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Topic: Arduino not running with Battery Pack?  (Read 2939 times) previous topic - next topic

StreetTripple

Mar 01, 2016, 08:18 pm Last Edit: Mar 01, 2016, 08:25 pm by StreetTripple
Okay, my project works completely fine whilst connected to the computer Via the USB connection.

FYI, my project is just an arduino with a gprs module and a PIR Sensor.

When I run it on 4 aa batteries in a power pack (fully charged), it doesn't work. Some components turn on and off and others don't work at all... Obviously the power is the problem.

I've ordered an 8aa battery power pack just in case that would work?

But I'm really stuck and it is needed urgently for an important presentation...

Thanks.

EDIT: Would a 9v battery work?

ieee488

Are you connecting your battery pack using Vin pin?

DrAzzy

What parts are you using?

What kind of batteries?

Rechargeable NiMH/NiCd batteries are like ~1.2V fully charged, so you only get 4.8v from 4 of them. When you connect those to the Vin pin, there's almost 2v of dropout (they didn't spring for a decent regulator), so you're getting more like 3-3.5v out of the regulator - yet presumably your parts are expecting 5v. Unsurprisingly, they don't work well.

If (and only if) your battery pack will never output more than 5.5v (which means, you will only ever have NiMH/NiCd rechargeables in it, never normal alkaline batteries), you can connect it to the 5v pin, and it'll probably work. Otherwise, a larger  stack of batteries is the solution - 6 cells of rechargeable NiMH/NiCd batteries, providing ~7.2v, would be ideal. A larger stack of cells connected in series would provide no benefit, since it's using a linear regulator, and that extra voltage is just wasted as heat.

The rectangular 9v batteries are no good - those put out a high enough voltage, but the current handling capability is abysmal. Under light loads, the battery life is just crappy, but if using with anything that draws much current, the battery voltage will drop like a stone the minute you try to get the current out of the battery (leading to the arduino resetting).
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StreetTripple

Thanks for the reply, solved it last night actually, but you got it.

I needed two extra batteries to make 9v basically.

However, I had an old portable usb charger which works great and can charge a phone for about a week... So yeah.

I'd rep you if this forum has it.

DrAzzy

Thanks for the reply, solved it last night actually, but you got it.

I needed two extra batteries to make 9v basically.

However, I had an old portable usb charger which works great and can charge a phone for about a week... So yeah.

I'd rep you if this forum has it.
Those USB chargers are great for this - lots of people use it. Be aware that some of them will shut themselves down when they don't detect a load, and some of them require enough current to register the device as connected that they'll turn themselves off when you use them to power a microcontroller board. The Arduino Uno is inefficient enough that it probably won't have this problem, but it's a real issue for boards that pay more attention to power efficiency and battery life.

Rep here is called Karma. They may not let people with very low post counts give it though, due to the potential for abuse.
ATTinyCore for x4/x5/x61/x7/x8/x41/1634/828/x313 megaTinyCore for the megaavr ATtinies - Board Manager:
http://drazzy.com/package_drazzy.com_index.json
ATtiny breakouts, mosfets, awesome prototyping board in my store http://tindie.com/stores/DrAzzy

RayL

I'm replying to this post for some clarification. I have an Infiduino R3 (it has a 3.3v/5v switch on it).
I set the switch to 3.3v because it connects to another board requiring 3.3 (powered from the Infiduino).
I want to power the Infiduino with a connection to the 2.1 mm barrel jack using a battery pack.
Should I be using 6 NiMH/NiCd batteries?
Thanks
Ray

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