Should this be worrying me? The battery is just 9 months old.

enter image description here

  • 1
    Are those covers removable so that you can check the fluid levels?
    – HandyHowie
    Jun 29 '20 at 7:49
  • Let me check if they are removable. Thought they claim its maintenance free :( Jun 29 '20 at 8:26
  • I believe the maintenance free just means that you shouldn’t need to top them up, but you may still be able to check them.
    – HandyHowie
    Jun 29 '20 at 9:11

It looks to me as the battery has been boiled, meaning the alternator overcharged it. This has several implications:

  1. If the alternator overcharged it, then it will do so again. If this is the case, you need to have the alternator tested to ensure the internal regulator is fully functioning. Overcharging is as bad (or worse) than undercharging. You can do a quick check using a digital multimeter. The voltage should not be above ~15vdc (normal range is usually ~13-14.2vdc).
  2. If it has been boiled, your battery could be low on electrolyte, which will shorten the useful life of the battery. While this is a "maintenance free battery", you should be able to pop the caps off and see if the electrolyte is up to the bottom (at a minimum) of the rings. If not, put some distilled water to bring it up to level. If the electrolyte is low, the "eye" may not be functioning correctly, either (charge level indicator in the top of the battery).
  3. If it has been boiled, there will most likely be acid in the battery tray, which over time will eat through the paint and metal. To counteract this, you'd neutralize the acid using some baking soda, flushing the area, then a final wash/rinse. Just using water on it won't completely remove the acid, so it's important to neutralize it first.

I agree with Solar Mike on the other part, which is to clean the top of the battery and applying grease to the posts to prevent corrosion.


Looks like the green eye is leaking a tiny amount of electrolyte and the liquid layer on the battery collects dust. (Those green indicators are almost pointless, but they probably sell the batteries better.)

The leak is minor and probably won't affect the battery performance.

It is, however, probably enough to cause accelerated corrosion of the battery terminals or nearby sheet metal.

Depending on where you live, you may (or may not) be able to ask for a replacement under warranty.

Update: Why I think so

  1. The wet area and the yellowish dust buildup both have a rough radial symmetry centered at the eye.

  2. When the battery boils, it either boils together with all cells (when in more or less sane state, Faraday's law helps), or boils the cell that is under the positive terminal first (when subjected to mechanical stress, because the positive plates are mechanically weaker and are first to lose the active mass). Here, the opposite cells have wet caps.

  3. A boiling battery usually has corroded positive terminal, clamp or wires with white or colored crystalline buildup. Negative is less prone to corrosion. But both terminals look good.


All looks very dry.

Remove, clean and put some grease or petroleum jelly on the terminals.

Otherwise looks very dusty.

  • I cleaned it. Lets see if in few days acid is visible again. Thanks Jun 29 '20 at 8:27

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