2023 MK Battery Failures

111/112 has been seeing an abnormally high failure rate on our 2023 batch MK Batteries while charging. Batteries were purchased mid-February, and we have had 5 of our 24 new batteries begin to leak from the top weld seams or terminal potting so far. We do not suspect that this is a result of contact damage in our battery trays.

Wondering how many other teams have been seeing this? I have heard from a few other teams with similar issues, but nothing stated in a public forum.


Are these the x variant or normal part number, i know issues with the x variant were identified early this year and apparently it means they are made in a new factory with a slightly different process


Non-X variant.


a bunch of our new ones failed their cold cranking amps, they have all had to be taken out of rotation

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We haven’t had an outside visual failures but had one of our new ones internally fail. Plugged it in in the pit, walked out to the field. Loaded onto the field before the match and turned the robot on. Read 12.4 volts. Before the match started it was down to 9 volts. Wont charge or hold a charge now. Had three matches on it. Always keep a spare on the cart now.


That’s just good advice in any case. We always keep a spare battery in the cart, even though we haven’t had any battery problems. It’s just part of the old engineer’s “belt and suspenders” approach.


This hyperlink was in line with the same issue. These MK batteries could not hold a charge nor would charge fully. In my mind I thought it originally was a faulty cell but I don’t think they were made to spec. We actually scrapped all the black batteries we purchased (8) and reverted back to https://www.andymark.com/products/mk-es17-12-12v-sla-battery-set-of-2?via=Z2lkOi8vYW5keW1hcmsvV29ya2FyZWE6Ok5hdmlnYXRpb246OlNlYXJjaFJlc3VsdHMvJTdCJTIyYnV0dG9uJTIyJTNBJTIyc2VhcmNoJTIyJTJDJTIycSUyMiUzQSUyMmJhdHRlcnklMjIlMkMlMjJ1dGY4JTIyJTNBJTIyJUUyJTlDJTkzJTIyJTdE

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Similar issues to us, we bought 16 new mk from Andymark at the beginning of the season. 5 failed our CBA testing, of the rest one failed us during competition with brownouts after 30 seconds. Unfortunately we we too late to get them tested for the return policy. Of the remaining 10 only two are close to our 4 and five old batteries in performance per cba testing. We have not had any leak yet.

Also had one of ours leak. Glad to know it’s not just us. Ordered mid Feb, direct from MK California.


We have also seen at least 1 battery leak, also purchased direct from MK in mid Feb.


Just as another datapoint, we bought 4 MK batteries this year, from 3 different suppliers.
Out of those, 1 passed our acceptance testing.
That one has since been rotated back out of service for re-testing since we saw early brownouts with it.

I am unsure if they are X variants or not, but we will definitely be doing more testing in the offseason to determine how we can get the most out of these batteries.

We’ve also lost 2 MKs this year to leaks in the top seams, plus one having the potting completely pop out when we tried to attach a lead.

Will grab the details on the batteries themselves when I’m in the shop tonight & will edit.

Anyone know of good alternatives? Interstates aren’t the greatest, is the next best thing a duracell?

In my own and others’ experience Duracells wind up around 5-10% better in capacity than MKs, but at almost 2x the cost (historically). I think it’s closer to $50 vs $70 these days.

We have been nothing but happy with our Duracells since we started using them in 2019, cost aside.


There is green stuff coming from the top seals of our MKs too, I’m not sure if its a leak but Ill edit with a photo around noon and hopefully someone can let me know.

Depends on the amount and color. If you’re seeing a small amount of something that’s yellow-green-clear IN the seam that’s likely the seal/glue holding that seam together. If there’s anything coming OUT of the seams that could be an issue.

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We had a large leak this last weekend with an MK battery purchased at their physical location in Anaheim no more than a month or two ago.

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Past teams I’ve been on used PowerSonic brand (PS-12180NB) and were happy with them.

Edited to add P/N


Link or p/n?

Are any vendors willing to do ship to pit orders for Houston for any brand other than MK?

@Andy_Baker @NathanNFM @Greg_Needel


We had one battery leak this year