My 1.6m Monolog 70 has HS-7975HB on all four. They have specified operating voltage of 4.8-6.0V. My ESC has a programmable BEC.

Is there any reason not to up the voltage from 5v to 5.5v or 6.0v?

I'm not sure if would benefit or not. The servos are all standard size and some planes that size uses mini servos, at least for the ailerons. So I might already have enough servo power.

-Ken aka l2t

from what I know and learned servos rated for 6v are based on the fact that a 5cell NiMH pack will charge to 6.6v at peak so servos can handle that. 7v is too much so a 2s lipo at 7.2 and peaks at nearly 8v would burn the servo eventually.

I have my castle becs set for 6 volt!

I personally would not operate a model this large on BEC. A 500 mah LiFe battery weighs very little and is a great voltage to operate at.

My solution is to run the BEC at 6.0 volts and have a 500 mAh 2s LiPo (about one ounce) backup battery regulated to 5.7 volts. As long as the BEC is working it provides all of the current. If it quits, the backup pack takes over and you save your airplane. Check the backup pack once in awhile and charge it if necessary.

Jim O

It sounds like your system works like the Scorpion guard, it's just DIY. May I ask what you use for a regulator?

I use the Jaccio. Available at F3A Unlimited.

Jim O

If all your servos and the RX are rated for 6v, by all means use 6v.
BEC's generally work with slightly less heat dissipation at 6v, and may be able to provide
just a bit more current.

Naturally, you can have servos that were over rated by the mfr for marketing reasons,
and may eventually have problems at 6v. If this is a possibility, 5.5v might be safer.