Battery corrosion question

[Kirah]

So, I have neglected my poor Chinook the last 6 months and basically left it hooked up to a battery tender while I dealt with the rest of life. I went down this weekend to look things over and run it around, and found that the positive battery terminal had built up a pretty impressive mound of corrosion. The clamp for the battery tender was half gone (but apparently still charging, as the engine started at once).

I've gotten it pretty clean again, thanks to some time soaking in baking soda (paste on the terminal, and the lead in a cup of solution), but I'm not sure why it happened. I have clear memories of my grandfather pouring a bottle of Coke over his car battery as part of his routine maintenance, but I haven't seen this in decades. I guess I assumed modern batteries didn't do this any more. I've certainly let batteries sit for similar lengths of time without corrosion building up.

Is it a problem with the battery? Or something to do with the tender? Or was I just lucky before?

[chin_k]

It the battery acid that came up due to capillarity action, and corrode the metal post away. Some people use dielectric grease on the posts, and you can even buy pieces of felt and some solution that can help with that. If you have a voltmeter, you can probably touch two random spots on the top of the battery case and be able to see voltage flowing thru.

The coke thing I don't get it. Your grandfather probably was using the phosphoric acid in the soda to clean the plastic case. If the soda get inside, it is not going to be good. There are cheaper alternatives to clean the battery case (check out auto part stores), but you can't drink the cleaning solution when you have leftover.

I wonder if there anything that we can use beer to clean with???

[68camaro]

I am interested in why this happened also. I have had a battery tender on my Camaro 24/7 for years and years and never had this problem.

For my Chinook, I found the best way to keep battery charged was to charge before storing and putting a cut-off switch on battery terminal so I can stop parasitic drain.

[chin_k]

I think you should still go charge the battery every 3 months if there is no load on the terminals. It is because there is always some voltage leak. I don't think the battery tender contribute to the corrosion.

[ntxconcoursexl]

Have you done the Progressive Dynamics upgrade yet? It has 3 stages instead of blasting constant current to the batteries. I had a major issue with this on the old Magnatek system in my 2003 Concourse XL and after the swap it has not came back. Also they make a red battery coating for the terminals available at any auto parts store. When it fades to clear it is time to re-coat the terminals.

[chin_k]

I think 68camaro has the PD4645, among several others on the forum. I also have replace my converter from PD.

[markatherton]

Is there a reason not to ugrade to the PD4655 instead. It is just a slightly larger unit? Mark in San Diego

[chin_k]

If the wiring between the converter and the other end can handle the current, that is fine. ideally, you should also fuse the connection, but it is not done in the Chinook. you don't want the wiring to overheat or burn when it does send 55 amp of current to the batteries and overwhelm the wiring.

The PD4655 is slightly more expensive, and if the batteries and the appliance does not take advantage of the extra 10 amp of output, it is like wasting your money. For me, I do have the 4655, not because I purposely put it in there, but because I was able to get it on a good deal.

[Kirah]

FWIW, I cleaned everything up and got the kit from an auto parts store with grease and felt rings. Hooked everything back up and haven't had any more corrosion problems, even though it say another couple months on the tender before I was able to start using it regularly again.