Servicing Your AGM Batteries

[Lug_Nut]

Those of us that have AGM batteries enjoy endless clean battery terminals. Whereas lead acid batteries scream for service by showing terminal build up. But, do AGM's also require clean up from time to time? Yes.

Though not as noticable, or even visible, oxidization does take place. This oxidization will eventually reduce the electrical flow. It can be seen by reading the amp inflow while charging and inturn displays less battery delivery while boondocking.

The oxidizing causes false readbacks to the charger causing it to think the batteries are fully charged when in fact they are not.

When you remove the terminals you will see they are not shiney clean. Using sand paper, clean each terminal both on the cable and on the battery post screw. After cleaning and reinstalling them apply a good protecter spray. When you finish, recheck your charging voltage. It will probably be much higher. Mine was at 13.5 top voltage rate before cleaning. After it displayed 14.5+. This should probably be done once a year.

So, if your coach just does not seem to hold voltage as long as it used to when dry camping, maybe a terminal cleaning may be in order.

Peter

[BryanL]

Good advice and suggestion to take care of batteries!

but re: "Those of us that have" -- trying to install a sense of umbrage?

Those of use that have proper charging and maintenance equipment and take care of our batteries don't suffer corroded connections, excessive electrolyte loss, or significant maintenance requirements - even with wet cell batteries.

re: "if your coach just does not seem to hold voltage as long as it used to when dry camping" -- need to be careful on just what you mean here. Poor connections tend to cause short term drops with load that recover quickly. Age tends to express as less ability to handle large loads where voltage drops in use and doesn't recover very fast.

As electrical connections are a major cause of RV fires, it is good practice to not only maintain the battery terminal connections but also those in the fuse block and at appliances. Tighten any screws and look for indications that the connection might have become heated at some point.

[Ramets]

I just had oxidation on one of my three AGM's. It was on the + post. I cleaned with baking soda, wire brush, and emery paper. It's the first time I've seen that. I'm keeping a close eye on it now.

[Lug_Nut]

Quote:

Originally Posted by BryanL Good advice and suggestion to take care of batteries! but re: "Those of us that have" -- trying to install a sense of umbrage? Those of use that have proper charging and maintenance equipment and take care of our batteries don't suffer corroded connections, excessive electrolyte loss, or significant maintenance requirements - even with wet cell batteries. re: "if your coach just does not seem to hold voltage as long as it used to when dry camping" -- need to be careful on just what you mean here. Poor connections tend to cause short term drops with load that recover quickly. Age tends to express as less ability to handle large loads where voltage drops in use and doesn't recover very fast. As electrical connections are a major cause of RV fires, it is good practice to not only maintain the battery terminal connections but also those in the fuse block and at appliances. Tighten any screws and look for indications that the connection might have become heated at some point.

"but re: "Those of us that have" -- trying to install a sense of umbrage?"

Hardly! My reason for this reference is particularly directed at AGM users. I had wet cells in my coach when new. I never had any problems looking after wet batteries in previous coaches which I did every couple of months. Those coaches were not "All Electric). My current unit is an "All Electric". The corrosion was unbeleivable. Never mind every couple of months, more like weekly, whether you use the coach or not. Anybody can change their batteries to AGM, it does not require a certain status of life.

My point here was directed at AGM users and the lack of visual cue as to the need to service.

Peter

[Norm4015]

I have used the same set of AGM batteries the last 10 years in two different motorhomes. When I installed them in my present motorhome in 2005 I cleaned the terminals and cables good and coated them with di-electric grease. Once a year I hose them off and I check the torque of the nuts. I'll put it on my list of things to do and pull the cables off and clean and inspect them. Sure won't hurt anything since they haven't been touched in 6 1/2 years.

[Ronnie Bledsoe 2006 Dutchstar 43']

Peter thanks for the post...I check the batteries often, but have never cleaned the terminals as no visible build up. SO I will add this to my maintenace schedule.

["007"]

Quote:

Originally Posted by Lug_Nut Those of us that have AGM batteries enjoy endless clean battery terminals. Whereas lead acid batteries scream for service by showing terminal build up. But, do AGM's also require clean up from time to time? Yes. Though not as noticable, or even visible, oxidization does take place. This oxidization will eventually reduce the electrical flow. It can be seen by reading the amp inflow while charging and inturn displays less battery delivery while boondocking. The oxidizing causes false readbacks to the charger causing it to think the batteries are fully charged when in fact they are not. When you remove the terminals you will see they are not shiney clean. Using sand paper, clean each terminal both on the cable and on the battery post screw. After cleaning and reinstalling them apply a good protecter spray. When you finish, recheck your charging voltage. It will probably be much higher. Mine was at 13.5 top voltage rate before cleaning. After it displayed 14.5+. This should probably be done once a year. So, if your coach just does not seem to hold voltage as long as it used to when dry camping, maybe a terminal cleaning may be in order. Peter

Thanks Peter I haven't check my batteries since putting them in three years ago, didn't realize the down turn in output until the other day, now I know why.

[Iron Man]

Thanks Peter for reminding those with AGM's to look at the once in a while to make sure they are still there.

[LindyT]

Thanks, Peter - haven't really given the AGMs a second thought, but probably should!

[Norm4015]

Over the weekend I checked the cables and terminals on my AGM batteries and there was no corrosion on any of them. When I installed them 6 1/2 years ago I cleaned everything good, torqued them with a torque wrench, and covered the terminals and cables with di-electric grease. They look just like the day I installed them. Once a year I put my torque wrench to the terminals and ocassionally one terminal will tighten maybe 1/64th of a turn. I will keep the AGM maintenance on my annual inspection list.