What about A123 batteries?

[Turbojoe]

I have to admit I've done very little investigation. If you read some non-RC articles you're lead to believe these batteries are going to save the world. Some RC'ers swear by them too. Are they cost effective and truly have the performance we need for heli's? If so then I'll buy a couple of Dewalt packs and tear 'em open. I like the fast charge rate they offer and the longer life span. I know some are using them. How about sharing your experiences.


Joe

[dutch_anykey]

Hi,

I know Piranha is flying his hurricane with 7s A123. He going to try 8s i think.

I just ordered a 7s pack as well. (7s A123 has the same voltage as 6s lipo) They are on their way. I had to invest in a new charger and balancers, so i decided to get one with A123 support.
From all the things i read...the A123 cells are a bit havier then lipo's, the capacity is still 2300 mAh max per cell.
My motivation to try one...I'm not a hot 3d flyer. I just started experimenting some moves. So flight time is a bit limited on the A123 packs due to their capacity. But then again i can charge them in a very short time, so i'm back in the air soon enough again. This keeps it nice even when i'm flying with one pack at the local club here.

At least that's the plan :D

Maurice

[ukpaul]

I've looked into using 7S A123 packs in the H550, but have decided for now to stick with lipo's. A 10 cell Dewalt pack on ebay is about £100 inc delivery over here, so that's £10 or $20 per cell, £70 or $140 per pack. The only model shop price here I've seen so far for cells is £13 or $26 each, somewhat pricey compared to the US price. Three packs would be needed really for back to back flights, so that's £210 or $420. I don't want to have just the one and wait 20 mins between each flight. I'd need a new charger for them also, & some way of balancing them. Chargers that can do 7S at big amps, like 8 or 10 are not cheap. Lesser chargers can do them but at lowish charge rates, which defeats the point of using A123 in the first place a little for me. For what I'd have to spend, I can get a lot of 3S lipo's which I can use in other models too.

As I get better & upgrade my motor etc, A123's might be a better option, as they cope well with the high current draws & you won't really have to worry about over working them in the heli, like you do with a lipo. A 70A constant discharge rate should cover even the hot setups.

I'm surprised none of the heli's in the hot vids were are being shown are using A123's yet, as they say even the bigger lipo packs they are using are having a hard time due to the amp draws.

I'd like to try a pack & no doubt will end up with one/some in the future when the cells &/or chargers come down in price a little, but for now will stick with lipo's I've already got.

[bclong21]

So what is the most reasonably priced charger for these cells? I can get a killer deal on those dewalt packs but I am like the others here- how do you properly balance them and how many can be loaded on the hurricane? I was thinking about a 8s set up- 2cells end to end and side by side like a ni cad stick pack. From my measurements it would work great- anyone got any thoughts? I am assuming you would balance these cells the same as lipo's?

[Wazzer]

Here is another supplier of A123 cells

http://www.modelelectronicscorp.com/products/batterypacks/a123.php

They also sell an interesting pack assembly system which is very neat.
http://www.modelelectronicscorp.com/products/SPTs/packs.php

Take a Look to see what you think

[trillian]

Here is another supplier of A123 cells

http://www.modelelectronicscorp.com/products/batterypacks/a123.php

They also sell an interesting pack assembly system which is very neat.
http://www.modelelectronicscorp.com/products/SPTs/packs.php

Take a Look to see what you think

Interesting.

I like the look of this battery for cost factor; ($51.99)
Magnum - 3-Cell 2200 mAh (3S1P)
Max Voltage: 12.6V
Weight: 171 g (6.10 oz)
C Rate: 20C
Dimensions: 24mm Thick x 37mm Wide x 100mm Long

[dutch_anykey]

Hi,

I ordered a charger and a A123 7S pack. It all has to arrive this week i hope.
I needed a new charger anyway. I had one charger that could only go up to 4s Lipo. It all went allright flying my hdx450. But since i got the hurricane 550 i had to charge four 3s packs after another, so the waiting time get's annoying.

I found a good price on the EOS 1210i charger including 2 balancers. This set also supports A123 (charger AND balancers). For me this is the ideal charger.
I can charge two 3s lipo's at once when connecting one lipo to each balancer. And when putting the balancers in Master/Slave mode i can go up to 12s max. (noted that i can not charge at full 2c charge rate due power limitation of the charger).

Since this combo also support A123 i decided to go for a 7s A123 pack to try on my hurricane. I'm hoping to get a small performance increase from the 7s A123 pack (coming from a "no brand" 3s lipo combo)

http://aircraft-world.com/shopexd.asp?id=4901
I went for the 225 us$ combo including 2 balancers and network cable

Here i got the 7s A123 pack
http://www.infinity-hobby.com/main/product_info.php?products_id=1795
This pack is specially made to fit the hurricane.

I hope i can test this combo in the upcoming week.

Maurice

[Cryofix]

I would think about a 10S setup with this heli "when" I get one, I am just not sure if its gonna be 10s1p or 5s2p

5x3.3= 16.5 volts/4600 mAh which would be for mild long flight times
or
10x3.3= 33.3 volts/2300 mAh for insane performance

More than likely I will use a CC45HV and not sure on motor yet.


here is my Trex 600 on 14S http://www.rightfullywicked.com/vid/T600%20on%20A123%20cells.wmv

[quickster47]

I picked up a couple of the 7S A123 packs from Infinity-Hobby when they first released them and while they do work, because of the way they are assembled the OEM canopy basically does not fit.

I have one of them disassembled and will be using Piaranha's method of pack configuration when I put it back together.

Carl

[wcc963]

NEVER MIND GUYS I LOOKED AT THE SPECS, AND ITS WIRED IN SERIES.

i have a battery question im gonna be running 2 3S1P 2500mah lipos, are these wired in series or parallel? i know one would give me 6S power with 2500mah, and the other will give me 3S power with 500mah. so which one is it?

[bclong21]

series! If you run parallel you will double the amps but the voltage will only be that of 3s pack. Series wil add the voltage together for a combined voltage of the 2 packs of 22.2v. The mah rating stays the same in series also. I run 2 3s1p in series when I want aggressive flying and 2 3s2p when I want longer flights. 4 of the TP prolite 2100's fit nicely under the canopy.

[kgfly]

Seems to me that A123 are a bit of a challenge on the H550 because of the battery mount design. Pirhana found a solution but it involves a split pack which is a bit annoying. Otherwise they are a very attractive option since their capacity is a good match for this heli.

LiPos still provide a higher power/weight ratio. Consider this estimate:


Comparison of Hurricane550 LiPo and A123
========================================

FP 6s 2500 EVO 25 FP 6s 2170 EVO 25 AirTh 6s 2200 25C A123 7s A123 8s
----------------- ----------------- ----------------- ------------- -------------
Price (USD$) $190 $160 $140 ~$105 ~$120
Dimensions (mm) 127 x 39 x 40 112 x 36 x 48 113 x 30 x 37 108 x 54 x 70 108 x 54 x 70
Weight (g) 420 360 390 ~525 ~600
Nom. V 22.2 22.2 22.2 23.1 26.4
Loaded V 21-18 21-18 21-18 20-16 24-19
Capacity (mAh) 2500 2170 2200 2300 2300
Load rating (C) 25/35/50 25/35/50 25/40 16/33/50 16/33/50
Usable current (A) 47/66/94 41/57/81 41/66 37/76/115 37/76/115
Loaded V 3.5/3.2/3.0 3.5/3.2/3.0 3.4/3.2 2.8/2.5/2.3 2.8/2.5/2.3
Usable power (W) 990/1270/1700 860/1100/1460 840/1270 725/1330/1850 800/1500/2100
Usable energy (J) 42 36 36 40 46
----------------- ----------------- ----------------- ---------- ----------


Notes:
1) Loaded voltage estimated from published discharge curves

2) Usable energy indicates runtime. Assumes max 80% discharge for lipo, max 90% discharge for A123

3) Usable current/power is based on keeping pack temperatures below 140F/60C to ensure maximum
pack lifetime (>100 cycles for lipo, >500 cycles for A123). For LiPo this typically means
staying below 75% of rated current. For A123 lab tests show that it means sticking to a
rating of 16/33/50C. If you are happy with only ~100 cycles from the A123 packs then you can
push them somewhat harder than the estimates indicate.

The estimates show that for a fairly small weight penalty, 7s A123 gives you a reasonable match for a 6s ~2200 lipo setup with slightly more energy to help make up for the weight, probably delivering similar runtimes. Going to 8s gives you a boost in energy and peak power while staying comfortably within the long-lifetime boundary.

Note that the lipos are definitely more powerful AND lighter, so if the ultimate in performance is your goal you have to go lipo. However if you use all that power the lipos will last far fewer cycles than the A123 setups so you cost per flight will be much higher.

I think if a clever battery mount modification can be worked out that will allow a single 7s/8s A123 pack to fit comfortably and still balance, it would be a great combination on this heli.

Good chargers for A123 packs of this size include the eStation BC8, eStation 902 + 2xPB6 balancers, Hyperion 1210i + 2xLBA10 balancers or TP1010+210V balancer. I like the BC8 since it is an integrated balance charger, much more convenient.

One advantage of going with split 3s+4s or 4s+4s packs is that you can charge them on a CellPro4S ($75, 3s@4A, 4s@3A).

[dutch_anykey]

Thanks for the report :D

This luckally confirms my choice for the A123. I'm not a hot flyer...I made one mistake i think. I ordered a CC P80 Esc. I was better of buying the HV version of CC because of cell count. That way i could go for 8s A123 later on. I don't think the cc P80 will deal for a long time on 8s voltage even if it is A123 and not lipo

Maurice

[kgfly]

I would think about a 10S setup with this heli "when" I get one, I am just not sure if its gonna be 10s1p or 5s2p
10s will be quite a feat to fit on this heli, I look forward to your build thread *with photos please* :D

The weight penalty is getting up there at around 750g vs under 400g for typical 6s lipo, about a 15% increase in AUW. Perfectly managable for a heli this size of course, especially with the mountain of power it will provide.

[Cryofix]

if this is in fact a true 30 size heli I can use my Logo power system with this heli, Z30A-800 with a CC45HV I will need to look into gearing for 2500 head speed, but... in another thread they are saying that the 2500's can not handle the power needed and they are looking into the 3300 packs which would bring the weight up a good bit.

700 grams plus shrink, leads and taps, about 725 grams per pack for 10S so it may be a half pound difference.

It will be a few weeks but I will have one soon, brakes and new tires come first.

[ozace]

I dont believe the hurricane design copes well with the extra weight of the A123 cells. The heli is better on lipo due to the small frame layout and "interesting battery mounting system.

[dutch_anykey]

Hi Guys,

Received my first batch with goodies yesterday :D I still feel like a little kid with Xmass when packages arrive hehe.
CNC blade grips and some other upgrade stuff. Also the A123 7s pack from infinitty-hobby came with it.
I know some people mentioned that this pack doenst fit under the plastic canopy...but i don't seem to have any problem with it. The end of the pack is just lighty pusing against the canopy...but nothing serious imop. Anyway if you have the FG canopy it should have no problem at all.

Anyway waiting for my other package to arrive. That one includes the eos12101-A charger including 2 balancers.

Maurice

http://www.helifreak.com/album_mod/upload/455c8c6ea4f6da6d526676d927397d28.jpg

http://www.helifreak.com/album_mod/upload/d670433b482392cfd9aa6116a40643d9.jpg

http://www.helifreak.com/album_mod/upload/3a37dfc1157a245fc1f28efc417cb4e5.jpg

[quickster47]

dutch_anykey,

My A123 packs fit just like yours but I guess it is a personal thing about the fit cause I am not happy with it.

I do have one of the packs disassembled and am putting it together like Piranha did his A123s.

Carl

[Tomas-]

I need an adapter cable to use my TP210 balancer with these A123 packs... anyone have an idea where I can find one? (Or just the connectors so I can solder one myself)

[dutch_anykey]

I just oredered a complete batch of balance connectors that will fit my EOS balancers. So i'm going to solder them to my packs. In that way they allways fit my balancers. I got annoyed with all the different "conversion" cables.
The apropiate balance connectors can be found everywhere i think. i got mine from aircraft-world.com

Maurice

[werew]

Could these a123 batteries be used in smaller heli's? Say a 3s config with larger mah capacity for a T-rex450?

[kgfly]

They are not available other than as a 2300mAh round cell weighing approx 70g. Due to the lower voltage per cell 4S is the minimum required for a T450. That means 4s 2300 16/33C at ~300g compared to a typical lipo 3s 2200 20C/30C at 180g. It will fly fine but is not well suited to aggressive 3D. There are some threads here on helifreak about folks that are happy flying their T450 on 4s A123 packs.