How to power Spark with double A batteries?

General
1

I was wondering how to power my spark core using double A batteries?

2

@1rudster In the documentation it talks about how to power the core.

While it doesn't mention AA batteries there, it does mention this:

If you so desire, you can also power the Core with 3.6V to 6V to the VIN pin, or 3.3V to the 3.3V pin.

AA batteries typically have a voltage of 1.5v for alkaline batteries and 1.2v for rechargeable NiMh batteries.

If using alkaline, 3 batteries would be enough to give you about 4v. You'd want 4 batteries if using NiMh to get about 4.8v.

3

ran mine off 4xAA this morning, works fine.

4

Thanks! But since I’m still learning hardware, how do i physically attach the batteries to the bread board? I imagine I need some type of battery case and a nine volt battery clip?

5

Hey @1rudster,

Good question, I think people will often use a battery holder for this kind of situation. I’m also getting familiar with the hardware side of things, but I think I’ve seen people use holders like this:

You could plug the wires from that straight into a breadboard or the VIN/GND on the core I think. (Someone please correct me if I’m wrong :slight_smile:

1 Like
6

Yes, that’s right - red wire to VIN and black to GND.

Or… As VIN and GND are adjacent pins, you could plug one of these straight in http://www.ebay.co.uk/itm/C1202-7-RC-Battery-Holder-Case-Box-Pack-4-AA-JST-2-Pin-/400429039010?pt=UK_ToysGames_RadioControlled_JN&hash=item5d3b6e3da2

2 Likes
7

Thank you everyone for the advice!

1 Like
8

I have 4*AA holder that has only USB port in it. It says 5V DC, but doesn’t really have any voltage management and gives up to 6.4V with full AA non-rechargeable batteries.

I wouldn’t use that to power a random usb device (eg. smart phone or Android TV-stick), but I have trying to read Core schematics and it seems to me that Core can handle 6V from USB as well as from vin. It has no datalines attached, so everything should go through Core’s power regulator?

9

All, I’ve discussed this with @zach in other threads and there is a warning you should be aware of when using AA cells:

If bypassing the regulator (i.e. powering the core by connecting the cells to the 3.3V pin), it may not be wise to exceed 3.6V, because the wifi module could theoretically be damaged. So if doing this, even 3 x rechargeable cells could cause damage, because that would be 3.8V.

If not bypassing the regulator (i.e. connecting the cells to the Vin pin), then 3 x rechargeable cells may not be enough to power the core. Even if they are enough, as soon as the cells begin to run down, the voltage may no longer be enough, leading to very short battery life.

However, powering the core via the regulator (Vin pin) with 4 x rechargeable or 3 or 4 x non-rechargeable should be fine.

If you want to maximise battery life, avoid regulators altogether, as they can waste a lot of power. Use a DC-DC converter instead, adjusted to 3.3V, and byass the regulator. They claim to be UP TO 98% efficient (although that’s a bit like claiming a shampoo leaves your hair “up to 99% dandruff free”!).

Paul

2 Likes
10

I have used 4 AA batteries connected to the VIN and ground pins and that has worked just fine for me.

1 Like