Hitec 7950tg voltage

[ducatidesmo]

Hi,

Picked up a 7950TH and a CC BEC. I have the castle link so my question is should I run the full 7.2 volts (I have a 614 receiver so it can handle 8.4) or should I run a bit less?

Will running at the full 7.2 have an adverse affect on reliablity?

Thanks!

[AUSCRAWL]

Its rated to 7.4v. Heres the link to their site.
http://www.hitecrcd.com/products/dig...hs-7950th.html

[concretejungle]

i turned mine up to 7.4v and i don't know what was going on, but my entire rig would shut down and start up, shut down, steering would stop and come back on, ESC would stop and come back on... so i cut it back to where it was (stock) and it works great.

[Illeagle]

Originally Posted by ducatidesmo

Hi,

Picked up a 7950TH and a CC BEC. I have the castle link so my question is should I run the full 7.2 volts (I have a 614 receiver so it can handle 8.4) or should I run a bit less?

Will running at the full 7.2 have an adverse affect on reliablity?

Thanks!

I am also running the 614ff and a 7950. They are rated for 7.4v (2s lipo) but I have local buddies with factory support who actually run them at over 8volts. You will be fine running yours at 7.2 as you stated or 7.4 and running it through your 614ff. I personally am running mine at 7.2 through my 614ff and I have my OLP set down to 20%.

[Scattman]

Seems everyone forgets but a freshly charged lipo is not 7.4 volts.........................it is 8.4 volts fellas. 3.7 volts per cell is the nominal voltage.

I run my 7950 at 7.4 volts(1 volt less than straight off a fully charged lipo) through a 614 rec. with absolutely no problems.

[Scattman]

Originally Posted by Illeagle

I have local buddies with factory support who actually run them at over 8volts.

They are actually running them at a voltage close to what a charged lipo actually puts out when fully charged, 8.4 volts, which is still within specs although the lipo would gradually drop some voltage whereas the bec's they are running supplies the 8+ volts continuously throughout the run.

[ducatidesmo]

Originally Posted by Illeagle

I am also running the 614ff and a 7950. They are rated for 7.4v (2s lipo) but I have local buddies with factory support who actually run them at over 8volts. You will be fine running yours at 7.2 as you stated or 7.4 and running it through your 614ff. I personally am running mine at 7.2 through my 614ff and I have my OLP set down to 20%.

OLP??

sorry i'm a newbie, what's that?

[Illeagle]

OLP is the "OverLoad Protection" that you can set using a Hitec Hpp-21 programmer module. You hook it up to your PC and to your servo and you can adjust things like your center position, epa's, deadband, OLP, etc. Here is a link for some reading:

http://www.servocity.com/html/hpp-21...rogrammer.html

[ducatidesmo]

Thanks for the information, it's very much apprecaited.

Just read about the Castle/Hitec servos.. not very happy

[Grimreeper]

so are most people running the 7950 at 8.4? i am just about ready to swap my 7955 that is on 7 volts over to the 7950 and was curious about what to set it at. the 7955 worked great on my berg but when i switched to the xr it just does not cut it.

[irok22s]

8.4v here

[PowerCrazy]

did you pull the power wire from your esc?

[ev0l]

Just thought I would chime in with my experience. My 7950 on a CCBEC was also resetting and shutting down my Rx. It did this at 6v and 7.4. My BEC was pretty used so I bought a new one and everything seems great at 6v. I guess my old BEC couldnt take the heat.

[Charlie-III]

Originally Posted by ev0l

Just thought I would chime in with my experience. My 7950 on a CCBEC was also resetting and shutting down my Rx. It did this at 6v and 7.4. My BEC was pretty used so I bought a new one and everything seems great at 6v. I guess my old BEC couldnt take the heat.

Were you wired from the BEC direct to the servo, or through the RX??

[ev0l]

Originally Posted by Charlie-III

Were you wired from the BEC direct to the servo, or through the RX??

It did it wired both ways. The castle guys said it was caused by a ground loop. But even wired normally it did it. The new BEC was key for me.

[Charlie-III]

Originally Posted by ev0l

It did it wired both ways. The castle guys said it was caused by a ground loop. But even wired normally it did it. The new BEC was key for me.

What RX are you running? I don't have issues with Futabas, neither does my son (also Futaba).
I wonder if it's related to RX brand??

[DJB]

Excuse the ignorance from this question but I'm new to becs and the world of high voltage servos...

What's the deal with amp output from an esc to power a servo? Or is it just all about voltages?

Eg I'm building a kit, and want to know what gear to whack in my rig...eg Novak rooster crawler or tekin fx, mamba max pro etc etc. The problem is I already have a 7950th servo from hitec and everyone reckons it's a volt hungry beast that won't operate without a Bec? I've seen the diagrams to install one, my question is do I need to with any of the above three speed controls? And also, what amperage does a high voltage servo like this need to run at without shutting everything down?

Any help would be awesome, maybes there's another thread to anwser this, I couldn't find it haha.

[TexasSP]

Originally Posted by Scattman

Seems everyone forgets but a freshly charged lipo is not 7.4 volts.........................it is 8.4 volts fellas. 3.7 volts per cell is the nominal voltage.

I run my 7950 at 7.4 volts(1 volt less than straight off a fully charged lipo) through a 614 rec. with absolutely no problems.

Keep in mind that is resting voltage at 4.2 per cell, voltage under load is typically closer to (3.7 per cell) 7.4 for a 2s pack.

[Scattman]

Originally Posted by TexasSP

Keep in mind that is resting voltage at 4.2 per cell, voltage under load is typically closer to (3.7 per cell) 7.4 for a 2s pack.

Well of course the voltage drops some when under a load. And different loads will drop it to different voltages, 3.7 volts is not some magic number that all lipo's fall to when under load. Lot of different factors that go into it as well like pack mah and discharge rate.

[TexasSP]

Originally Posted by Scattman

Well of course the voltage drops some when under a load. And different loads will drop it to different voltages, 3.7 volts is not some magic number that all lipo's fall to when under load. Lot of different factors that go into it as well like pack mah and discharge rate.

Nothing magical about it at all. 3.7 is the minimum voltage a lipo should hold under load at the given c rate. This is how you get the c rate when coupled to mah. So if you have a 5000mah 3s 20c pack it should hold 11.1v at 100 amp discharge rate.