LiPo safe Voltage

[Nir]

How low do you go on your LiPo’s?

What is your Cut Off setting in the ESC’s?

[Agent CAL]

One thing I think I should make clear is it’s a dangerous thing to set a cutoff on the ESCs. One thing is one ESC might cut off before the others, but apart from that, when the ESCs do cut off, the tricopter will drop like a rock, and most likely result in a crash. I’d suggest getting some kind of telemetry system (Some systems have it built in to the receiver, while others (Spectrum for instance) you have to get a separate module.

If you don’t want to buy a telemetry system, you could hook up the battery voltage to the KK board, I think that has a beeper that will alert with a loud beeper when the battery is low, but as I have never done this you’d have to research it.

As for the actual setting, I set my system to 13.2 volts, which is 3.3v per cell. I got the info from FliteTest’s beginner series at around 5:10:

My Super Cub cuts off it’s battery at an even lower point (3.06v, but I think that’s really pushing it) with the stock system, so I think that a good voltage.

But there’s another thread in the “Everything Else” category all about this, and everyone else’s opinion differs from mine, so I’m not sure how accurate my setting is. You can find the other thread at http://rcexplorer.se/forums/topic/kk2-1-board-safe-battery-voltage-setting/#post-13214.

I’d like to hear what David’s voltage setting is, as I’m at something of a conflict as to when I should land.

[Nir]

Thanks!

Actually I have the Taranis with telemetry.
But I am using the T motors + T motors ESC’s http://www.getfpv.com/electronics/electronic-speed-controllers-esc/tiger-motor-s25a-600hz-2-6s-with-simonk.html
And I could not find a way to disable the Cut Off…

[_SYC_]

I don’t go below 20% remaining in the battery. Gives me around 15 minutes flight time on a 4S 3000mah.

Here’s a chart I made up to figure it out easily.

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   Lipo-Voltages.jpg
   

[Alan]

GAntojo recommended me a link on RChelicopterfun.com which has a section on Lipos, it explains everything. Don’t know how to put the link on here but its under the Lipo tab of the website. A must read.

[Agent CAL]

I see, that makes things clear. So, by running my batter down to 10%, it might not last as long. That’s good to know, I never knew where everyone typically stopped at. (Still would love to hear when David stops, even though it’s probably the same 🙂 )

[GAntonjo]

When I fly my APM clone (HKPilot Mega 2.7), with telemetry to my smart phone, I try to land when the Tower app on my phone alerts 30% battery. This is 10% above the recommended level, but when I come home and charge my batteries, I see that I manage to charge around 80% to the battery. So, for my 5000mAh I charge around 4000mA. The voltage on my 4S rices to 15V some minutes after landing. The voltage when flying gets down to 13.4V, according to the logs of my APM. The nice thing with the APM, is that it can calculate the battery based on used current, so when I have used around 4000mA this indicates 20% battery on my Tower App.

All in all, the 5000mAh 4S battery gives me 14-15 minutes of nice flight time.

[Freakazoid]

@GAntonjo
Which lipo do you use?

[Agent CAL]

@Freakazoid Well it doesn’t seem like it should matter much, as long as the cell count is the same, it’s a basic rule. Most brands of batteries obey a common voltage standard.

[Author]

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