The 2022 Hyundai Elantra Hybrid Blue intermittently displays Check Hybrid System Stop Safety in instrument cluster screen, which stops the car from driving in either smart or normal. This happens on the roads and highways. This is very unsafe because at high speed when this happens you could easily get rear-ended because the car drops its speed and cannot accelerate any faster than 30 miles per hour and then it degrades to 20 miles per hour until I can find a safe place to park and turn off the car to do the reset to be able to drive again. This happens because the 12-volt lithium battery is not providing an acceptable amount of charge to the hybrid battery. This was also confirmed when I took the battery to get tested and it failed the test.The next part that is unsafe, is replacing the low 12-volt lithium battery, because it is connected to a high voltage 240-volt lithium-ion polymer battery; there a normal person cannot simply replace it. You have to know electronics to make sure you do not get electrocuted. In addition, it takes hours to take out the battery and then itas hard to find to purchase. I feel Hyundai makes this process difficult as after spending hours to screw it out, you cannot locate the item anywhere. When I spoke to the Hyundai parts person, they could not locate it until I actually brought in the battery. The 12-volt lithium battery was nonrefundable and cost twice as much ($545.92) as I saw online, as low as $282 once I obtain the part number from the Hyundai order, which again is nonrefundable. I feel they make sure this cannot be found to force you to come to them to buy the battery, because all the labels or characters on the battery were not able to locatable. This was proven by me emailing the battery images to the parts person who was trying to find it, but could not until I bring in the actual battery. I was also told it is a special order and that they do not keep them onsite and have to be ordered and wait 7 to 10 days(pdf attach)