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What power sources have worked the best?
I am using one 7.2V 3000mAH battery pack for each of my arms that plugs into a sensor shield on the Arduino (5 servos drawing from each pack)

Currently, we are using 8 AAA batteries to power 6 servos and a laptop to power our arduino with a USB cable

windu34 wrote:What power sources have worked the best?
I am using one 7.2V 3000mAH battery pack for each of my arms that plugs into a sensor shield on the Arduino (5 servos drawing from each pack)

It doesn't make much of a difference, but I recommend LiPo batteries. They are a bit more expensive, but they supply much more constant current, hold their charge better, and have a longer life span. In practice they minimize servo/motor jerking and are very reliable. Just remember that LiPo BATTERIES ARE ILLEGAL ON PUBLIC AIR FLIGHTS, meaning that you have to either ship them or drive them to nationals.

Bazinga+ wrote: Just remember that LiPo BATTERIES ARE ILLEGAL ON PUBLIC AIR FLIGHTS, meaning that you have to either ship them or drive them to nationals.

This isn't true. You can't put Lithium batteries in CHECKED luggage, but you are allowed to put them in you CARRYON luggage. You can bring as many batteries that are less than 100 Watt Hours, and 2 batteries per person that are between 100 and 160 Watt Hours. See http://phmsa.dot.gov/safetravel/batteries

chalker wrote:

Bazinga+ wrote: Just remember that LiPo BATTERIES ARE ILLEGAL ON PUBLIC AIR FLIGHTS, meaning that you have to either ship them or drive them to nationals.

This isn't true. You can't put Lithium batteries in CHECKED luggage, but you are allowed to put them in you CARRYON luggage. You can bring as many batteries that are less than 100 Watt Hours, and 2 batteries per person that are between 100 and 160 Watt Hours. See http://phmsa.dot.gov/safetravel/batteries

Oh thanks didn't know that. Any idea why it's like that? I don't see why having it in carry-on would be any safer (I mean I guess luggage could roll around or something).

Bazinga+ wrote: Oh thanks didn't know that. Any idea why it's like that? I don't see why having it in carry-on would be any safer (I mean I guess luggage could roll around or something).

It's easy to screen carry-on luggage to make sure there aren't too many batteries being carried on. It's harder to do that with checked luggage. There have been several fires in cargo holds of airplanes as a result of lithium batteries. The halon fire suppression systems in cargo holds also can't put out lithium battery fires (but the assumption is that people would be able to put out a small fire in the main cabin with water or something else.

I am currently using a 7.4 Volt battery to power 5 servos. The recommended voltage for the servos is 6 volts but the closest thing I could find to 6 was 7.2 and 7.4 volt batteries(like 8.5 when fully charged). I've had a lot of servos burn out and I'm wondering if this is because I'm running it at a higher voltage, or just that I was putting too much strain on them or they were stalling for too long. If the problem is the high voltage does anyone know where I could get the right voltage rechargeable batteries with decent storage. I would like to stay away from voltage regulators.

Bazinga+ wrote:I am currently using a 7.4 Volt battery to power 5 servos. The recommended voltage for the servos is 6 volts but the closest thing I could find to 6 was 7.2 and 7.4 volt batteries(like 8.5 when fully charged). I've had a lot of servos burn out and I'm wondering if this is because I'm running it at a higher voltage, or just that I was putting too much strain on them or they were stalling for too long. If the problem is the high voltage does anyone know where I could get the right voltage rechargeable batteries with decent storage. I would like to stay away from voltage regulators.

It's most likely the high voltage. I found 6V 4200 mah battery packs on servocity for my non-brushless servos.

Thanks!

chalker wrote:

Bazinga+ wrote: Oh thanks didn't know that. Any idea why it's like that? I don't see why having it in carry-on would be any safer (I mean I guess luggage could roll around or something).

It's easy to screen carry-on luggage to make sure there aren't too many batteries being carried on. It's harder to do that with checked luggage. There have been several fires in cargo holds of airplanes as a result of lithium batteries. The halon fire suppression systems in cargo holds also can't put out lithium battery fires (but the assumption is that people would be able to put out a small fire in the main cabin with water or something else.

Doesn't Lithium react violently with water?