RC-Monster Forums - Flat A123 Cells- When?

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Flat A123 Cells- When?

I read somewhere A123 will be developing some flat 123 cells for ease of use. I'm looking for info or the date as to when these will be released. Does anyone know? JW because it sure would be nice to have the reliability of A123 with the compact-ness of lipo. What is the discharge rate and what will be the available MAH ratings? Does anyone have an idea?

Nope. I would like some though in the future- best people to ask are A123 themselves I reckon, or keep an eye on their website for news.

New lipo chemistry has come a long way.. 5c charge rates.. puff proof packs etc.. Not to metion lipo is about 1.5x to 2x as energy dense as well. Not much left to like about a123 if you ask me.

Puff proof? Where? Do you mean LiMn?

Kongpower have the puff proof and 3c charge & the New Neu's are 5c charge.. but are not advertised as being puff proof.

Quote:

KongPower batteries withstand over-discharging without inflation or damage which is unachievable by any other brand battery. This new and advanced chemical energy technology feature prevents users from damaging their packs carelessly. As an added safety unique to this brand, an internal PCB board has a built in fuse system to prevent shorts and thermal runaway should the anode and cathode become touched together during soldering or handling. This will render the pack unusable, to protect the user from fires due to sustained voltage shortage between the main leads. Customers who inadvertently short the main leads out will be offered a 50% replacement option should they elect to.

These packs come with the same 90 day warranty as the competing packs on the market.

SPECS:11.1V/ 2200mAh/ 25C (3S1P)
Size:110(L)x34(W)x28(H)mm
Weight:195g
25C(55A)Continuous 30C(66A)Sustain 50C(110A)Max Bursts
Stands overdischarging without inflation or damage.
Best performace if voltage is above 6.6V (2.2V/Cell).
Using a Timer is recommended to extend the life of the battery.
Balance Plug: TP style.

Important messages for rc boat and car users!

Model boat and model car are not aircraft which could have immediate danger upon the battery running low. Many model boat players are too excessive on their models to stop until their machines can barely move. This can deeply over-discharge the battery and consequently damage it permanently.

We strongly recommend rc boat and car users to use timers and BECs to prevent their expensive li-po packs from being damaged carelessly. Deeply over-discharging these packs could cause cell(s) to reach 0.0V or even negative voltage. This could short circuit it and cause it to puff.

Suggestion: Install the BEC for li-po batteries and set the cutoff voltage per cell to be 3.0V or above.

IMPORTANT SAFETY INSTRUCTIONS AND WARNINGS
You must read this safety instructions and warnings before using your batteries.
The three months warranty from KongPower Technology automatically becomes invalid, if one violates any of the following:
1. Use Li-Po balance charger or parallel charger only.
2. Maximum charge is 3C but charge with more than 1C could get false message from charger and is not encouraged.
3. Do not overcharge or direct charge, which could shorten the life of the battery and the battery could crack if severely over charged. Cell voltage must not exceed 4.2V per cell.
4. Do not severely over discharge the battery, or it could be damaged. The discharge limit is 2.5V per cell.
5. The cell voltage is best kept above 3.0V. The multifunction chargers might identify the battery as undetectable if the voltage is exceedingly low. Over discharge causes the cells unbalanced or any cell to be over charged. Therefore, over discharge is not encouraged.
6. Constantly over discharge the battery could cause voltage unbalanced as a result of power loss. If a power loss occurs, please charge the battery to 3.8V or above then balance-charge-discharge the battery for 1 to 3 times.
7. Continue to charge a battery that has begun to swell up will cause fire.
8. Never charge your batteries in car under extreme temperature, which could cause fire.
9. Never charge the battery unattended.
10. Do not charge batteries in series. This could cause overcharge, fire, or incorrect battery recognition.
11. Do not expose batteries in direct sun or place it close to any heat source.
12. Check the cell voltage regularly and balance the cells if they are unbalanced.
13. The battery could be hot after use, please leave it for 30 minutes before charge.
14. Please take caution of the above and take a good care of your battery to maintain its high performance and to extend its life.
15. RC model boat and RC model car players please take caution of all the above and also use timer.
16. Warranty:
The warranty does not cover misuse, unpacked battery, abuse, or other inappropriate use of the battery.
Product warranty is limited to original defective.

Does kokam make any bigger puff-proof packs? Like 5s?

WHY does the battery description say it CAN puff?

At the bottom of the description, it gives warning for car/boat users to be careful not to over discharge the cells or they will puff and be damaged...

Quote:

Originally Posted by marzac2 (Post 231819)

They are talking about massive over discharging... below allowed voltage not normal use, don't go to 0.0v and cause a short and you should be fine :) LOL

Quote:

Deeply over-discharging these packs could cause cell(s) to reach 0.0V or even negative voltage. This could short circuit it and cause it to puff.

How the hell can you get a cell to reach - voltage????

Quote:

Originally Posted by BL_RV0 (Post 231711)

I read somewhere A123 will be developing some flat 123 cells for ease of use. I'm looking for info or the date as to when these will be released.

Do you mean these:

http://visionarycomputer.net/rc/a123.jpg

Alright dave....spill the beans.....

ok im behind the times here. charge at 5C? 3C? so a 5s 3700 pack u charge at 25 amps?? so a charge takes how long then? not 5 times as fast

No, you just cant count :lol:

3700mah = 3.7amps x 5 = 18.5amps = a 5C charge rate will be 18.5amps = yes, 5 times faster than a normal 1c charge rate = about 12minutes instead of 1 hour = needs a charger that can do 342 watts.

Not sure there is any beans to spill, they are out. RCLipos has them in stock:

http://www.rclipos.com/AR18650-2S2P.htm

I've got these two with this slick little charger called the Nanophosphate Mini.

I just got them a few days ago and I'll be testing them out this weekend. I'll post up more news once I've run them. About the only initial comments I'd make are that I can't believe how light they are (185g) and that you can charge them in 20 mins (albeit at 8amps...) we shall see...

Sorry until they can pack 4400/4600 into the same space they are just worthless to me. Think about it, you need to have nearly 2x as much weight in your truck for the same run time as a lipo.. that is just unreasonable... the only thing a 1p a123 pack is good for would be a 5minute heat with a short warm up :P You couldn't even finish a short 'club' main with a 1p pack unless you were running ungodly voltage (12s or 13s).

not true I finished the last 6mins of the rcm bash with 6s1p after one pack fell off my G3R (at lutachs feet)

Yeah that's not quite accurate. I ran last years bash on 10s1p and only used up 1600mah. The power was still too much with the 2Y so I later detuned it to 9s, and think I could have gone down from there. Besides its not just weight you are looking at with the A123s, its many other adv and tradeoffs as well. Granted with the newest 30C/5C charge lipos they don't quite have the edge they did, but they are still really good cells for certain apps, and are excellent bashing packs due to their abuse tolerance and durability.

umm, they dont get dented? thats one thing im still waiting on for lipos. the ability to get dented and be fine.. not talking about extra cases here, the outside layer would be the -ve ideally...?

That's a pipe dream I think. Denting ANY type of battery is not good. Usually, cells are made up of conductive plates with the cell make-up in between. Dent it enough and the plates touch, which shorts out the cell. I assume you mean being able to dent them badly and not puff/flame? :wink:

What are the dimensions of a 2300mah a123 cell?

Quote:

Originally Posted by tc3_racer_001 (Post 232125)

umm, they dont get dented? thats one thing im still waiting on for lipos. the ability to get dented and be fine.. not talking about extra cases here, the outside layer would be the -ve ideally...?

They have had hard cased lipo's out for over a year.. just a FYI on that.. LOL thats not an extra case you need to wrap the cells together when in series.. doesn't matter the type a123 or lipo, you wrap in shrink or in a hard case. You want protection buy hard case, if you are smart enough to have a decent battery tray with good hold downs... it doesnt really matter which you go with.

25.85mm dia x 65.15 tall. Wt is 70 grams. Don

Holly crap. I am definitely going to buy some of these for my E-Revo. No cuttoff and no swelled packs sounds awesome to me. Don't get me wrong I will still keep my Lipos, but sometimes it feels like if I even look at my Lipo packs wrong they swell up on me.

even still hard cased lipos aint exactly ideal... IMHO. id prefer a soft case over a hard cased any day. why, the same reason i have a lipo sack not being used. id rather see that the pack is swelling when somethings wrong and stop it quickly than have it flame up on me... with a hard case it is the same idea. i have no idea if the cells are puffing or not. i just hope they arent!!!
anyway.... a123 seem more durable thats for sure.

Quote:

Originally Posted by hyperasus (Post 232340)

Keep in mind they are 13.2v vs 14.8v so top speed will be a touch lower (no loss in torque though) and you will get less than 12minutes run time on any brushless setup (unless you drive like a grandma of course). 2300mAH doesn't last long... for me I have a Truggy that is pulling near 300mAH per minute racing so those packs would last me 7.6-8 minutes max.. just enough for a qualifier, but I have to loose top speed to run them - not ideal. My erevo pulls a little less mAH per minute so my particular setup would yeild a run time closer to 10minutes.

I agree that at the moment A123 cells are hopeless for racing because of their weight to capacity ratio. But I have no races in my area so my toys are 100% built for bashing.

The A123 4600mAh 2S2P, and the 2300mAh 4s1p are 135mm x 55mm x 28mm

The E-Revo battery compartment is said to be 156mm X 50mm X 29mm

So only 5mm too wide gives me hope. There has to be a way. Then I could run as 2300mAh 4 cell, which would give my truck plenty of nards. Not sure what the run times would be but if I could squeeze 15 to 20 minutes of good bashing it would be good enough for me. I don't think I've ever drove my E-Revo for longer then 20 minutes in a single run so I'm willing to bet I wouldn't miss all those extra mAh.

The 4600 2S2P's are going to be about 1/2" too wide for the compartments on an E-Revo. I did a physical check on that with my batteries.

On my converted Revo, running an HV-4.5, I would get 20-25 minutes bashing time out of a pair of those batteries. And twenty minutes later, they were fully charged and ready to go.

Any aftermarket chassis for the E-Revo that will use all the stock trannys and drive shaft? This battery tray limitation is getting old already.

G-Maxx chassis with a 3906 Emaxx tranny.

Quote:

Originally Posted by hyperasus (Post 232497)

Any aftermarket chassis for the E-Revo that will use all the stock trannys and drive shaft? This battery tray limitation is getting old already.

what about the kershaw designs one?

http://home.ptd.net/~kershawd/Kersha...vo-Chassis.htm

Quote:

Originally Posted by hyperasus (Post 232407)

For racing longer than 15 minutes at a time lipo is probably the only way to go. For playing around and practicing a123 charge rates can't be beat for max time on the track without having a supply of lipos batteries and two chargers to keep you going.

I go to the local tracks with only 2 3s a123 packs. One charged 3s a123 pack, and one run down form the last outing. I plug the run down battery in to a 9 amp 12v computer power supply and it charges up in 15 minutes. Thats how long a charge lasts in my rustler anyhow. Swap the batteries and repeat. Just a couple minutes of down time while swapping the batteries before I am running the car again.

I picked up an 18 amp 12v power supply today so my charging time can now be less 8 minutes per 3s pack. 18 amps is above the 4c standard charge rate for a123 but others have been doing this for 100s of cycles with no significant decline in capacity/performance. You could charge two 3s packs at a time in parallel in just over 16 minutes.

Keep in mind if you use 3s packs you can use a computer power supply and a voltage cutoff device ($15 diy kit or $40 completed unit) and have a nice way to charge 3s packs quickly. With 4s you will need to get a high amp charger but then I think 10 amps is about the limit still and price goes up considerably too.

What charger did you buy?

I meant to write power supply, so I changed it above. Its just an atx computer power supply...

Quote:

Originally Posted by hoovhartid (Post 232526)

what about the kershaw designs one?

http://home.ptd.net/~kershawd/Kersha...vo-Chassis.htm

Two thumbs up. Exactly what I was looking for. I am going to get 2 of these coming for my E-Revo and G3R.