Discussion A123 set up for a Trex 450?

[MTBsuspeng]

So I'm shopping around for a packs for my heli. originally I was looking at lipo pacs of the 3s 2200mah 20C variety, but these A123 cells are sounding better and better. I'm new to helis so a few extra grams isn't a big deal. Shorter charge time and higher durability out weigh higher discharge rates and lighter weight. I've been looking around for small helis set up with a123 cells and have only found a few. Is anyone out there running A123's on their 450? and if so what size and brand?

Thanks,

Ted

[n2wizard]

MTB
Try http://www.rcgroups.com/forums/showt...ight=a123+trex

Herman

[tronyony]

I have just switched to the A123 M1 2300mah cells in my Rex. Right now I'm running 4S1P packs. I have been getting between 7 and 8 min of flight doing FF, flips, rolls and ugly attempts at tic-tocs. The first flight was in my small back yard so all I could do was hover around and climb outs. I got about 9 min doing that. My setup is a very over weight Rex with JGF 450th w/13t pinion, Jazz 40-6-18 esc, medusa 6v bec, HS-81 mg's on cyclic and a 9650 on the tail. Even with all this weight it hardly bogs on climbout. head speed is at 2800 in normal and 3000 in idle up. The packs weigh 323 grams compared to my DN 3s 2150 lipos at 165 grams. My AUW is 2lbs 2.4oz. The funny thing is, it doesn't seem to mind it all that much. It is nice in the wind though. I flew it today in about 10-15 mph wind and all was well. I am no where near being ably to take advantage of a light setup for 3D so this is perfect for me. I tried to search for info on this myself and only came up with a couple of people who have done it and a bunch of nay sayers so I just did it. Happy I did. I charge them with my Astroflight 110DX with an a123 chip in it. Takes about 18 min to charge a dead pack putting back about 2200 mah.

Hope this helps,
Tony

[tronyony]

By the way, you can use this calculator to either figure out HS or pinion to use. Very helpful for me.

Tony

http://www.bladebusters.com/calculator.html

[highflier]

Originally Posted by tronyony

Happy I did. I charge them with my Astroflight 110DX with an a123 chip in it. Takes about 18 min to charge a dead pack putting back about 2200 mah.

Hope this helps,
Tony

Find charges thread on 10.00 charger.. It's for A123 cells 3s packs. If you gear up and drop voltage you can charge packs at the same rate you discharge them. 7-8 min charge.

There is also info about charging 2s or 4s packs if you look closely. That said you again you can charge at 15+ amps

Highflier

[deswong]

Originally Posted by tronyony

I have just switched to the A123 M1 2300mah cells in my Rex. Right now I'm running 4S1P packs. I have been getting between 7 and 8 min of flight doing FF, flips, rolls and ugly attempts at tic-tocs. The first flight was in my small back yard so all I could do was hover around and climb outs. I got about 9 min doing that. My setup is a very over weight Rex with JGF 450th w/13t pinion, Jazz 40-6-18 esc, medusa 6v bec, HS-81 mg's on cyclic and a 9650 on the tail. Even with all this weight it hardly bogs on climbout. head speed is at 2800 in normal and 3000 in idle up. The packs weigh 323 grams compared to my DN 3s 2150 lipos at 165 grams. My AUW is 2lbs 2.4oz. The funny thing is, it doesn't seem to mind it all that much. It is nice in the wind though. I flew it today in about 10-15 mph wind and all was well. I am no where near being ably to take advantage of a light setup for 3D so this is perfect for me. I tried to search for info on this myself and only came up with a couple of people who have done it and a bunch of nay sayers so I just did it. Happy I did. I charge them with my Astroflight 110DX with an a123 chip in it. Takes about 18 min to charge a dead pack putting back about 2200 mah.

Hope this helps,
Tony

How have you configured your packs? They look like a 2x2 setup, can you fit that under the canopy without any dramas?

I'm only asking because I am thinking more and more to move across to the A123's for the safety and price, I'm not planning on 3D stuff for quite a while and most other configs that I have seen the canopy needs to be cut to make them fit!

Regards,
Des.

[tronyony]

The packs are 2X2 and there is no problem for the canopy. It is a little tight but nothing major. When I return home from Iraq I am going to try 3S a123 instead of 4S do to this thread: http://www.helifreak.com/showthread.php?t=71462 I have the Scorpion -6 and 12T pinion awaiting my return from here. I'm no 3D pilot either but even with my current heavy setup it still flips and rolls nicely. 3S will make it a little lighter so that will be nice. Hope this helps.

Tony

[kgfly]

Most popular A123 setup these days for a T450 is indeed the Scorpion HK2210-6 (4400KV) with 12t/13t pinion and A123 3S 2300 pack. Most people look for a 40/45A ESC since this setup will burst over 50A. The 3S pack weight about 240g compared to a typical 3S 2200 lipo at 180g. the extra 60g isn't too bad and the 2210-6 has more than enough power to handle it (rated up to 540W!).

[raymond_h2002]

Seems like it'd be really nose heavy with 4s! I wonder how difficult it would be to balance out 323 grams??

-Raymond

[tronyony]

If I remember right, it is a bit nose heavy. A lot of that can be balanced out with the servo placement on the boom. It has been over 6 months since I have even seen my Rex so I could be wrong. All I can tell you is that it still flew good. 3S does seem like the way to go though. Not to mention the zip charge method (http://www.rcgroups.com/forums/showt...ght=zip+charge) for 3S and a DB Terminator(http://www.rcgroups.com/forums/showt...=db+terminator) appears to be great way to charge and fly. I ordered all the parts to construct the Terminator and am pretty excited to try it out when I get home.

Tony

[Eagleburger]

3S fits under canopy easily and is a touch nose heavy with a 9257 in standard position. I get 7+mins of hovering with a scorpion mentioned above.

I am in Brissy too and you can have a look at mine if you like. WHere do you fly?

[deswong]

Originally Posted by Eagleburger

3S fits under canopy easily and is a touch nose heavy with a 9257 in standard position. I get 7+mins of hovering with a scorpion mentioned above.

I am in Brissy too and you can have a look at mine if you like. WHere do you fly?

At the moment I fly in the front yard lol - I'm too scared to take mine up in the air.

I'm happy in the sim - but there is a small difference when you actually fly the real thing. I am sick of having expensive lipos swell up because I haven't used them in a while, looks like the A123's are a better solution for me - something I can charge quickly and easily without too much maintenance.

Also I can retrofit the A123's into my Roomba so it can zip charge too

I have learnt with the Lipos though, I have just bought two and will charge them once a week to keep them charged.

I am thinking I need a new esc (I've posted a thread elsewhere on the forums in regards to this) and I might as well look at the CC 45 and then upgrade the motor!

With the A123's why did you go vertical instead of horizontal?