AGM, or Absorbed Glass Matt batteries are finding their way into more and more cars on the road. Once found mainly in high performance cars, your everyday driver might just have one under the hood. These batteries don’t have the traditional spillage problems and perform better because the electrolytes aren’t in a liquid form, but are held in a suspension. This keeps is in constant contact with the lead and means better efficiency when discharging as well as charging. Usually. Sometimes, if the battery is discharged too much, it might not take a charge anymore (at least not without a little help)
This doesn’t necessarily mean that your battery is toast. If you have another battery that’s well charged (12.4 volts or more), just connect it in parallel with the dead AGM battery on your charger. Use a set of jumper cables and connect the good battery to the AGM battery, + to +, – to -. Just limit your charging to 10 amperes, and save yourself from having to replace an expensive battery!