i can't quite figure it out, that charger will do two packs at once?

[bjosko]

Yes, if you have 2 similar packs it will. There are 2 balancing boards with each 6 cells capacity. Put the packs in series on the main lead via an y-cable that you also have on your Hurri, plug in the balancer-sticks, set the voltage and current, and charge :-)

(I am only charging one A123 pack at once, but if you have 2 identical Lipos, that is the way to do it. I could however charge 2 3S A123 packs that way if I wanna to.)

[concept1]

I am flying both A123 and Lipo, and I am really still not sure which way to go? for cost the A123 has a real advantage, although maybe not recomended you can go a real cheap route with A123 with good results.
my setup is this, I am running the RCP h/18 1100kv 1000w motor, on 6s flight power evo 2500's performance is awesome, and I get 4.5 minutes of flight. it is a lite and powerfull setup. i decided to try the A123 route because all I had for a charger was a polycharge 4 which I used on my Trex, it does 4 packs at once but doesn't give any info on packs, nor does it balance. with this also said i have never had a pack go out of balance i do take care of them, althought I have lost several do to crashes.
with the A123 packs I decided to go the "cheap" route just to try them, I grabbed a variable bench top power supply from ebay for $25 it does up to 50v but only up to 6 amps. I first tried 7s A123 and it works well, not for a 3d guy but perfect for a begginer, to intermediate, very good power through the full flight, I also get 4.5 minutes on the A123's. head speed is lower then the 6s lipo. I now fly 8s A123 and it gives slightly higher head speed then the 6s lipo, but do to the extra weight overall performance it about the same. it takes about 20 minutes to charge at 6 amps, this summer I will most likely get a new power supply to do 10-20 amps. I have many many flights on a few of my packs and sp far no balance issues, I have no balance tabs but I can test each cell manually with probs and if i need to (which I haven't yet) I can charge each cell on it's own with my power supply. I am very very happy with this setup, and have no future plans on going with balance tabs or changing to a "normal charger" when I first got my A123's I did a lot of "testing" or playing with them, I overcharged them I let them totally discharge I threw them on to my driveway etc. I did manage to destroy 1 cell it was the one I really really overcharged and then threw onto my driveway. but for the most part overcharging and over discharging has had no effect as of yet,and 3 of my test cells are now put into one of my 8s flight packs. so for me I am sold on them. my guess is my packs will outlast my heli. I am not looking into going 10s to get some better efficiency, but i would also not discount some of the new 3300mah lipo's now that are becoming cheap,I also want to get 2 of them now, it's a tough call,

[Fade-Dude]

thanks for evryones replies!

concept1, where did you get these "cheap" a123 options... and tell me more about that bench top charger?

[concept1]

I have gotten them on ebay, for $100 shipped for 10 cells, so if you are after a few packs you can have them for about $70-75 per 7 or 8 cell packs, vrs my evo2500s which were $85 each so $170 per flight pack.
I am using a tenma labratory power supply, 0-50v and 0-6 amps, i found it used on ebay i think I paid $37 shipped, but figure $100-250, I got lucky, if you have the time you can find anything cheap. i would like to find a 10+ amp but for anything over 6 amps they become costly 200+. I didn't want to invest untill I played with the A123's first. i now have had them since sept 07. I also have a friend who works for B&D who was able to get me some packs Cheap!

[WuTangcl]

THIS MOVIE ON PUTFILE (http://media.putfile.com/Abusing-my-Hurricane-550-with-8S-A123s), That's me flying my Hurricane 550

I use stock 980 Kv motor, Stock 50A esc, 2100 HS and 2x 4S A123's
thus 8S1P A123's
I got 4,30 mins flight time, and then about 20 secs to land before headspeed drops
because the A123's are drained...

I charge them with THIS Powersupply (http://www.lipoly.de/index.php?main_page=product_info&cPath=880_926&products_id=6481&language=en) using the following setup:

Got 6 x 4S packs ---> 3 x 8S ---> 28,8 volts

For charging 8S3P
2300mAh x 3P = 6,9 A/h x 4,52C = 31,20 Amps charging, thats 28,8 volts on 31,20 Amps
60 mins : 4,52 C = 13,30 minutes of charging and all packs are ready to go

So flying 3 x 4,30 minuten including changing packs is about 25 minutes and then charging,
After a cigarette a cup of coffee and a good chat with my friends its back in the air after 15 mins.

But IRL that only good for 2 cycles, thats 6 flights in 1 hour, after that I really need to sit down
a bit, its real nice to almost keep flying continuously, but lack of concentration is also an issue
after so many flights...

So now ya got a good idea about the A123's, if you really want long flight times, dont go A123
if you think you can handle the changing packs and continuous flight throughout the day the do go A123.
But if you have enough after a couple of flights, then just buy LiPo's and like 2 or 4 chargers, then
you can get a few flights a day also only not contniously...

Like Concept I also like them A123's very much, its a little hard to get them fit right into the canopy,
but it does, I am not going back to LiPo, Not saying LiPos arent good, because my A-Plus 2200's 25C
still going strong after 70 flights, But I like the the idea that my A123's can go up to 1000 - 1500 cycles...
Like Concept says, the A123's probably outlast the heli, its a few bucks more on first purchase, but
it really pays off on the end.
Not having to worry when you crash you could destroy a pack, those LiFePo4's really can take a beating.

[kgfly]

WuTangcl - Very interesting. I would love to see photos of your packs and how you mount them on the H550.
* Are the 4s packs slab style (4 cells side-by-side) or shotgun (two sets of two cells end-to-end beside each other) ?

* What did you have to do to get the balance right with 8s A123 ?

* Do you have to make any changes if you want to fly 6s lipo instead of 8s A123 ?

[concept1]

I make no changes from 8s A123 to 6s lipo, 8s A123 I get higher head speed but with the extra weight performance is pretty close a good 6s lipo. my balance is also pretty close, just slightly nose heavy on 8s A123, when the weather gets better i do plan on spending some time with gearing and different battery configs to see if I can get osme better flight times, i feel on 8s A123 I should be able to get better then 5 minutes if I really set it up for A123. just hovering around 8 min would be fairly easy. but for now I have been running a flat 100% curve.

[Fade-Dude]

WuTangcl , concept....

How does the heli feel in the air with the extra a123 "weight"?

its almost a third heavier.....!?

I once tried a firends 3300 packs.... and it was quite alot heavier than the two 2200 packs.... and the heli felt "strange" in the air...... "fell" out of loops and just felt overall sluggish....

What are your experiences?

[Fade-Dude]

P.S. WuTangcl , do you just apply DC volts to it? and work out how long for it to be fully chrged? Do I not need a "special" a123 charger?