Battery Corrosion

I check my batteries regularly, but was surprised to find the amount of corrosion that appeared since I last looked at them.  One of the positive leads was heavily corroded and the negative had some corrosion.  But, what surprised me the most was the fabric strap and metal securing attachments.  The hooks at the pan, both sides were very badly corroded.  The spring loaded tightener was even worse.  The teeth on the tightener were caked with corrosion.  It will need replacing as it is too hard to adequately clean it.  On the corroded leads, there was electrical tape over the swedged area of the terminal.  I removed the tape and found the corrosion had gone under the tape.  Can not see how the corrosion occurred on the fabric strap terminals as there was no corrosion in the area or on the pan they were attached to.  It was like the strap acted like a dissimilar metal to the metal end.  Of course that is not possible unless there is some metal filaments embedded in the strap.  What was strange was the battery stud and securing nut where the corroded lead was attached had no corrosion. 
     We picked up the coach in December of 2010.  Have made two short trips and it has been stored at home since.  I regularly check the battery status, but do not keep electricity on the coach unless we are getting ready to leave.  I run the generator at least once a month to keep the carb clean and that provides enough charge to the batteries.  So it is hard to see what generated this amount of corrosion. 
     I will pull all the leads off the batteries and do corrosion prevention and likewise the strap fittings.  This is just info where you all may want to check your batteries.
    Bob   

I purchased a battery cleaner and then applied a sealer on all the post. Another tip is to keep-um as clean as you can. Wipe of the crude on the top.

Billy,
    That is what was so confusing.  I keep the batteries clean and there was just a small amount of corrosion on two of the four terminals.  The major corrosion was on the metal strap ends where they attach to the tray, although the tray was corrosion free.  The worst corrosion was on the metal spring loaded tightener and it was not touching anything.  As the tightener is directly over the batteries, maybe it acquired corrosive acid by the outgassing of the battery vent.  Being a former aviation electrician I am always taking care to prevent corrosion.  I guess I had a mental lapse in not treating the posts and fittings when I first brought the coach home.  So, they are getting the full clean and treat procedure now.  So far have not been able to find a securing strap, so may need to order one from PC.
Bob

Bob,
Home Depot had at one time some of the narrow tie down nylon straps and they work well for replacements.  Just for info I have had NO corrosion anywhere since I went to the central/single point water fill setup talked about in another thread.

L. G.

I just cleaned the same corrosion from all the areas you described plus from the tray and both slides.  I, too, removed the tape from the cables and found corrosion.  Baking soda and water made the clean up easy--but very messy.

Our 2007 2350 had a serious battery corrosion problem, exactly as Bob has described above.  It turned out one of the two batteries was not taking the charge as well as it should.  The ill battery had the charging system over-charging the pair, trying to get to them to a full charge.  Of coarse it never could, hence battery over-boil.  I replaced both batteries and I have not had any corrsion problems since.  Those metal strap clasps, battery terminals, and battery tray stay in good condition now.

I didn't realize I had a battery problem because the on-board charger never indicated a problem, and the RV functioned well..  I think I had that problem form during our first 3 week trip, but didn't figure it out untill well past the warranty period.

I bought the largest deep cycle batteries that Walmart sells.  They fit perfectly snug in the battery tray which makes the Tripp-Lite inverter's sensor wire with square tip, well wedged in-between.  The Walmart batteries also have a well engineered top where if there is an over-boil, it doesn't make a mess.  At least not right away.

Bob, I advise to take out both batteries and put them on a smart charger, one at a time.  You may find the one battery won't take a full charge.  At least that was my story.  BTW: I think the straps wick the acid to the clasp and hooks.

I think Ron is absolutely right about the straps.  I wondered when I first read about the problems as to why they ever used any sort of cloth straps.  Once they get wet with water contaminated with acid or sulfate deposits, they become conductive and support oxidation.  Virtually every battery hold down strap that I've ever seen in the past has been made out of rubber. 

Jerry

Billy,
    That is what was so confusing.  I keep the batteries clean and there was just a small amount of corrosion on two of the four terminals.  The major corrosion was on the metal strap ends where they attach to the tray, although the tray was corrosion free.  The worst corrosion was on the metal spring loaded tightener and it was not touching anything.  As the tightener is directly over the batteries, maybe it acquired corrosive acid by the outgassing of the battery vent.  Being a former aviation electrician I am always taking care to prevent corrosion.  I guess I had a mental lapse in not treating the posts and fittings when I first brought the coach home.  So, they are getting the full clean and treat procedure now.  So far have not been able to find a securing strap, so may need to order one from PC.
Bob

Lead acid batteries will find a way to corrosion. They breath and that's a problem to corrosion.

To All,
    Good info.  I am now looking for a different type of battery tie down.  If I would go to a rubber strap, the tray would have to be drilled for the metal end. Most of the available securing devices have a rod at each side with a cross piece secured with nuts on the rods.  Do not enough clearance for this.  If anybody finds something that works let me know. 
    Bob

If or when I see this problem starting, I'll use long heavy duty plastic tie wraps in lieu of the strap.

If or when I see this problem starting, I'll use long heavy duty plastic tie wraps in lieu of the strap.

Now that is why forums survive - great ideas.