My project consists of an Arduino Mini, a radio receiver, and a LED array that I am trying to run all off of a single battery pack. The issue is that each of these requires only 5V of current to run properly but if I put them all together, the current dips and some things stop working (such as the radio receiver).
My radio receiver only works within a 4.9 and 5.1V range so I have to be quite specific (I once accidentally put 9V through one and it burned out in seconds). Also, the Arduino shouldn't start to get faulty until the batteries are really dead so I can't go too low on that either.
I thought of putting 4 or 5 AA batteries through it all and putting a 5V regulator in front of each component. Then I read that the closer you get the the voltage regulators output, the lower the output actually is. This is a problem as the batteries start to drain obviously.
So, what is the best way to have enough voltage/current without burning anything out? I know the LED array would survive just fine with 6 - 9 V but I worry about putting more than 5.5V into the Arduino Mini 5V input and the same for the radio receiver.
There’s a “drop out” voltage which is around 1V (but see the spec for the particular regulator). You have to have at least that gap. So having 5 AA batteries should be fine, however once you have too many then the regulator starts to get hot. So you don’t want too few and you don’t want too many.
Another approach might be a boost-buck converter which would take your batteries and output a set voltage, even if the battery voltage is higher or lower than what you require.
I’m no expert on using them but it sounds good in theory.
Can you tell us what the existing battery pack is and what the individual loads are - or at least their current draws.
Its possible that several of the devices can run from the 5V output on the Arduino Mini - it sounds like the
LED module is tolerant of a higher voltage and doesn't require any regulation if the battery is of the right voltage?
A switching regulator (aka DC-DC converter) would probably help reduce losses and extend battery life as
has been mentioned, but with knowing what the existing battery or current requirements are its all guesswork
Well at the moment I am powering the Arduino Micro with a 9V and then powering the radio receiver off of its 5V output and then powering the LEDs with 4 AA batteries. I don't really like this since it doesn't do great stuff for the battery life (a few hours and the 9V is dead). I also don't want this to be super heavy with bunches of batteries.