Talk to me about battery care

[phantomoftheopera]

I always read about people adjusting low voltage alarms, checking individual cell voltage immediately after flights, etc.

Can someone give me a rundown of proper battery care or point me in the direction of a good tutorial?

My main questions are:

What is the interaction between the Assistant Software and the battery alarms?
What is the appropriate voltage to drain a battery to?
What is a good voltage checker?

Any other advice?

Thanks!

 

[reALIGNed]

Pull up a chair..........

http://helifreak.com/forumdisplay.php?f=31

 

[phantomoftheopera]

Pull up a chair..........

http://helifreak.com/forumdisplay.php?f=31

Thanks for the link! I have been reading a lot lately.

I still have a question regarding setting the First Level Protection setting in the Naza Assistant. How do I determine the voltage to put as the No Load First Level Protection trigger?

I understand you never want to take out more than 80% of the voltage or get lower than roughly 3.6 volts per cell.

If I have the Mad Dog 2700mAh battery how would I calculate the No Load voltage?

Thanks in advance!

 

[socman]

Pull up a chair..........

http://helifreak.com/forumdisplay.php?f=31

Thanks for the link! I have been reading a lot lately.

I still have a question regarding setting the First Level Protection setting in the Naza Assistant. How do I determine the voltage to put as the No Load First Level Protection trigger?

I understand you never want to take out more than 80% of the voltage or get lower than roughly 3.6 volts per cell.

If I have the Mad Dog 2700mAh battery how would I calculate the No Load voltage?

Thanks in advance!

the mAH does not matter...its how many cells you are using. In your case, all batteries you use to power your phantom are 3 cell. 4.2V per cell is fully charged (or 12.4V per pack). If you use the 80% rule, you do not want your pack dropping below 9.9V....or 3.3V per cell (assuming all cells are balanced).
So having your first protection at 3.6V per cell (or 10.8V as a pack) is actually not a bad idea to keep it at. That way you have time to get it landed and such.

 

[ElGuano]

Pull up a chair..........

http://helifreak.com/forumdisplay.php?f=31

Thanks for the link! I have been reading a lot lately.

I still have a question regarding setting the First Level Protection setting in the Naza Assistant. How do I determine the voltage to put as the No Load First Level Protection trigger?

I understand you never want to take out more than 80% of the voltage or get lower than roughly 3.6 volts per cell.

If I have the Mad Dog 2700mAh battery how would I calculate the No Load voltage?

Thanks in advance!

the mAH does not matter...its how many cells you are using. In your case, all batteries you use to power your phantom are 3 cell. 4.2V per cell is fully charged (or 12.4V per pack). If you use the 80% rule, you do not want your pack dropping below 9.9V....or 3.3V per cell (assuming all cells are balanced).
So having your first protection at 3.6V per cell (or 10.8V as a pack) is actually not a bad idea to keep it at. That way you have time to get it landed and such.

Small arithmetic niggle- full pack charge is 12.6v, not 12.4. Also, it's not preferred to think about percentages in voltage. Voltage drop is non-linear, particularly near the beginning and end of the discharge curve. 3.3v per cell is not 20% charge remaining, at constant runtime and drain. Once it drops to 3.0 at load, it really falls off a cliff. Iirc I put 20% closer to 3.57-3.58v/cell loaded.