What to do with old robot batteries

The autozone here will take them, but they won’t give you any money for them. In addition, the sealed batteries are exempt from the core refund law (like aluminum returnable cans) in most states.

They are excellent door stops.


We’ve got a toxic waste disposal center in our town that takes them off our hands.

That’s what we do with ours. Unfortunately, we picked early this year to swap out some of our old batteries, so hopefully we can get get a refund or something.

Robot batteries, dead or not, are incredibly useful as weights. I believe that that opens up a whole pile of oppurtunities.
Other than that, most car repair places or boat repair places should either take them or know where you should send them, as both cars and boats use lead-acid batteries in their engines or whatnot.
Course, you could always try demanding a refund from the company you bought the batteries from… Could be VERY interesting.

Not sure how far you would get with this, you would have to make a very strong case, and i’m not too sure what case you would even come up with.

We have a few scrap yards in town. They give us a couple bucks each if we bring the batteries to them to be recycled: http://ontariopricelist.scrapmetal.net/pricelist.php

If they’re completely unusable, as many have said you can recycle them.

If they’re a little usable, but not suited for competitive robotics, when coupled with a power inverter they make great mobile power supplies for the stands (e.g. scouting computers, phones, etc)


We take them to our local EMR in Delaware along with aluminum scrap.

I have asked at some auto parts stores in Houston and they said they would accept them.

I take ours to Batteries Plus most of the time. Just call ahead and bring them in. Never worried about trying to get money for them.

We also try to give any that sort of work to rookie teams that may not have a stockpile, we label them as not for competition use but having extra batteries for demos is a luxury not every team has.


This is a neat idea, if you happen to have one of these still put together can I see what it looks like? I have a 2011 battery, and it seems to hold a charge well at 6 volts. It sounds like it could be able to be used for something like this. Thanks!

Please send batteries like this to the recycler. Quite a few of the cells are shorted. The charging current may cause the shorted cells to overheat and possibly explode.

The inverters also have a minimum input voltage and won’t turn on.


Ah, good to know… I still want to see this setup with the power inverter for other batteries we have. I’ve read people use the battery beak to measure the internal resistance. Perhaps this is a good way to sort out the batteries that are still usable, and the ones that really should go. I presume though… all batteries should be safe just as weights as long as they remain in room temperature environment.

Yes! A Battery Beak is a great investment for maintaining your batteries. Please note that a high internal resistance reading could be due to the battery cables not being tightly bolted to the battery terminals. If you can turn the battery cable lug with your fingers it is too loose.

The inverters are pretty simple. Use an old battery cable and connect it to the input terminals of the inverter. The packaging of the battery and inverter is where you can exercise your creativity to make it easy to use instead of a PITA to use.

The batteries are safe to use as weights as long as the case is not compromised in any way. Also, make sure they are fully discharged. The voltage is too low to hurt someone but if the battery still has significant charge, the current can really heat something up if the battery terminals get shorted together.


To connect an inverter, we just cut off the car 12v plug (cigarette plug) and crimp on an SB50. Just make sure you get positive and negative correct.


I don’t have a picture but it couldn’t be easier. Take a power inverter meant for automotive use, chop the cigarette lighter plug off, crimp the two wires for an SB50 Anderson connector, and you’re set. Be sure there’s a fuse in line somewhere (many inverters already have one).

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We have an SB50 connected to a cigarette receptacle. That way we don’t have to modify the inverters. Do make sure your used batteries get into the recycle stream rather than a land fill.

The two typical ways a battery goes bad: one is a cell short. The battery won’t charge to 12V (nominal) or quickly drops 1.5-2V when you try to use it. Two is sulfation. The battery capacity is diminished. With modern chargers there is very little danger of a catastrophic failure. The battery just becomes less and less useful. The desulfation cycle on some chargers actually seem to work. Sometimes. If the battery case is swollen or damaged, the battery has reached the end of its useful life and should be recycled.


Thanks everyone for the responses so far!.. I’ll discuss with team on these suggestions.

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