We've tested and reviewed products since 1936. Read CR's review of the Super Start Platinum AGM 51R-51RPLT car battery to find out if it's worth it.

We've tested and reviewed products since 1936. Read CR's review of the Duralast Platinum AGM 51R-AGM car battery to find out if it's worth it.

In Group 51R (more Audis, BMWs, Hyundais, and Mercedes-Benzes), the Super Start Platinum AGM 51R-51RPLT was tops. Battery life and cold-weather performance earned excellent ratings while reserve ...

All battery packs are li-ion fireball capable. If it's charging then it means the Polarity is correct. Otherwise you'd not get the little charge light.