13th Mar 2023, 21:50
The AGM battery in my Hyundai gave up after five years. Was quoted anywhere from $230 to $430 for a replacement. On a whim I called the service department at my Hyundai dealership and asked if I could use a regular battery. He said yes absolutely... so bought one for $150... and no problems. Don’t fall for the “you need an AGM only“ line.
3rd Mar 2026, 21:52
A 12V AGM is needed on electric vehicles which make intense use of the 12V battery - basically only the main electric motor is using the main li-ion battery.
Also, an AGM battery is important for vehicles equipped with automatic start-stop (engines stops and restarts when car is not moving) - these start-stop situations are also intense on the 12V battery, the reason why an AGM is needed.
For all other vehicles, you can replace the AGM with a regular, similar CAA acid-lead battery as long as the physical dimensions are similar and it can be secured by the locking piece and bolt.
My 2.4 GDI 2015 Sonata had a large AGM battery which died after 30,000 miles. I'm now running a regular acid-lead - it's actually smaller size so easier to replace when needed. No problems after 2 years in Canada - think very cold weather starts.
I do however suggest removing the AMS battery temperature sensor fuse, used for AGM batteries. AGM is charging at slightly higher voltage compared to acid-lead, removing the AMS sensor fuse may help having the acid-lead charging at slightly lower voltage - closer to voltages for acid-lead batteries.
13th Mar 2023, 13:22
True, they are still a little under par by some car's standards, but here in the UK you can get good deals on these cars and they are just about as capable as any similar mainstream manufacturer that is more popular. Hyundai and KIA have both improved quality a lot lately.