Hi all,
I need to power my project with batteries, and the different modules needs different voltages:
arduino uno with wifi board 5v pulls ~ 160mA
servos 5v pulls ~ 800mA
amplifier 6...16v (i want to use as much voltage as i can, within limits..) ~ 300mA
radio receiver 3v pulls ~ 150mA
overall ~ 1600mA
These are my goals:
I want to be able to recharge it "like a laptop", so that it can run while it is charging (like it's in a docking station).
size and weight is important, should not be much bigger than a fist, not more than 1kg, as this will be a semi portable "robot".
safety is an issue, that is, I'd best avoid batteries that explode and such
one charge should last 2 hours at the least
What would be a good approach to this? Lipo? Nimh? Charger? A good way to regulate the voltage?
(I've looked a bit into lipo batteries, but I cant find any over 3.7v that have a protection circuit.. and the voltage seem to stop at 7.4v..)
thanks for any hints or suggestions!
how long?
I'd go with rechargeable battery pack & switching regulator to make 5V, small linear from there for 3.3V.
You can find higher voltage LiPos with charge control built in. I have one at home.
Here's one with a solar charger built in even:
Buy ALLPOWERS 23000mAh Solar Laptop Panel Charger Portable Charger Backup for Laptop, Tablet, iphone, ipad, Samsung, Blackberry, Digital Camera, Bluetooth Headset & All Other USB Compatible Devices: Solar Chargers - Amazon.com ✓ FREE DELIVERY...
There's a bunch of 14.8V packs here
http://www.all-battery.com/li-polyerbatterypacks.aspx
So the stuff is out there, you just need to look more.
The other option is a high capacity (mAH) 3.7V cell with boost regulators for the higher voltages:
Take a look at this one too. DC 12V Super Litium Battery There are all different sizes that can output from 1800mAh to 15000 mAh. They take about 6 hours to fully charge, but they can hold that charge for a very LONG time, even under constant uses.
CrossRoads:
how long?
hah, dont know how that disappeared.. 2 hours at least
Thanks for the suggestions! It's true, I'm not sure where to look.
Can I use all these batteries even when they are charging? And can they stay in the charger safely for a long time?
The one I suggested can be used while charging, but it will take longer to get to fully charged.
If you're drawing 1.6A and charging at the same time, the charger will need to be really overkill to support both.