R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 10-28-2007, 10:14 AM   #31
Tech Elite
 
Join Date: Nov 2006
Posts: 4,324
Trader Rating: 24 (100%+)
Default

Well, seems to have been done. Don't knowthat it is dangerous.
BobWoodhouse is offline   Reply With Quote
Old 10-28-2007, 10:23 AM   #32
ROV
Tech Fanatic
 
ROV's Avatar
 
Join Date: Apr 2007
Location: Australia
Posts: 823
Trader Rating: 4 (100%+)
Default

Quote:
Originally Posted by BobWoodhouse View Post
Cain, if 13.2 volts is close enough, I have seen folks charging 4S A123's directly off a car battery with no "charger". Have you seen that? They just use some power cord as a slight limiter and they watch the voltage for when it is ready to top off. The charging is so fast that unattended charging is not required.
I remember 1988 that was a fast charger for a 7.2 nicad, just 10 - 15mins and she was done,,,,,,the cable was just like pushbike brake cableoh the days,,,,if you couldnt touch the batt "DING" readymy dad would even start the car for a super charge....... true..i want my hornet back....
__________________
TELL THEM ROV'S HERE AND HE'S RUNNIN WHEELS THAT ARE READY TO RACE !!!
CEO TRASH TALK TOURING HOME OF WA'S CHEAP TRASH PISSTAKES
AM PSYCLONE,HOTBODIES D4,NOVAK,LRP,HACKER,MEGA,EFLIGHT.JR,KOPRO,HITECH, SPEKTRUM,TRAKPOWER,OS,CDC,SWASHDRIVE JET,ZENOHA,WEMOTECH DUCTED,LIPO4GO,LOSI,KOKOM,CDC,5IVE,8IGHT,XXCR,LST,CASTLE
ROV is offline   Reply With Quote
Old 10-29-2007, 02:59 AM   #33
Tech Master
 
d4_racer's Avatar
 
Join Date: Sep 2006
Location: in the emergency room :-(
Posts: 1,479
Trader Rating: 6 (100%+)
Send a message via MSN to d4_racer
Default

Quote:
Originally Posted by joe of loath View Post
WOW thats dangerous. i heard it works for Ni-cad, but then they're like that. lithium requires a special charge sequence, which for the first 90% of the charge its fixed current, and the last 10% fixed voltage. so theyre only charging to about 90% anyway, as well as having basically a bomb! the car battery will be chucking 700 amps into them! thats alot of current! (and the wires will melt if you leave it for longer than a few seconds)

and D4, uranium isn't very reactive. one of the most is something like ceasium i think.
i've seen on a fair few forums that people use a 12v power supply at 3-4A output and direct charge from that and somehow the A lowers itself as the pack gets full or something odd. either way sounds dodgy, but a guy has been doing it for 20 years, so it must be working OK then.

aint uranium that reactive? i thought it was, oh well, you learn sumthin new everyday
__________________
\____
==\_\___===___ | *HPI Baja SS kit;*
==(@)\_______\(o) +UNDER CONSTRUCTION+
^^^^^^^^^^^^

out of racing, but a proud marshall, lol
d4_racer is offline   Reply With Quote
Old 10-29-2007, 03:52 AM   #34
ROV
Tech Fanatic
 
ROV's Avatar
 
Join Date: Apr 2007
Location: Australia
Posts: 823
Trader Rating: 4 (100%+)
Default

Quote:
Originally Posted by d4_racer View Post
somehow the A lowers itself as the pack gets full or something odd. either way sounds dodgy, but a guy has been doing it for 20 years, so it must be working OK then.
101 understanding voltage d4,,,,not dodgy,, sience of elecricty,,Capacitance ,,,learn it
start with understanding DC principles, you will need to know this for rov work.
__________________
TELL THEM ROV'S HERE AND HE'S RUNNIN WHEELS THAT ARE READY TO RACE !!!
CEO TRASH TALK TOURING HOME OF WA'S CHEAP TRASH PISSTAKES
AM PSYCLONE,HOTBODIES D4,NOVAK,LRP,HACKER,MEGA,EFLIGHT.JR,KOPRO,HITECH, SPEKTRUM,TRAKPOWER,OS,CDC,SWASHDRIVE JET,ZENOHA,WEMOTECH DUCTED,LIPO4GO,LOSI,KOKOM,CDC,5IVE,8IGHT,XXCR,LST,CASTLE
ROV is offline   Reply With Quote
Old 10-29-2007, 05:30 AM   #35
Tech Master
 
d4_racer's Avatar
 
Join Date: Sep 2006
Location: in the emergency room :-(
Posts: 1,479
Trader Rating: 6 (100%+)
Send a message via MSN to d4_racer
Default

Quote:
Originally Posted by ROV View Post
101 understanding voltage d4,,,,not dodgy,, sience of elecricty,,Capacitance ,,,learn it
start with understanding DC principles, you will need to know this for rov work.
i'll know this all when i do year 11 and 12 prolly and deffo when i go to uni. at the moment you learn stuff all in year 10 electrical physics.
__________________
\____
==\_\___===___ | *HPI Baja SS kit;*
==(@)\_______\(o) +UNDER CONSTRUCTION+
^^^^^^^^^^^^

out of racing, but a proud marshall, lol
d4_racer is offline   Reply With Quote
Old 10-29-2007, 05:36 AM   #36
Tech Elite
 
joe of loath's Avatar
 
Join Date: Mar 2007
Location: Bristol, England, United Kingdom
Posts: 4,857
Trader Rating: 1 (100%+)
Default

heh i self taught myself... i never learn anything in school now. maybe the odd little fact every lesson?
__________________
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 10-29-2007, 06:56 AM   #37
Tech Elite
 
JamesnMeyer's Avatar
 
Join Date: Oct 2006
Location: So Cal
Posts: 2,224
Trader Rating: 41 (100%+)
Default

The directions said to never start the car That was my fisrt charger, two cables with aligater clamps on one end and tamaya plug on the other. I used my hand as the peak detector and the cut off.

Quote:
Originally Posted by ROV View Post
I remember 1988 that was a fast charger for a 7.2 nicad, just 10 - 15mins and she was done,,,,,,the cable was just like pushbike brake cableoh the days,,,,if you couldnt touch the batt "DING" readymy dad would even start the car for a super charge....... true..i want my hornet back....
__________________
The Stadium at Pegasus Hobbies:tire:
JamesnMeyer is offline   Reply With Quote
Old 10-29-2007, 01:11 PM   #38
Tech Legend
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 29,535
Trader Rating: 240 (100%+)
Default

Does anyone know where I can see some pics of the A123's mounted in a 1/8 scale buggy?

I think the 13.2V setup would work fine, especially if I used a 2 or 1.5 Neu motor. I just want to see what it would look like mounted. to get an idea of what to try.
__________________
Member - Red River Radio/Control Car Club
< Tekno EB48SL / SCT410.3 | Tekno EB410 x 2 | Yokomo YZ-2 DTM x 2 | LC Racing EMB-1 Buggies and Truggies >
Cain is offline   Reply With Quote
Old 10-29-2007, 01:41 PM   #39
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

I would build 4, 4cell side by side packs in series. Then stack two packs on top of each other and wire them all in series. Then you can go and zip tie two packs down on each side of the car. If you are worried about them getting wet then zip tie them in a bag and fill the end of the bag w/ epoxy.
party_wagon is offline   Reply With Quote
Old 10-29-2007, 08:27 PM   #40
Tech Master
 
Join Date: Nov 2003
Posts: 1,850
Trader Rating: 5 (100%+)
Default

So, are the a123 cells from the Dewalt batteries 2400mAh each? I know they are 3.3v per cell, but wasnt sure about the mAh.
Stealth_RT is offline   Reply With Quote
Old 10-29-2007, 10:02 PM   #41
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

2300mah. A 4p pack will make a 9200mah pack.
party_wagon is offline   Reply With Quote
Old 10-30-2007, 07:45 AM   #42
Tech Legend
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 29,535
Trader Rating: 240 (100%+)
Default

With that won't be any problems making 30+ minute main. I am going to contact RC Product Designs and see if he has done anything for a mount to use these cells.
__________________
Member - Red River Radio/Control Car Club
< Tekno EB48SL / SCT410.3 | Tekno EB410 x 2 | Yokomo YZ-2 DTM x 2 | LC Racing EMB-1 Buggies and Truggies >
Cain is offline   Reply With Quote
Old 10-30-2007, 09:07 AM   #43
Tech Regular
 
Join Date: Aug 2006
Location: DeSoto MO
Posts: 255
Trader Rating: 37 (100%+)
Default

If you guys are serious about A123 cells, start checking forums that they are used on a daily basis.

www.rcgroups.com and www.runryder.com.

I personally use a Mastech powersupply and charge an 8s pack at 10amps, strait from the power supply. Its a CC/CV lab grade power supply.
rnpnick is offline   Reply With Quote
Old 10-30-2007, 11:11 AM   #44
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

Guys, these packs aren't like mounting a fuel tank. Go and build two 4s2p packs, wire them up in parallel and mount them in a location that will leave your chasis balanced how you want it. The easiest way to do this is take a fully fueled rtr nitro buggy and put a scale under each wheel. Now, measure the weight on each wheel. Now go and balance the buggy w/ the same weight ratio from wheel to wheel. So if ur rtr nitro has 2lbs on the front wheels and 2.5lbs on the rear wheels then make sure that the weight ratio is the same on the electric when you mount your batteries. You also want to make sure that the parts are as close to the middle as possible.
party_wagon is offline   Reply With Quote
Old 10-31-2007, 08:13 AM   #45
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

Alright guys, I just set up a mini inferno-t w/ these cells. I am running an a123 cell on each side w/ a mamba system. It delivers plenty of power for racing this thing too. I get a lot more punch then I was getting and top out at around 25-30 m.p.h. which is more then enough for racing these things off road. The cells also fit perfectly into the little battery boxes too. If you want more speed for bashing around then pick up that voltage converter that a123 sales and you can run w/ 10.8volts.
party_wagon is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
a123 racing Lithium Ferrite 30C 4600 packs poorbie:( Australia For Sale/Trade 4 08-24-2008 03:44 AM
a123, dewalt packs, new/used need quite a few cells poorbie:( Australia Wanted to Buy 0 04-29-2008 11:48 PM
A123 Brick Packs, Big News trailranger Electric On-Road 29 03-02-2008 08:58 AM
A123 battery chargers chumanji Radio and Electronics 1 01-31-2008 03:14 PM
A123 packs party_wagon R/C Items: For Sale/Trade 11 12-06-2007 10:28 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 10:51 PM.


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