[D1gger]

I just finished my pack and it's currently powered by 8 AA alkaline batteries. It's running a crix wand light kit, GBFans soundboard, powercell board and a spongeface cyclotron booster kit. It works very well and I am very happy with it, but I was curious what kind of run-time I can expect from the AA's. I have them in an 8 cell holder stashed in the booster tube and it works so slick that I really hope it runs long enough to be worth it...

[CountDeMonet]

It really depends on the amp draw and the type AA used. If you have a multimeter it's easy to figure out the amp draw. Duracell has some nice data sheets on their batteries that can help with a guestimate.

https://www.duracell.com/en-us/techlibr ... ata-sheets

Once you know the current draw you can guestimate based off the service life graph in the PDF. Rechargeables will have a different service life.

I'll be using g a 2500mah 11.1 lipo in my pack. I've got a ton of those from my ex helicopter days and should last a very long time but I won't know exactly how long until everything is done and I know the current draw.

[D1gger]

I have a multimeter and have tried measuring amp draw, but the results are erratic and I'm not sure if I'm getting an accurate reading. The screen says mA and the baseline with just the lights going is just under 4, with the sound kicking on powerup it jumps up to 30 or so, but is very erratic. I'm not really getting a clear enough reading to judge total amp draw. Any suggestions on measuring it?

[D1gger]

According to those charts you linked to, even estimating 100mA, that should give me up to 15 hours till dead. does that sound right?

[CountDeMonet]

As lights turn on and off the draw is going to change so it's not unusual for it to bounce around. That is a really low current draw. You should get a good amount of time on that. The speaker is going to be your biggest draw so crank it up and find out what the worst case scenario is.

My PKE meter draws 55-65mA for the arduino, 14 led's, LCD screen, and a buzzer. In my setup the servo is the biggest pull and can spike to 150-160mA when that thing is moving. 1 LED should be pulling between 10 and 20mA for a decent brightness. I have to take into account the voltage where the arduino shuts down so I look for that shutdown voltage in the curve and that's my time. I estimated with the 4 AAA's I'm using and a good bit of usage of the servo I'd get between 4 and 5 hours of runtime and that's pretty close.

[D1gger]

I used alligator clamps to connect my meter in a little better and tried again. This time running just lights had the draw between 3-12mA with occasional spikes up to 20mA and firing the wand with volume at full blast showed anywhere between 100 and 200mA, but I never saw anything over 200.

What I'm getting from this is the lights will run seemingly forever, the sound at higher volume sucks the amps down faster and Duracell coppertop's should give me maybe 5 hours running lots of sound, more if I take it easy on the trigger and the song. I think I can live with that. We'll see about the real world application, though...

Thanks for your help and the link.

[WindDrake]

It really depends on the amp draw and the type AA used. If you have a multimeter it's easy to figure out the amp draw. Duracell has some nice data sheets on their batteries that can help with a guestimate.

https://www.duracell.com/en-us/techlibr ... ata-sheets

Once you know the current draw you can guestimate based off the service life graph in the PDF. Rechargeables will have a different service life.

I'll be using g a 2500mah 11.1 lipo in my pack. I've got a ton of those from my ex helicopter days and should last a very long time but I won't know exactly how long until everything is done and I know the current draw.

My pack has a Matty wand, Mattyblaster soundboard, GBFans Powercell/Cyclotron light kit, Bluetooth, and my proton pistol electronics and I get well over 24hrs of full-bore balls-out usage on a 5Ah 3S LiPo pack.

[D1gger]

Running my setup described above off of 8 house brand Radio Shack Alkaline AA's since the pack was completed and for a couple hours on Monday during a parade, keeping it lit up the whole time and only occasionally using the sound and they still measure at having 1.46 volts per cell average, which tells me I have another couple hours in them at least. That's close to the 5 hours I estimated and will probably be even longer running Energizers or Duracells. I think I can live with that until such time as I decide to pick up a 3s Lipo R/C pack.