The Robot light is blinking slow red which means the backup battery is dead. We’ve replaced the batterys on the backup battery twice and it still blinks red slowly. we’ve disconnected the competition cord and it turns green so we know its the backup battery. For the live of us we can’t figure out whats wrong. Has anyone run into the same issue?
Joe,
I haven’t used the backup battery yet, I will plug it in tonight when I get home to see what I get. Is your main battery > 7.5 volts?
Yes it reads 10.1 volts
Dude,
The Cortex controller system is new to me and OCCRA, so we may not be able to answer your question.
I plugged my backup battery, measured 9.0 volts in the on-line window and the Robot light was green. So, mine worked, but that doesn’t help you much.
Did you confirm the voltage measurement in the On-line window? Reason, purely speculative, is that if there is a problem with the Cortex system measuring the backup battery voltage, even though it is “good”, it will be red and you might be able to confirm that by reading it inside of EasyC V4.
Of course, it is possible that your system is faulty. I will not be there tomorrow ,but, next Thursday I may be able to test your system at the OCCRA competition event number 2.
You might be able to show your system to another team at tomorrow’s competition and get some answers from another team.
Some more info,
Talked to Mike Martus and played some more with Cortex system with backup battery and found the following:
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With backup battery, Cortex remains powered for 3 minutes with Robot LED flashing red, after turning off.
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Turning Cortex back on, with backup battery, with Robot LED already red
with not turn to green without turning off the joystick controller as well. -
So, with backup battery, when Cortex unit is turned off, joystick controller must also be turned off and both turned back on to get rid of flashing red Robot LED on both units.
Hope this helps,
It seems as though the backup battery is completely useless for the big robots. Here is why:
You already have a separate battery to run the controller off of. The main purpose of the backup battery is to run the controller when the main battery temporarily (not for extended periods of time) dips below normal, such as when many motors stall and the battery is beginning to die. It is designed for normal vex robots, which pull all of their power from that little 7.2v 2000mAh (or 3000mAh) battery. Running only the controller, it should never do this. In this case, you are now powering your robot with 3 batteries, the main battery, the controller battery (just so it isn’t affected by main battery low-ness), and a backup battery for what is essentially a backup battery.
You could alternatively connect the cortex to the 12v main battery. In this case, your main battery would have to dip below around 6.5v for the cortex to become unhappy. If your main battery is that low, it is probably very dead and under very heavy load. However, we lived this way for a really long time (using the IFI control system without its backup battery) without issues, so I don’t think this should cause worry.
For the vex robots, the backup battery becomes more necessary. But, the old PIC processor lived without it just fine. (Although it didn’t have a link process to run, it just kept waiting for data and processing it, and could boot in under a second)
Side note:
If your main battery is a vex battery (as in the “main for the cortex” battery, not main robot battery, or if this is a vex robot), then it should never get to be 10.2 volts. It is 7.2v nominal, so 8v is probably around its maximum. You could be using the 9.6v battery for the old joysticks (its wider but more flat, and says 9.6v on it), and that is not good.
If you have connected your cortex to your main big robot battery, then 10.2v is very very very dead and should be charged.
Some truth to what you say regarding the big robots. The 7.2 if fully charged will last 4 matches…HOWEVER
This past week several robots lost the CORTEX function as the 7.2 battery failed. If they would have had the 9V in place the robot would have played the match.
Also the lack of the 9v gives you a annoying red light! This causes the field set-up to have to stop, look and verify that the red light is for the back-up and not something else.
We will have a decision by the G&K that this 9v is required at inspection. It is easy to install and causes no issues.