How to charge the batteries without switching off the robot?

seregus · August 17, 2012, 9:12am

Hi all!

I got “6.0 Volt Ni-MH 2800mAh Battery Pack” to drive servos and motor controller, but very quickly discovered, it’s annoying to switch off the robot, unplug the battery pack cable and connect it to charger, wait and connect it back (during development process it’s very common situation).
Quick Google/Forum search didn’t bring me any answer (maybe I’m bad at this, sorry in advance), so my idea is to put something in between the robot and batterypack with the connector to connect the charging unit at any time, so it will charge the batteries and robot will continue to work during this.

Any ideas?

Thank you very much in advance for any cool ideas and suggestions!

permafrost · August 17, 2012, 10:01am

well, that depends on how does the batter plug look like is it like this one “http://www.lynxmotion.com/p-65-battery-quick-connect-mates-to-battery.aspx” or like a servo cable ?

and im not sure if its healthy for the battery to charge it while its running.

seregus · August 17, 2012, 11:00pm

Yes you absolutely right - this is how the batteries are connected to the motor controller… as for health of the batteries… your phone is working during the charging process, as well as all other devices, so it should be okay…

permafrost · August 17, 2012, 11:24pm

So far i haven’t seen a Y-connection for that cable so you might have to hand-make that.

innerbreed · August 17, 2012, 11:31pm

First most phone battery’s are Li-ion not Ni-MH for a start.
Second you might say "well laptops. Humm, well we all know that over time we all eventually end up plugged in as constant charging will deplete the life of a battery.

Then there is Ni-MH vs constant power and consumption at the same time…
not sure it will do your battery’s any good. you could however have one battery in use while you charge another?
and just have to put up with changing them over.

my fear is that even if you was able to keep the robot constantly powered im sure at some point you’ll burn out a servo motor. they need a rest too.

To actually answer you question… Yes it can be done, but your play time will end sooner than one would hope.

permafrost · August 18, 2012, 12:01am

Plus you will risk damaging the circuit board as the charger applies more voltage than the battery that may exceed the voltage limit the circuit can hold.

seregus · August 20, 2012, 10:15pm

Well, I already ordered PowerMatt and waiting for some connectors to arrive, so I’ll keep you posted if I was successful charging iCruiser.

Also I’ve ordered Anker Astro3, because of it’s 9-12V output and 2 USB ports and it’s size with 10000mAh gives me hope… PowerMat will not work with it, but at least it will be much smaller battery then I have now for LynxMotion AWD and also it will power up Raspberry and Motor controller as well.

Will check if I can somehow use PowerMatt to charge this one as well, the idea is about making a robot in Roomba style, so it can find his dock station come over and charge, instead of human to be involved in stopping, switching it off and charging, because it makes me fill - it’s not a robot.

seregus · August 28, 2012, 11:51pm

Hi all,

I’m not sure anyone is interested, but I promised to post an update.

So making it simple, yes, you can power up your robot with “Anker Astro 3”, instead of using strange batteries which will requeire you to switch off everything and unplug everything for charging. This battery is used as:

First USB output I’ve soldered to add 5V power to Adafruit module
Second USB output is used to power up Raspberry + WebCam + WiFi dongle
12V output is used to power UP DC motors.

So finally it’s a kind of Linux based (Raspberry PI) Internet (WiFi) controlled robot (my router is already setup to be accessible, through VPN, from outside world)!

I’m planing to add some Gyro/Distance sensors after it’s fully functional base (hope this weekend), if someone is interested, follow me up on my blog:
seregus.wordpress.com