R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric Off-Road

Reply
 
Thread Tools Search this Thread
Old 04-05-2008, 11:03 AM   #1
Tech Regular
 
cm367700's Avatar
 
Join Date: Jul 2007
Location: carrollton, TX
Posts: 487
Trader Rating: 12 (100%+)
Send a message via AIM to cm367700
Default A123 cells?

do i need 6 cells to be equal to a 6cell pack?
__________________
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into
("')_("') your signature to help him gain world domination!!!!!!!
JUST DO IT!
cm367700 is offline   Reply With Quote
Old 04-05-2008, 11:47 AM   #2
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

two a123 cells in series is about like a very high end 5 cell nimh pack. 6 cells will give a 6.6volt 6900mah pack if you wire them up for 1/10th scale. You can wire them in parallel & that will increase the capacity.
party_wagon is offline   Reply With Quote
Old 04-06-2008, 09:34 AM   #3
Tech Regular
 
cm367700's Avatar
 
Join Date: Jul 2007
Location: carrollton, TX
Posts: 487
Trader Rating: 12 (100%+)
Send a message via AIM to cm367700
Default

can u charge them on like a ice charger or any other charger?
how should i mount them on a 4wd buggy(saddle)?
__________________
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into
("')_("') your signature to help him gain world domination!!!!!!!
JUST DO IT!
cm367700 is offline   Reply With Quote
Old 04-06-2008, 11:09 AM   #4
Tech Fanatic
 
Join Date: Jun 2006
Posts: 872
Trader Rating: 35 (100%+)
Default

Hey there. I run A123 cells in a saddle configuration in my bj4we. I am just running 2S1P and it lasts for an entire 6 minute main no problems. This is mod though. I have a 2s1p in stock, and it is a bit slow, but not bad though, I have won quite a few races even though I am a little slower down the straight. I am using a FMA balancepro charger to charge them.
__________________
High Desert Raceplace, Grand Jct CO, Sanwa Exzes Plus Stick Radio, Spektrum,Thunderpower 230g, Modified Tri-Nut Novak GTB2, Ballistic 4.5t 550, 5.83lb SCTE Ten, Novak Sentry Brushless Dyno, Crossweight Setup Station, Junsi 20A power supply Icharger 20A Charger,TP610C, 22B, Novak Edge, Novak 13.5, SC10, Havoc Pro SC XDrive, Ballistic 17.5 Matthew Joseph Cordova
mattnin is offline   Reply With Quote
Old 04-06-2008, 11:27 AM   #5
Tech Regular
 
cm367700's Avatar
 
Join Date: Jul 2007
Location: carrollton, TX
Posts: 487
Trader Rating: 12 (100%+)
Send a message via AIM to cm367700
Default

i have a 7700 so it will be fine cause i ran 5 cells with it and still it was ballistic. even on 4 cells!
__________________
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into
("')_("') your signature to help him gain world domination!!!!!!!
JUST DO IT!
cm367700 is offline   Reply With Quote
Old 04-06-2008, 12:06 PM   #6
Tech Regular
 
Join Date: Feb 2007
Posts: 397
Default

Quote:
Originally Posted by cm367700 View Post
can u charge them on like a ice charger or any other charger?
how should i mount them on a 4wd buggy(saddle)?
Yes the ice charger works on LI-ion and LI-po.
sght4 is offline   Reply With Quote
Old 04-06-2008, 12:08 PM   #7
Tech Elite
 
joe of loath's Avatar
 
Join Date: Mar 2007
Location: Bristol, England, United Kingdom
Posts: 4,857
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by sght4 View Post
Yes the ice charger works on LI-ion and LI-po.
A123 aren't regular li-ion cells. they are 3.3v/cell instead of 3.7v/cell
__________________
HPI E-Firestorm - Tamiya TA05 racer (carbon chassis, 10.5 brushless etc) - LRP Blast S10 BX - Revo 2.5r truggy conversion (in progress)
joe of loath is offline   Reply With Quote
Old 04-06-2008, 04:18 PM   #8
Tech Regular
 
Join Date: Feb 2007
Posts: 397
Default

Quote:
Originally Posted by joe of loath View Post
A123 aren't regular li-ion cells. they are 3.3v/cell instead of 3.7v/cell
yep your right, the ice crarger has no setting for a 6.6v LI-ION pack, so with that said, I won't be getting any anytime soon.
sght4 is offline   Reply With Quote
Old 04-06-2008, 05:21 PM   #9
Tech Regular
 
Buggy Brad's Avatar
 
Join Date: Nov 2007
Location: NewHampshire
Posts: 418
Default

I run A123's in my B44, as far as I'm concerned they are the best car cell on the market. Lifespan is 3 times more than any NICD/NIMH and 4 times more than lipo, they are very safe(no fire) and tolerant to overcharging and overdischarging. Cheaper than lipo but a little more than NIMH per cell but you need less of them so in the end it's cheaper. The voltage is a bit lower but the discharge curve is very flat so NIMH may have a bit more voltage to begin with but after a minute or so they will be about the same and then a few minutes after that the A123 will have more, lipo's have a fairly flat curve but not as flat as a123. If your running a low KV motor you might notice the lower voltage but with a high KV like the 7700 only the radar gun will know. Charge time is also great, the 2300mah cell can be charged at 10 amps so 15 minute recharges are no problem, I can produce some links that show them being fully recharged in 3.45 minutes over 350 times with only the slightest loss of capacity. As you can tell I love my A123's and a side note the 1100mah A123 cell work great in my associated RC18R........BB
Attached Thumbnails
A123 cells?-hpim1763.jpg01.jpg   A123 cells?-hpim1765.jpg03.jpg  
__________________
.....It's not a problem until it's on fire....
Buggy Brad is offline   Reply With Quote
Old 04-06-2008, 05:41 PM   #10
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

The best part about them is that you can hook them up in series when you charge them so you can still charge that 6.6 volt 6900 mah pack up in 15 minutes. Think about running for 20-30 minutes & charging in 15 minutes. Oh yeah, my 6.6volt 6900 pack set me back about 1/3rd of what a max amps 8kmah lipo would.
party_wagon is offline   Reply With Quote
Old 04-06-2008, 08:32 PM   #11
Tech Regular
 
cm367700's Avatar
 
Join Date: Jul 2007
Location: carrollton, TX
Posts: 487
Trader Rating: 12 (100%+)
Send a message via AIM to cm367700
Default

i dont really get about this series, parrallel stuff
__________________
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into
("')_("') your signature to help him gain world domination!!!!!!!
JUST DO IT!
cm367700 is offline   Reply With Quote
Old 04-06-2008, 09:08 PM   #12
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

Here is how I built my 6900mah 6.6 volt pack for my li//bl pro truck. 1st I took 2 cells & soldered the a + & - togather. Then I attached battery plugs to the other sides of the 2 cells. This makes a 6.6 volt 2300mah pack. Then I built 3 more of these packs. Then I attached 3 male deans plugs to my esc. You just take 3 deans plugs w/ wires & solder the + wire of all 3 to the + wire of the esc & the same goes for the neg. wire. When you plug the 3 6.6volt 2300mah packs into the 3 plugs it will combine their capacity & give you a 6.6volt 6900 mah pack. Then I went & built a wiring harness that uses 3 deans plugs. If you want to use a balancing plug then just go & solder one up to it as though the pack is a 6s pack when it is hooked up to the charger.
party_wagon is offline   Reply With Quote
Old 04-07-2008, 04:35 AM   #13
Tech Elite
 
joe of loath's Avatar
 
Join Date: Mar 2007
Location: Bristol, England, United Kingdom
Posts: 4,857
Trader Rating: 1 (100%+)
Default

series is with the positive of one cell soldered to the negative of the next, so it looks a bit like this:


+-+-+-
-+-+-+

this adds the voltage together, so a 6 cell ni-mh pack wired in series is 7.2 volts


parallel is with the positive wired to positive, negative to negative, so it looks like this:

- ---- -
++++++

this adds the capacity together, so 6 4500mah ni-mh cells will make a 27000mah 1.2v pack.

you can have different layouts of this, so a 6.6v 6900 pack is (i think, i'm not sure) 2 packs of 3 cells in parallel wired in series. so it would kinda look like this:

-- - +++
+++ -- -

so if you treat each parralel pack as one cell it would look like this:

+-
-+

hope that made sense...
__________________
HPI E-Firestorm - Tamiya TA05 racer (carbon chassis, 10.5 brushless etc) - LRP Blast S10 BX - Revo 2.5r truggy conversion (in progress)
joe of loath is offline   Reply With Quote
Old 04-07-2008, 07:28 AM   #14
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

a 3s 2p would look like this. The groups in paranthesis have a wire running from cell to cell. So, the three neg. at the bottom are soldered togather. The same goes for the other 3 groups in parenthesis. The groups in parenthesis are paralel which will add capacity. The group in brackets is also soldered togather. This will increase the voltage. The | repressent individual cells w/ the + & - as their ends. Then on the other side you have the two output wires that go to the esc. If these were a123 cells it would make a 2s 3p pack. or a 6.6 volt 6900 mah pack.




(++[+) (-]--)
|| | | ||
(-- -) (+ ++)
out out
party_wagon is offline   Reply With Quote
Old 04-07-2008, 11:43 AM   #15
Tech Master
 
RBMike's Avatar
 
Join Date: Jan 2007
Location: Santa Clara CA
Posts: 1,264
Default

I've been running a 2S2P A123 pack since September they work great, you just need a little more motor that you would use with lipo or nmhi. My pack (6.6V,4600mAh) will charge to 95% in 15 minutes with 10Amps, they never get hot & they will run my Novak 5.5 BL in the B44 for over 22 minutes at race pace.

http://i8.photobucket.com/albums/a43/RBMike/B44A123.jpg
__________________
-EMBX6,T8 1400, RX8, 5S Lipo ,Elite-RC, RCM tray
-EMBX6,T8 1350, RX8, 5S Lipo ,Elite-RC, RCM tray
-B44 (Novak)
-ROAR 4 cell rule Blows
RBMike is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
A123 CELLS cm367700 R/C Items: Wanted to Buy 0 06-25-2008 03:49 PM
A123 Cells Roar?? party_wagon Electric On-Road 20 02-05-2008 01:57 AM
charger for A123 cells chumanji Electric On-Road 7 01-06-2008 05:56 AM
A123 M1 Lithium Nanophosphate Cells FS GigaahX R/C Items: For Sale/Trade 11 05-11-2007 11:00 PM
A123 Li-ion 2 x 3s1p, loose cells K.Copeland R/C Items: For Sale/Trade 4 05-04-2007 10:23 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 10:20 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net