Can Magni’s be left Charging

Hello. We have not been running our Magni systems for about 3 weeks, so although the battery’s are not being discharged rapidly, we are worried that the lead acid batteries would become discharged past the recommended battery voltage after more time. we were wondering, to prevent this, would it be safe to leave the Magni’s charging for several weeks with the provided charger? Would the chargers stop automatically once a certain battery voltage is reached? If so, what is that maximum voltage that the battery charges are set to? Any information would be helpful. Thank you.

Hello. Yes these chargers sense the voltage and automatically cut off when the battery is fully charged. This happens typically around 28 volts. If the battery drops lower later the charger will turn back on and charge back up the battery.

It is therefore safe to keep the charger plugged into the Robot.

Several things have been done this year to add visibility into the battery voltage on the product but they apply only for when the robot is turned on.

  1. With our latest firmware that is still in ‘beta’ phase we have implemented some special blink codes on the MCB status led. Normally the status led does one ‘blink-out’ every 4 to 5 seconds. With the soon to be released v39 you would see every minute an unusual blinking pattern of one long blink of a second long followed by 3 short blinks then back to normal pattern for another minute. This is part of improved power on and continuing self test monitoring. FYI: That code is a Morse code ‘B’ for battery.

  2. Recently with version 5.2 MCB boards we have been shipping a small OLED display on the lower right of the MCB. Although not part of our standard upgrades yet we have posted on our OLED software part of our open source repository the software and how to enable showing the IP address and name of the robot as well as a continually showing battery voltage.
    refer to: https://github.com/UbiquityRobotics/oled_display_node

  3. Battery voltage will soon be shown every so often in the ROS log on a regular basis.

  4. we have always had battery voltage be broadcast on ROS topic of /battery_state

I realize this is a bit too much info but I post it for others who may be reading this thread as well as your information.

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Thank you Mark. This is not too much information. It was all very helpful and I’m glad you went into depth about the upcoming features relating to battery monitoring. I appreciate the help. Keep up the good work!

Ok, thanks for feedback. [oops removing comment for other thread]

If you have a rev 5.2 or later MCB many things get fixed but a very exciting one is the built in selftest.
I have not fully described it well yet but it is starting to be discussed at the end of this page (as well as the blink codes I mentioned):