Strange corrosion around battery tie down

[dnhxx]

I have some corrosion building up around my nylon battery tie downs on our Bay Star. We have 4 6V flooded golf cart batteries. We are fulltimers and have had those batteries for 2.5 years and have never seen corrosion around the strap. I don't see any corrosion on the battery terminals. I use a pro fill battery watering system and check once or twice a month, and also check the batteries with hydrometer once a month. Normally we are moving every 10 days or so, but we have been in the same campground now for 2 months, and it is very humid here (PA). I plan on pulling everything out, cleaning, and then apply POR-15 which I saw another thread. Why and how are the straps getting corrosion on them?

[Spk64]

May have had a boil over or spill at some point.
I clean my batteries and tray annually and use some baking soda to neutralize any acid. Even leave a little dry in bottom.
On year 3 and no signs of corrosion anywhere.

[twinboat]

Open the caps and see if the profill is overfilling a cell or two.

[Dutch Star Don]

Clean the acid with baking soda or a battery spray and then coat the metal to protect it. You can use something like "below" to protect it.

I'm not sure what inverter/charger your coach came with, but if it's a Magnum, you may want to get the battery brand and amp hour info and give Magnum a call. They'll walk you through the set up of your inverter/charger and make sure all the charging rates are correct, which is often the cause of battery acid issues.

[alank]

You didn't show the tops of the batteries, but my guess is that acid is on the tops of the plastic battery cases and is wicking down the plastic strap fabric, then starts to show up when it hits metal.
Put the straps in soda too.

[dnhxx]

to follow up what I have found.
There was no corrosion on the terminals, but a little bit of the white corrosion scattered on the edges of the battery. We have the OEM battery converter, progressive dynamics charge wizard.

I pulled the batteries out, and looked at the water level in each cell. None looked low or high. I reconnected the pro fill and filled with water, and then rechecked. All looked good. What I did find, is the swivel tee on the Pro fill was very hard to snap on several cells. When the batteries are in the tray, I have limited access to the back two batteries, so I believe that I did not have the tees on tight enough. I was told by Flow-Rite that this could allow some of the acid to escape. They are sending me new tees because the ones in question take excessive force to snap on.

The tray was not too badly corroded, just a few spots, but I can't put the POR-15 on yet because it is too humid here right now.

thanks for the responses