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HeliProz . ZoomsHobbies . HeliHobby

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Radio - Servo - Gyro - Gov - Batt > A123's - Why use anything else?
 
 
jester4
Key Veteran
Location: Brampton, Ontario

I've been doing a lot of research in the last week about using these babies as RX power, and I've come to the conclusion that this is the best thing since sliced bread!!

I've decided to simplify my wiring and get rid of my arizona reg and lipo set up for a regulatorless a123 set-up. From my reading on flyinggiants, testing has shown that these things hold 2.95V @ 30A discharge through the entire pack. Under more sedate discharge amps, they can hold the 3.3 no problem, thus why use a regulator?

Under full charge, these can go to 7.2 V (talking 2 cell pack), and quickly drop to under 7 volts and settle at 6.6 nominal and stay there. The same voltages are found in 5cell nimh packs. All my servo's are rated for 6V so I see no reason why not. I've finished making my first 2cell pack, and I'm pretty excited to go ahead with the install and re-wiring into my 90, but I don't see much talk about them here as RX power. Am I missing something?

I plan to run the batt into a fromeco badger (high amp switch), then pigtail into 3 leads (AR7000 RX) that will go into the batt port, then into "y's" in the AUX2 and gain ports (running a multigov in the AUX2). I think this will give me more than enough amps available. Am I not seeing the problems or something? Tell me if I'm dreaming. Simple, high current, less failure points, safer technology....

NO SOUP FOR YOU!!
10-22-2008 03:20 PM
 
 
Eury
rrProfessor
Location: Ankeny, IA, USA.

All I run is A123s. Great packs, simply your setup (well, maybe not YOUR setup since you are adding in a ton of wiring etc), and they can charge at 10amps. Why run anything else?


Nick Crego
Still wanted by the government, I survive as a soldier of fortune.
10-22-2008 03:51 PM
 
 
nivlek
rrProfessor
Location: Norfolk England

What makes me laugh , is originally , when regulated set-ups first appeared , the main advantage was said to be consistant voltage flight after flight so servo speed and torque was the same on the last flight of the day as it was on the first .
Now people seem to have forgotten why regulators were originally used and just want to use higher and higher voltages with no regard to consistancy .
Whatever floats you boat .

At the end of the day , it gets dark .
10-22-2008 03:57 PM
 
 
jester4
Key Veteran
Location: Brampton, Ontario

Eury:

The only thing I am adding is 2 Y connectors for extra power to the RX, but removing all the regulator mess in the process. Based upon my research, 1 JR style connector can safely deliver 3 amps, so I figured if I ever needed the amperage, it's not enough. That's why I decided to use 3 power feeds, although I'm sure 2 would be enough.

Do you find consisitent flight performance from the start to the end of the pack? Does the machine feel sluggish towards the end of pack life? I figured with it's flat discharge curve it would feel somewhat "regulated"

NO SOUP FOR YOU!!
10-22-2008 04:31 PM
 
 
Eury
rrProfessor
Location: Ankeny, IA, USA.

The A123s stay between 6.6 and 6.7v the whole time until they dump. Absolutely no need for a regulator, the performance stays the same. Hot off teh charger they end up in the 7v region, but by the time I check all the controls, it's dropped and steady between 6.6 and 6.7.

Personally, I charge them after 5-6 flights on my 50s and put around 1100 - 1200 back in, and 4-5 flights on the 90 size and do the same. If you look at discharge curves, once your voltage drops, it's too late and you're crashing. My own tests have shown that with a constant 5amp load they sit between 6.6 and 6.7 for the first 2200mah of the pack, then in the last 50-100 they crash to 0 with no warning. You're better off being conservative, and a regulator will give you no advantage with regards to voltage consistency on these cells.


Nick Crego
Still wanted by the government, I survive as a soldier of fortune.
10-22-2008 06:02 PM
 
 
jester4
Key Veteran
Location: Brampton, Ontario

Awesome!!

Your observations are pretty consistent with what I have been reading all week. I'm pretty excited to give them a go.

NO SOUP FOR YOU!!
10-22-2008 06:38 PM
 
 
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Radio - Servo - Gyro - Gov - Batt > A123's - Why use anything else?
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