Hey, I'm having trouble deciding which battery to use for a project.

I'd like to run an ATtiny and two motors at ~500mA for extended periods of time, while keeping the battery as light as possible.

I was looking into Energizer's lithium ion AA batteries, which, at 3000mAh, could power my setup for around 4 hours using only two cells.

Other than this option, I've thought about rechargeable batteries, however I'm just not sure which to choose out of the hundreds available. I'd like something ~5v with a capacity of 1000-2000mAh, but I'm not sure if I can get this.

Anyone have advice?


Why not use a Li-Po(Lithium Polymer) battery. I mean, I have used then before on projects. How much time do you need it to run. You could use a 3000 mAh 2s(7.4 Volt) Li-Po battery. They may be a bit costly, but they work awesome. Mine weighs about 150 grams. But before buying it wait for more advice.

Cell phone charger battery packs (power banks) output 5V, can supply current in excess of 1 to 2A, can be charged with USB and come in many mAh capacities.

Firstly,what project are you on?

I suggest you to use a power bank with a capacity of 5000-10000 mAh and current of around 2-4 Amps.

Here is what I found as the best option for your requirement:

Power Bank Options-Amazon

It has:

  • A good Capacity
  • A good Amperage
  • Low weight-8 ounces or 226.796 grams
  • A comparatively good price.

I would mention a potential problem when using those charger bricks. The one that I have will shut down if the current draw becomes less than about 30 mA for about 10 seconds (ie the device is fully charged). Your circuit draws enough that it should not be a problem, but I think it worth mentioning.

Yes indeed, that is a problem.

I run my Mega ADK with a 5 V ;1 A ;2600 mAh power bank. And in sketches which involve low processing and output it switches off.

But this is not a problem, it is just RARE.

I found that, with my pack, that I need to draw the 30mA only briefly (20 milliseconds) every 8 seconds or so to keep it turned on. I just pulse an LED to draw the extra current (15mA in my case).

groundfungus: I just pulse an LED to draw the extra current (15mA in my case).

Yeah, that sounds better....