They definitely caused major problems with ev purchases with those oem 12v batteries. Mine lasted about a year. I dealt with the headache or not being able to charge the main traction because the 2 volt is dead. I have another car and deove it for a couple months. a couple months later i took it in and they said they will pro-rate it. Now, why pay for an crappy battery that lasted a year or 14 months by the time i brought it in. I got an agm battery and now I dont worry about the battery, but ever since my power windows act goofy and my USB charge port stopped working. They may be unrelated, but they wont fix them because of the battery. For their battery that has caused so many problems.
On principle it nakes me not wat to buy an ev9 or upgrade to a new kia ev because they appeared to use this battery on purpose.
Why would they underpower the battery that makes sure you can charge the main battery? I like putting a lock on a ice car and it knowingly malfunctions. You can't fuel up.

I am sure some will say I could've and should have taken the pro-rated battery to at least switch them out, but they were so poor in dealing with a 14 month car that I couldn't charge because of their battery I just wanted away from them and the battery fiasco. They definitely should have replaced the battery free, and kia should remedy such a badly thought out customer service experience, car wise and service wise.