# How to power project?

Hello,

I am building a vehicle that is controlled remotely. Now I use a external stabilized power supply (very heavy ) to test the circuit.

I use a Arduino Mega, 2 servo’s (5V) and two motors (5V).

How can I power the project as efficient as possible? I was thinking about a single 9V battery that runs trough a stabilizer and outputs 5V stable. But how much time will my project run on one battery?

Is it possible to combine multiple 9V battery’s to get more mA?

The problem is I don’t have got much experience on powering remote projects. So maybe one of you can help me out?

You need to provide more details, like how much current your rig draws, its size and weight, to give us some idea of what batteries it could carry.
You may be able to use a 6v battery & drop the voltage near enough to 5v using diodes instead of a regulator if stability is not that important.

If you can use 4 nicad or NiH cells, the 4.8v may be close enough.

Both the motors draw each 360 mA stall current.
The servos each draw 200 mA.
The Arduino Mega board draws approximately 500 mA.

So in total this would be 1620 mA maximum!

It will run for only several minutes before letting you down. 9V’s are rated at 625ma/h. With that much current, you might look into an 7v to 9v R/C Battery pack. These are very common and low cost. You should be able to pick up an R/C battery pack and charger for the cost of (8) 9v batteries.

if the batteries are the same Voltage, you can wire multiple batteries in paralell and use a Voltage regulator and some electrolytic caps to keep the DC voltage regulated.

i favor the LM78xx series, in your case, the 7805. u may also be able to use a Zener diode to regulate the voltage if the current specs are observed.

Those big lantern batteries are pretty decent with available power, your best bet may be to use Bigger single cell batteries, like C or D batteries in series banks of 4 to give you about 6 volts, and then paralell banks of those.

im not sure hoe big this vehicle is, but if the weight isn’t too big of a deal, larger cells would be the way to go.

also, the 7805 regulator if you draw over 500mA, you want a heatsink to keep it cool if you draw the full 1.5A

hope that helps!

Use two AA’s rated as high as possible * I have some 2800mAh ones) and use a mintyboost circuit to step it up 5v. The step-up IC does this very efficiently.

@ OpenSource: Are you sure about those figures? Did you accidentally include the servo current or some other load in the 500mA you quote for the Mega? I don’t have one, but 500mA sounds a bit high.
I don’t love the idea of parallel connected batteries- flirting with Murphy’s law!
Provided you don’t need the supply for the servos & motors to be really stable, I would suggest 4 D size Nicads or NiMH in series ßto run them, and a separate set of 6 AAs for the Mega. Connect the -ve of both sets to ground, of course. You don’t need any more regulators with this setup as the Mega has its own.
If you don’t want to go rechargeable, the lantern battery is a good option.

I was going to say the same !!!

Can`t see it going form 20 ma for the standard arduino to 500ma for the mega.
That is not a low power device which these devices are made for.
I think you are quoting the maximum current of the broad’s regulator not the running current.