Identifying Battery Type: Standard Lead-Acid or AGM?

QuestionsCategory: Ask An ExpertIdentifying Battery Type: Standard Lead-Acid or AGM?
Robert Moore asked 5 months ago
I recently came across a battery in my car and I'm unsure whether it's a standard lead-acid battery or an AGM (Absorbed Glass Mat) type. I need to know this to choose the proper charging setting. What are the key differences and how can I tell them apart?
1 Answers
Zack Norman Staff answered 5 months ago
Hi there, Robert! Thanks for the question, it's a good one! Identifying whether a battery is a standard lead-acid or an AGM type is quite straightforward once you know what to look for, so here's what you need to do and look out for:
  1. Labeling: AGM batteries usually have "AGM" clearly stated on the label. Some brands may use different terminology; for example, BMW batteries might say "VRLA" and Fiat batteries "Heavy Duty".
  2. Part Number: In some cases, like Motorcraft batteries, "AGM" will be part of the part number.
  3. Physical Characteristics:
    • Caps: Standard lead-acid batteries often have removable caps for adding water. However, AGM batteries are sealed and do not have such caps.
    • Weight: AGM batteries are generally heavier than standard lead-acid batteries.
  4. Sound Test: If you gently shake the battery, a standard lead-acid battery may produce a sloshing sound due to the liquid inside. AGM batteries, being sealed, will not make this sound.
  5. Other Markings: Look for terms like "non-spillable" on the battery. Standard lead-acid batteries don't usually have special labeling.
Remember, these are general guidelines. There can be exceptions, so it's always a good idea to consult your vehicle's manual or a professional if you're unsure. For your battery, check for these indicators. If it's not explicitly labeled as AGM and has characteristics of a standard lead-acid battery (like removable caps), it's likely the latter. Hope this helps! Zack - Motor Verso Mechanics Team