Battery droped below 3.0V, while tweaking 450 pro

[HackAttack]

So i just now found out that I'm not supposed to let my batteries go below 3.0V, so i was just tweaking my T-Rex 450 and the heli just stopped fully working, totally dead battery, i went ahead and charged it back but haven't used it yet, now is this battery damaged and does anyone know what would be the approximate voltage left in a battery when the heli dies? Another thing i heard is that you can make the ESC cut off at a certain voltage, but with the stock ESC for the t-rex 450 pro there isn't anything i can find out about it having a cut off voltage, anyone know if there is one with the stock ESC?

[airjawed]

Originally Posted by HackAttack

So i just now found out that I'm not supposed to let my batteries go below 3.0V, so i was just tweaking my T-Rex 450 and the heli just stopped fully working, totally dead battery, i went ahead and charged it back but haven't used it yet, now is this battery damaged and does anyone know what would be the approximate voltage left in a battery when the heli dies? Another thing i heard is that you can make the ESC cut off at a certain voltage, but with the stock ESC for the t-rex 450 pro there isn't anything i can find out about it having a cut off voltage, anyone know if there is one with the stock ESC?

Every time you go low in voltage it 'damages' the lipo. The voltage varies based on chemistry and the load so that is a bit tricky to say and hard to find those numbers. But I have found that resting voltage of 3.7/cell is a decent ballpark.

Do a search on the 80% rule for the generally accepted usage of lipos.

The stock ESC has a cutoff but it is only for cutting off power to the motor. It does not cut off power to the servos. I have not seen any ESC's that cut off power to the servos and it is for safety reasons. In flight you would rather damage a battery than loose control of the heli and cause injury/damage.

[HackAttack]

Originally Posted by airjawed

Every time you go low in voltage it 'damages' the lipo. The voltage varies based on chemistry and the load so that is a bit tricky to say and hard to find those numbers. But I have found that resting voltage of 3.7/cell is a decent ballpark.

Do a search on the 80% rule for the generally accepted usage of lipos.

The stock ESC has a cutoff but it is only for cutting off power to the motor. It does not cut off power to the servos. I have not seen any ESC's that cut off power to the servos and it is for safety reasons. In flight you would rather damage a battery than loose control of the heli and cause injury/damage.

Yep true i would rather lose a battery then have a crash, so i guess i would need to find out the amount of time of flying it takes to get down to 3.0V and then just make sure i end my flights by that time

[dmatthewb]

Or... You can mount a "lipo alarm" which will give you a visual or audio warning. I personally have a red light that comes on telling me when it's time to stop flying so that I don't over-discharge my batt. Got it at my lhs. Very small and light. Wires directly into the batt. PM me if you would like the website of the mfg. that makes the one I have.

[suresharp]

Hack in your manual for the 450 you have the setting for the ESC. You can set ESC to have a cut of at 3.7 or higher. You can pick up a digital cell reader so you know what each cell is at before and after charge You should all see Finless video on set up of ESC. The rule is you must leave 80% of battery power after flight. You must find out how many mAps your model uses per min. This way you know how long to fly before you drop below 80% battery and start to kill it. You then can set timer on tx to help you know how much time you have to go and when to land.

[suresharp]

Just a further suggestion after reading your post further. Pick up NmH batery pack you can plug in to rx so you can run everything except motor. They are 4.8 v and I use 2300mAh recharge able. if you use your pack you should be unpluging your motor for safty.