Gray "foam" in battery cells

Tulumtam

I was troubleshooting a system that was shutting down every day around 10:00 am. I took the cap off one battery cell to check the water level and discovered a gray foam-looking substance in the battery cell. All of the batteries have this to a greater or lesser extent. Any ideas about what this might be and what causes it?

Tulumtam

Re: Gray "foam" in battery cells

These are Trojan L16H flooded lead acid batteries. To provide just a bit more information….

Blackcherry04

Re: Gray "foam" in battery cells

What is the Make and Model of the Batteries ?? Are the batteries showing low capacity ?? Where I have seen it has been in a HD extra capacity batteries where the plates were pure lead. Once they sulfate the plates will begin to shed that dark gray oily stuff ( Lead Peroxide). Usually It's caused by high current charging or Prolonged Equalization. if you withdraw some electrolyte it will be murky until it settles out into the sump.

Blackcherry04

Re: Gray "foam" in battery cells

I missed your post about the make of the batteries, had a phone call before I posted. They won't be pure lead, but the same applies. Sulfuric Acid is oily and will allow the shedding to float when separated from the water. The foaming would have a lot of hydrogen and oxygen trapped in it from gassing. You'll see the foam on the underside of the cap and on the well sides from time to time. I'd look at absorb current and voltage and see if they are what you expected them to be and the SG levels.

If you have low SG's and they are sulfated then, the clean portions of the plates are shedding in excess because of the current. A good long slow low current EQ will correct that.