Advice on new RV battery maintenance.

Grit dog
Missed your post but yes solenoid and transfer seem to operate just fine. Batteries are performing for now. Water, cleanup and a couple of charges seemed to work wonders. For now. The acid is a bit low in a few of the cells but the indicator still floats.
I charged them together then separately. I have a good variable Vector charger that was recommended here a decade ago. It was worth the $$.

Just in case anyone wonders whether their good advice is heeded. I just finished cleaning up the batteries and battery box and treated with Harbor Freight spray on undercoating. I’ll use these batteries first trip out as the seem to be taking a charge and holding it. Two 62 AH batteries are all that fit in the tiny battery box or I could go with one 100 AH. The box is 12” x 18” at its widest. My plastic box in the 2003 Itasca is larger. The paint was chipped but there was negligible rust so I just brushed it and cleaned it with baking soda water and sprayed it. Still took me several days.


Looking at lithium’s I could fit 3 80AH or 4 36AH (considerably cheaper! But would need a DC to DC charger. Won’t justify the expense for awhile. Maybe I should look at lithium capable converter/chargers first.

I've used POR-15 to treat rust where my tractor battery puked all over. It's expensive too but works great and leaves a nice black color so paint isn't even needed. Years later it still looks like new.

POR-15 SDS

Thanks for the recommendations for new hardware. I was beginning to think that was the best idea. That and a baking soda wash for the compartment. And the Bed liner treatment is a great hint. Sure appreciate the expertise.

Gdetrailer wrote:

I DID mention that, however, phosphoric acid in Ospho is "enhanced" with some other ingredients that are not present in other "rust converters".

Apologies, when you said:

Ospho and Navel Jelly are two different products with no real common ingredient that I can find in the SDS for both..

I read it to mean that they had different primary ingredients (both are primarily phosphoric acid).

FWC wrote:
Just an FYI, orthophospheric acid is exactly the same thing as phosphoric acid which is the main ingredient in most 'rust converters' which form an iron phosphate layer, aka 'Parkerizing'.

I DID mention that, however, phosphoric acid in Ospho is "enhanced" with some other ingredients that are not present in other "rust converters".

As I mentioned, Rust-Oleum USED to sell just plain "rust converter" all by it's self, it DID work OK.

However, that standalone version was discontinued quite a few yrs ago and they came out with a combination "rust converter/primer/paint". That combination version is not as effective, bordering on barely works and worst yet, it comes out of the can flat black already..

You don't really know if the combination version is even working..

Far better to SEE the conversion process alone, it can take 24 hrs or more depending on temps and humidity for the process to finish.. Once the rust has been converted it is a simple mater of priming and finish paints.

Keep in mind the OP mentioned using Navel jelly to convert the rust, it is not the correct product if you want the job done right the first time.

But for the OPs battery hold downs, if you don't wish to spend the money on Ospho, then by new generic hold downs and hardware and discard the old ones.



Found HERE for $14 each and you get all new hardware.

You can also get plastic hold downs if you dig around.

I would however recommend if you do buy new steel hold downs, treat them with at least two coats of Harbor Freight bedliner.. That stuff is a tough rubberized paint that should hold up well to acid fumes.

The batteries came with the coach. I didn’t ask how old as I assumed I’d have to replace them. I was surprised they took a charge so well. Have had the coach plugged in since I got it so don’t know how much life they have but they started the generator while it was in storage when I bought the unit.
We have snow again today so I’m holding off on the battery job and playing with inside mods while making space for our camping stuff. There is so much more space in this RV over our 22e. It’s amazing.
I’ve been using sealed batteries in our old RV that don’t require filling.

I have found that when I overfill the battery cells with water I get that kind of corrosion. Also excessive charging, like when a battery is starting to die will do the same. How old are your batteries? Load test to see if they are still good if you think they don't hold a charge well. I would just clean the tops of your batteries, the dirt/stuff on top can cause the batteries to self discharge faster, remove the rust with a wire wheel and paint the metal with black paint, rustoleum, fill cells enough to cover the plates don't overfill and see if you still get that kind of corrosion. I don't use grease or any other stuff and don't see that corrosion since I stopped overfilling my battery cells.

I purchased 20 gallons from Spectrum Chemical in Reno in 1979. It left a Batyleship Gray coating. Treated battery trays. Then sprayed zinc chromate. Finished with Body Shootz undercoating which is a bedliner.

Just an FYI, orthophospheric acid is exactly the same thing as phosphoric acid which is the main ingredient in most 'rust converters' which form an iron phosphate layer, aka 'Parkerizing'.