VEX batteries are hard to insert/remove


Hi, I’m a new VEX IQ user in my classroom and have a classroom set of these robots. I noticed that the batteries are super difficult to insert and remove on a few of the robots. I’m not sure if it’s the battery that is causing the issue or if it is the individual robot… more testing is needed. I understand that you don’t want the battery to come loose super easily, but one robot and battery combo, I had to get a hammer to tap the battery out of the robot brain. Any suggestions on how to improve this?



New to me, we have dozens of IQ brains. Never had a problem except when someone puts the battery in backwards. They are sometimes a bit firm, in that you have to depress the locking clip pretty hard and push it out from the other side.



I take it the brain is still connected to the robot in these cases? Is it possible the structure itself is obstructing the battery or rubbing on it? Or is the battery not going in square? I’d recommend pulling the brain off and trying the fit first, so you know if it’s a battery/brain compatibility issue or something else. I suspect the students didn’t have the battery aligned properly when they inserted it.

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No, the brain was just loose. This was me doing this… not my students. I stuck a battery in to power the brain to make sure that it and the remote were paired before I turned the kits over to the students to start building. I had easy access to be able to put the battery in and remove since the rest of the robot body wasn’t even built yet. I had the clip pressed down, but the battery still wouldn’t budge just using my hands. I’m fairly sure the battery went in square since there was nothing there to obstruct it, but I guess it’s always possible that it didn’t.



@mcarr I got four sets of robots that had this problem. If you look at the sides of the battery there is a tenon that holds the battery in place. This is actually the seam of the top/bottom of the battery.

On mine the seam was noticeable. Because of the tight tolerances that makes VEX work, the battery won’t slide into the brain.

My fix was to take hook knife and slide it down the tenon to remove some of the plastic. It was a scrape and test process, but it didn’t take long to get them to fit.



Also, just like the Smart Cables, push in before you press the tab down while removing, otherwise you can bend the tab (batteries) or wear/break the catch (cables).

Once bent, battery key is the only way. Look for white stress marks on battery tab. I put students through pointed, exact training on this, they still mess up…



We’ve had similar issues since the beginning. We have the kids use a large bladed standard screwdriver in a manner similar to the “key” above. They insert the screwdriver over the tab, rotate slightly, and push from the back of the brain. Works every time, The tabs on the batteries deform very easily.



Thanks for the suggestions, everyone. I didn’t have a knife, but I did have some sand paper so used that to remove a little bit from the tabs on the sides of the batteries as I needed to. I just had to make sure to clean them off well after. @rhowbot thanks for the tip about the battery key. I’ll keep that in mind, if I continue to have problems.



Our kids find it easier to push it through from the other side rather than pulling it out.