Hi,
I am making a project where I need to power 3 stepper motors(using a4988 drivers) and an arduino off a battery supply. My batteries are 7.4V lithium ion and I have two of them. I would like to power the arduino off 7.4 and the drivers off 14.8V. I had attached a basic circuit diagram to show what I want to do and was just wondering if this would work or is the best way of doing this. Thankyou
It's not ideal using a tap from one of a series battery pair because obviously the bottom one will discharge faster. But provided the Nano has nothing else connected to it so it's drawing very little current and also you recharge each of the two batteries separately when needed you should get away with it.
I'd probably power the Arduino from a 5V DC-DC converter from the 14.8V. They're tiny and cheap.
Steve
Thanks for that Steve, didn't know they existed, will use one of them
Thanks
eBay LM2596 adjustable buck modules are cheap and seem to work well in my experience (refreshing for eBay!)
Unbalancing a series string of battery cells isn't a great idea for battery life, although if the
battery uses a balancing charger and the tap takes only a small proportion of the current its
not going to be too bad, as the rebalancing will repair the imbalance each time.