V1 - Brain error "Replace Robot Battery" with fully charged battery packs

VEXIQ V1 Brain shows the error “Replace Robot Battery”, red light is on. Battery is fully charged. Tried different battery packs with the same error.

Any suggestions to a fix / things to look at? (I’ve never seen this error)

There’s a “Replace Brain Battery” error when battery is at low voltage (<6V) and you try to run a program. What does voltage show in system info ?


The battery icon shows full charge. I didn’t think to look at the system display. It’s at the school, so I’ll need to check that in the morning. We are just trying the stock driver control.

Checked this morning all the battery packs were at 8 volts, but they were fresh off the charger from last night. So it’s possible they were down. The packs are also 5 years old at this point, so there may be some bad cells.

I’m going to mark this closed with a note to put the battery packs on the charges again. Thanks James for your help.


So glad I found this thread. I was going crazy trying to figure out why almost all my teams had brains that seemed to be dying at the same time. I am on the same boat, all these brains are about 4 years old.

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Mark, you might want to wait on replacing battery packs. The new V2 packs are compatible with the V1 brains, but you do need new chargers. No sense in buying back into an ecosystem that is being discontinued. We should see individual battery packs for sale across the summer.