Servo speed-A123-Power Expan.

[rzubiria]

Hello All,

I just bought a Power expander 14MZ. Will be using it with a JR R1221 receiver and two A123 Fromeco batteries. I need a help on the following questions:

1. Do I need one or two switches?
2. I wont be using regulators. What will happen with the servo speed if on the first couple of flights the battery voltage will be higher than the voltage of the batteries at tthe end of the flying day. Having no regulators, the voltage will be lower at the end than at the beginning. Do you thing it will be perceptable this speed change? Having a higher voltage, the servo speed will be higher. After a few flight, the batteries will give a lower voltage so the spped will be lower. I would like to here comments about it.

Thanks,

[Bdegan]

	Quote: Originally Posted by rzubiria
	Hello All, I just bought a Power expander 14MZ. Will be using it with a JR R1221 receiver and two A123 Fromeco batteries. I need a help on the following questions:

I could not find any info on a Power Expander 14MZ. Could you post a link to it ?

	Quote: Originally Posted by rzubiria
	1. Do I need one or two switches?

Depends on the power expander and your set up. Need more info on this Expander 14MZ.
I use the Power expander Pro that has a soft switch. It eliminates the need for 2 switches. My battery packs are plugged directly into the power expander.
If the soft switch were to fail or become disconnected. The default for the Power expander pro is for the power to remain on. It won't turn off accidentally.

	Quote: Originally Posted by rzubiria
	2. I wont be using regulators. What will happen with the servo speed if on the first couple of flights the battery voltage will be higher than the voltage of the batteries at tthe end of the flying day. Having no regulators, the voltage will be lower at the end than at the beginning. Do you thing it will be perceptable this speed change? Having a higher voltage, the servo speed will be higher. After a few flight, the batteries will give a lower voltage so the spped will be lower. I would like to here comments about it.

with A123's regulators are not necessary. An A123 pack will have a slightly higher voltage off the charger. But within the first couple of minutes, the a123's will level off at 6.6 volts and stay there for a long time. If and when the voltage does drop. It will be signifagant and very noticable.
Chances are you will recharge before you every let a receiver pack get that low. Most people , myself included will top up the receiver packs after 4 or 5 flights at the field if you plan to continue with more flights. You can charge these batteries pretty aggresively and it shouldn't take more than 20 to 30 minutes to top up both packs.

[rrritchey]

Hi,
The above post covered a lot of the questions. The PowerExpander MZ can use either a failsafe switch, in which case you only need one, or you can use two mechanical switches, one on each battery. You should not see a big servo speed difference dropping from 7.2V to 6.6V.