6 volt query

Works fine. I use 6V in all my planes. I use Futaba, JR, Airtronics, and Hitec. None of them seem to mind the extra voltage at all.

A small number of servos are not recommended for 6V operation. Most are fine.

John, where do you hail from?

Jerr

-- tailskid

Been modeling since '49 - which makes me an Old Fart

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Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

As CG said, MOST servos and receivers are fine with 6 volts, but check to make sure the equipment you are using is not in the group than will not handle it.

Also, when going to 6 volts, increase your battery capacity. While 6 volt systems provide more torque to the servos, they drain the battery faster. For example, if you are using a 600 mah battery at 4.8 volts, I would suggest going to a 1,000 mah (preferably 1,200 mah) battery for 6 volts. This will provide about the same amount of flying time before recharging is needed. If you will be using digital servos, go larger still.

| Also, when going to 6 volts, increase your battery capacity. While | 6 volt systems provide more torque to the servos, they drain the | battery faster. For example, if you are using a 600 mah battery at | 4.8 volts, I would suggest going to a 1,000 mah (preferably 1,200 | mah) battery for 6 volts. This will provide about the same amount | of flying time before recharging is needed.

Yes, going to 5 cell packs will drain your battery faster than it would if you stayed at 4 cells.

However, the effect is smaller than Ted suggests. Assuming that the radio gear has a fixed resistance, raising the voltage by 20% will increase the current by 20%. So to keep the duration the same, you'd need to raise the battery capacity by about 20% as well -- so instead of 600 mAh, you'd need 720 mAh.

However, in reality it's not quite that bad. Yes, the radio gear and circuitry in the servos does have an approximately fixed resistance, and so this assumption works well there. However, in most cases the majority of the energy exerted by the battery goes into the motors of the servos rather than the electronics, and in this case the resistance is not a constant. Yes, while the motor is running, it will use more current. But since it's running faster, it'll need to run for less time ...

In short, if you go from 4 to 5 cells, you'll need to add some extra capacity to get the same duration of flights. The additional amount needed is less than 20%, but you don't know exactly how much less, so just sticking with 20% is a good policy.

| If you will be using digital servos, go larger still.

Digital servos can use lots of power. (Because they try harder.) If you're using them, you probably want a larger pack anyways, 4 or 5 cells. But they still obey the rules I mentioned earlier.

Furthermore, a faster-running motor consumes less amperage per revolution because inductive resistance rises with RPM. The receiver might not take any more current at the higher voltage if it has a built-in regulator, as many electronic doodads these days have, so that reliable, consistent performance can be obtained as battery voltage drops. The circuits are usually designed to operate on some voltage lower than initial full-charge battery voltage.

Dan

John:

The first question is WHY do you want to switch? You need to read the info in the Battery Clinic:

There's alot of info on Red's site. Was there a particular piece of it one is supposed to read?