RC India

Hi,
I am looking for A123 battery packs and charger. Any store that could get this ?
I think its future for all RC battery requirements.
http://www.a123systems.com/

Let me know if someone can get this in India.
-Gaurav

Getting this to India is not a major issue as some  of the battery manufacturers who make LIPO also make A 123.
RC in general and electric RC in particular have just started growing now in India now .
LIPO itself is very new and as per majority  expensive.
Hence A 123 in my opinion is premature for India .
Even in the case of the western world it is still considered an expensive alternative to LIPO's .

If you let me know your specific requirement I could try to get it for you  as from a sellers point of view it is still a while before we can start stocking A 123 .
sai 

Are there really multiple manufacturers for A123 cells ? I thought there was only one. I haven't been following the aftermath of the enerland take over. There are a few other source of LiFe cells, but they don't match upto the specs of A123. A123 cells are pretty much indestructible and safer than LiPos, but most important according to me is the durability. There are too many dubious LiPos in the market which last as little as 20 cycles. If it is guaranteed that you can divide the cost with over 1000 flights as with A123, the cost looks reasonable.

Mean while some LiPo manufacturers have also upped their game by improving reliability like the kong power you have. LiPos still rule where weight is critical.

Yes, weight is the big constraint currently with A123.

Thank you Sai, Rotorzone for replying.

A123 is patented technology , and these batteries can be manufactured ONLY by the A123 company.

Now there are different brands who do the assembling, and create battery packs. The best ones i have seen are :

http://www.wildharerc.com/html/prices.html
http://duralitebatteries.com/flight/batteries-a123.php
http://www.fromeco.org/Categories/Iron_Corps_Extreme_LiFePO4/

Now the pricing is around $40 for a 1100mah Pack 6.6 V. Now this is not really too much considering the numerous advantageous these batteries provide over NiCD , LiPo and others.

-Gaurav

PS: Thanks anwar for this forum , at least we could have this discussion in the open without fearing it to be deleted / moderated.

Sorry for my ignorance guys .
I meant Li fe batteries being made by some .
As for the Lipo's I am  big fan of them.
I have been using various sizes of LIPOs from 11.1400 mah till 11.1 4300 mah around 20 -25 nos in all for the past 2 years the main brands being Zippy and Dong Yang and have had no problems with them what so ever. All batteries work great .
I have had just 1 failure with 1 no. 400 mah quitting .
As  a seller I have sold over 300 Dong Yang lipos and have had to replace just 4 nos till date which were subsequently replaced to me by the manufacturers .
Hence failure rate for these batteries has been around 1 %.

Sai

A123 technology is going to be the future, provided hobby manufacturers take it up and try to manufacture them in higher capacities.. currently you get the 2200 mAh version and a lower  capacity version.  For good deals on A123, check out http://www.aircraft-world.com

As already mentioned, weight is a big constraint.  In order to form a pack equivalent to a 4 cell 4400 mAh Lipo, you have to use 10 A123 cells.  2 packs of 5 cells in series connected in parallel.  Sorry if i sound confusing.  didnt know a better way of putting it!! That would amount to 10 cells.

In my opinion, A123s might be good substitutes for planes greater than .60 size.

But even i want to try it out on a .40 size plane.

Let me know if anyone has any experience with 123s!!

Chan

I think Li-Pos are far better than A123 as far as RC is concerned

Rao,
Could you give us some advantages of Lipo over A123 please ?
It would be useful information for everyone to know here.
-Gaurav

To me the weight to Capacity ratio is most important because I fly only Electric powered planes. What I mean by RC is Concerned I mean my kind of RC. Not THE RC. My knowledge of technology involved with Li-Po and A123 is next to nothing. I like Li-Pos because they are available in various capacities and sizes,they weigh less than the other types and they deliver high currents with ease. If you want to learn more there are a lot more experienced flyers outthere who would be more than glad to help you.
regards
Rao

Yep, except for the inherent safety issues due to their volatile nature (especially if you do not respect them), LIPOs are still the king when it comes to RC battery choices.

One thing I always hear when it comes to LIPOS is their volatile nature , I would like to ask just two questions about safety and fire :

1) Is Menthanol not inflamable , Volatile ?
2) Is Nitro Methane  not an Explosive ?

Guys if these two were not explosives you would not have had combustion in the engine in the first place .

The other factor that is missed is like any other new product the initial stages had all those fire hazards but all LIPO manufacturers have vastly improved the safety of LIPOS and those like KONG Power have made it extremely safe

LIPO technology has progessed a lot  lets move with change.

Value for money wise and weight wise  A123 just does not add up.
sai

I don't think it is that simple a comparison.  Let me share a few of my own experiences.

1) I have had a foam plane along with a small lipo catch fire (and the lipo explode) on me.  This was when I was just starting, and had a got new charger (MRC Brain 977), which defaulted to a charge current of 3A, which was too much for the 800mah battery.  Yes, my ignorance, yet what are the chances of something similar happening with methanol/nitro ?

2) I have had two lipos catch fire on me in heli crashes.  Again, when was the last time you had methanol/nitro catch fire on you during a model crash ?

Unless you put a smoldering cigarette into fuel, chances of it getting fire are pretty low, while a lipo can catch fire due to shorting during transport or charging, due to compression in crashes, and so on.   So this kind of a direct comparison is not a very practical thing. 

Having said that, recent developments (like the ability to detect shorts etc), and most importantly, the safe and respecful usage (especially care in charging and transport), have rendered them one of the safest and simplest methods of powering models. 

One good way to compare them is like air travel versus surface travel.  If taken care, air travel is one of the safest ways of transportation, with lots of benefits over surface transportation.  The key is maintenance/care of the aircrafts, and skill of the pilots.  If these are neglected, then surface transport wins, as your chances of walking away from a surface transport crash are pretty high !

In short, one just needs to be a lot more careful when dealing with lipos.  For some people, it is just natural, they don't even think about, but just follow safety guidelines.  For others, it is a determined effort.

LIPO Safety  has been improving by both manufacturers and users , hence they have progressed to a point where their usage has also become safer .

eg . We have LIPO charging sacks which are gire retardent  for those who want additional safety

Your last line says it all  people have got used to Glow fuel over and extended period and know how to handle it Comparitively LIPOS are new and people have started getting used to them hence compared to earlier days wrong handling has reduced  and will continue in that direction further .

Sai

guys

how heavy is life cell compared to an equivalent lipo cell of similar capacity ?

and how heavy is it when compared to output power to weight ratio ?

can anyone comment on this !