servo amp draw?????????????
#1
servo amp draw?????????????
I have a futaba 3305 heavy duty servo, and I noticed in the specs it to only be used with ni-cd batteries, due to high amp draw. I'm confused. doesn't everyone run lipos in today's brushless powered vehicles, because the brushless ESC's draw a high amp current? Why wouldn't the same be true for servos? Are they saying the voltage of a lipo is to high, and this will burn up the servo? Please explain. If I do run this servo in a 1/10th scale buggy, using a 2S 4000-5000mAh lipo pack, what do I need to do? Should I run a voltage reg. and a power cap, and if so, which ones do you guys recommend? Thanks in advance, guys!
#2
I have a futaba 3305 heavy duty servo, and I noticed in the specs it to only be used with ni-cd batteries, due to high amp draw. I'm confused. doesn't everyone run lipos in today's brushless powered vehicles, because the brushless ESC's draw a high amp current? Why wouldn't the same be true for servos? Are they saying the voltage of a lipo is to high, and this will burn up the servo? Please explain. If I do run this servo in a 1/10th scale buggy, using a 2S 4000-5000mAh lipo pack, what do I need to do? Should I run a voltage reg. and a power cap, and if so, which ones do you guys recommend? Thanks in advance, guys!
#4
Tech Elite
iTrader: (5)
The 3305 is one of Futabas oldest servos still being made. Back when they were "high tech", battery technology was still a little lacking. The 4AA holders were the norm, and they weren't that good at supplying a lot of amps consistently. Once you strapped in a 5 cell NiCD pack it spread out the amp draw between 5 cells instead of 4.
#5
The 3305 is one of Futabas oldest servos still being made. Back when they were "high tech", battery technology was still a little lacking. The 4AA holders were the norm, and they weren't that good at supplying a lot of amps consistently. Once you strapped in a 5 cell NiCD pack it spread out the amp draw between 5 cells instead of 4.
#6
Tech Champion
It's also my understanding that the warning is for smallish nimh receiver packs, as they began to replace nicad packs, most commonly used with nitro RCs. I wouldn't expect any issue with an electric RC. I don't have that model servo, but I have many Futaba servos that have the warning that work great in my electrics, without any glitch buster or other aids. With either nimh or lipo main packs.
#7
Tech Champion
Ummm a 5 cell pack has the cells in series so the packs ability to deliver current remains the same between a 4 or 5 cell pack. I think you meant to say the servo performed better because you went from 4 AA nicds at 4.8v to 6v 5 cell nicd thus increasing the voltage and lowering the servos requirement for current. Higher supplied voltage less demand for current (ohms law)
In the general case the higher voltage/less current deal only happens if the power is maintained at the same level. Which usually requires a change in the load. With the same load, higher voltage drives higher current.
#8
Thanks guys! I'm selling some of my RC stuff, to fund my full size car. I was building a street stock for the dirt oval, out of a B3 buggy. My friend is wanting to by the car, and wants me to include a servo with it. It's the only metal gear servo I have, that I wasn't wanting to hold onto. I don't like to sell things, if I'm not sure about them. Thought I'd check with with the experts, before I sold him something that he'd have problems with later.