Battery questions!

Lynxmotion
1

Hello all,

I’m going through the learning process of building/programing a hexapod for use in the Mechwarfare competition. Its been a huge learning curve but one of the issues I for see on the horizon is power source issues. Currently, all I want to do is increase the run time of the robot, so i’m not concerned with calculating draw from airsoft cannons and turret servo. This has raised a few questions that any advice/suggestions would greatly be appreciated. Please note: I do not mean to ask repeative questions or insult anyone’s intelligence, I’m very new at all this!

  1. I’ve been reading through the forums and notice that alot of people seem to use a UBEC (a Turnigy UBEC - 15a to be exact) to draw down the voltage to an appropriate amount. If i’m reading the specs correctly:

"Spec.
Output (Constant): 5v/8A or 6v/8A
Input: 6v-12.6v (2-3cell lipo)
Size: 42x39x9mm
Weight: 34g
Quiescent current: 60mA
Type: Switching, however because of the noise reduction (thin metal case & filter) this unit gives the same noise as a Linear BEC.

LED indicator (2 or 3 cell)
Full : 7.8~8.4v / 11.7v~12.6v
Incrimenting down to;
5.4~6.6v / <9.9v"

I should be able to connect ~12.6v LiPo and it will reduce to output down to <9.9v. Is this safe for the SSC-32 to draw power? Reading in the SSC-32 documentation it states:

“7.2vdc - 7.4vdc can be applied to HSR-5980 or HSR-5990 servos. This can be directly from a 6-cell NiMH batery pack or a 2-cell LiPo battery back.”

I’m currently running HS-645MGs (6vdc), but will be up grading to HSR-5990TG. ** Does this mean I cannot use the 12.6v pack until I upgrade the servos? I would instead have to use the ~8.4v LiPos?**

  1. I’ve also read on the forums that some people use two UBEC. Is that for 1 for the servos and the other to power the logics?

  2. What connectors (female/male) do you use with your LiPos? I’m seeing alot of Deans connectors, any performance differnce or safety issues between deans and the Tamiya (I believe those are the ones that come with the kit)?

Thanks in advance to any replies.

2

Hi,

I’ll try to answer some of your Q’s.
I’ve used the Turnigy for a long period of time and so far I’ve only managed to blow one of them and that was a “human error” :wink:

You must read what you are posting :wink: It’s the led indicator that indicate down to 9,9v. The output voltage are constant 5v or 6v.

I recommend using the regulated 6v for the 645’s. I’ve no experience of using a 2S LiPo on the 5990’s. But I think the peak of ~8,2-8,4v from a fully charged 2S might be a little to much for the 5990’s :confused:

I’ve used two regulators for all my robots so far. They both supply the servos. The main reason are for beeing on the safe side when it comes to peak current. There was a myth that said hexapods draw extremely high current… :laughing: Another thing is that the SSC32 has two power banks and that made it even easier for using two regulators. In theory I think/hope one regulator is enough though.

For robotics I believe any plug that are made for higher current would work. I’m using the Deans T-style plug that comes with the LiPo’s I’ve bought. I think the Deans are able to handle higher current than the Tamiya plugs, but for normal hobby robotics that is not a problem.

3

Thanks Zenta, its good to get confirmation don’t want to make a mistake and burn up a lot of money!

4

Hi,
I have to feed an esapode with 18 servomotores, I can use a battery 7,2 volts 3600 mahs NIMH.
To stabilize the 6 volts that need me I can use TURNIGY 8-15A UBECs, if it is possible as to do.
The battery is enough to make to move the robot.
robogeppo