3 times now within a year my check engine light comes on with at least 5 different codes. (random codes each of the 3 times) First the service center said it was the battery. That I wasn’t driving it enough to keep it charged. The 2nd time they replaced the serial data gateway module. This 3rd time they told me it was the battery again. They said the battery is fine it’s just not being charged. I drive my car in town at least every other day. I don’t know how they can say it isn’t charging. Research tells me I should start my car at least once a week to keep the battery charged so I’m baffled. I thought I would reach out to you for suggestions before I claimed the lemon law.
From personal experience with a NEW vehicle, the battery can test good but not be. I am assuming they replaced the battery at no charge if not you can replace it yourself. I had to replace my battery myself and it fixed my issues. (was on an older vehicle but still a similar issue) When the battery has an internal short it has trouble taking a charge.
A test you can perform would be to connect a battery maintainer on it when not driving and see. But I would ALMOST be willing to bet if you installed a NEW battery your issues would be resolved and should in no way void your warranty.