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Replacing Batteries
Back in 2009 I removed the gel Dominator batteries that Liberty had installed because I had one that had vented and replaced all 6 8Ds with Lifelines.Well 5 years have passed and Tom had additional factory discount from Lifeline so I ordered 6 8Ds because my batteries would only run 1 Cruiseair during the night for about 2 hours before the generatort would start.Today I pulled out the TV and audio system out of the bay and the panelsTo gain access to the batteries I was surprised to find corrosion on 2 of the negative terminals on 2 of the old batteries,I am sure that it had a effect on performance.I want to eliminate this in the future so I purchased 6 sets of new marine battery terminals.My question is what else should I do to eliminate the corrosion in the future.
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39 Replies
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Corrosion only happens when the batteries are leaking. I saw the same thing on my Lifelines and was able to seal up the leak at the terminal with some Goop or similar product (sorry, don’t remember what I used). Lifelines are great, but they are not perfect. If you are seeing what you are seeing, the battery is leaking when it should not be.
Now, if I am reading your post correctly, there must have been some time period with your Lifelines where you could run a Cruisair for more than 2 hours while dry camping. Could you give us some details here? I can’t imagine ever being able to run a Cruisair on batteries at all much less for more than 2 hours.
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With 6 8D batteries 1 cruise air would run about 6-7 hours at night.The caculation I use is 255 amps X 6 batteries = 1530 X 50% draw down =765 divided by(120 volts divided by 12 volts=10)=76.5 amps avaliable divided by cruise air amp load 11 =6.95 hours.The caculation does not include the efficency of the inverters or the time that the cruise air is not running or other electrical loads like refigeration.I was surprised to see the corrosion on the terminals,when I get the batteries out I will inspect them and try to find the leak.Because Liberty uses Cruiseairs that blow hot air under the coach and the Generator also blows the radiator discharge under the bus The batteries take a lot of heat during the summer dry camping,also the batteries are fitted in a very tight area that has limited ventilation.
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Jack,
I’ll run that by Lifeline on Monday and report back to you. I think I know the answer, but would rather be accruate.
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Tom,I looked again today and there are 4 with corrosion on the negative terminals,but they do not have any on the positive terminals.One of the batteries had corrosion almost the size of a golf ball,I should have taken a picture but I used a vaccum cleaner to remove the ball.
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Yes corrosion is typical if you have a gasing battery. It could also be due to environment, like salty air from near ocean camping. Why only the negative terminals? It could be proximity to the vents.
What you’re brought to light is the need for periodic inspection and maintenance. It’s too bad some installations make periodic maintenance a PITA.
After you install the new batteries you should consider spraying the terminals with a corrosion preventative.
Good move using marine grade cables; they are different. The stranded copper is tinned to help fight corrosion.
While you’re there make sure the batteries are wired to take full advantage of the batteries. I use a positive and negative buss bar with each battery directly connected to the buss bar. This is typical in yachts, but not coaches. You will want to make sure the positive and negative main cables are connected to opposite ends of the bank. You will also want to make sure the temperatue sensors are both on the same battery.
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I really can’t rewire as the inverter bay is on the drivers side which would require me to remove all 6 batteries,2 Cruiseairs,battery frame work etc,I am able to install the new batteries and wiring just like Liberty did.This coach has Outback inverters and the 2 of them comminucate with each other so there is only 1 temperature probe but it does adjust the charge of both chargers.I will use some of the anti corrosion spray,is there anything else that I could do to prevent this from happening again?The time that it takes to remove the entertainment and pannels makes it almost impossible to perform maintence on a regular basis.I had 1 cruise air out a year or so ago but that only let me inspect 2 batteries and they were in good shape.If these have vented I think that it is a result of the heat that is discharged under the bus,I have a remote thermometer in the inverter bay and I have seen 145 degrees (which will shut down the Allen Bradley computer)in that bay so I now open the bay when I see 115-120,even though there are 2 fans in that bay they are picking up hot air from below the coach.
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Thanks Jack, I’ll get you feedback from the experts tomorrow.
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145 degrees is HOT! The inverters are rated for 50C or 122F. At 50C their power is derated. If you get these temps more than rare occsssions you might want to force some cool air into that bay. At that temperature even if the electronics are working their life will be shortened.
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Tom,
What kind of feedback are you looking for? The Lifeline batteries do leak (cracks in the casing) with time. I spoke with Lifeline and they confirmed this only wanting to know how old my batteries were (still under warranty?). You could see the crack right at the base of the terminal and while I worked for awhile to keep the corrosion away with cleaners and sealers, using some kind of a very thin “Goop” was the only thing that once again sealed the battery to prevent the gasses from corroding the connections.
I am not saying anything bad about the AGM batteries as I absolutely love them and would own nothing else, I am just relating the realities. This coach has wet cells when I bought it and they were complete disasters! Cheap? You bet! Needing constant monitoring and replacement and destroying the battery storage compartment with the gasses? You bet!
I will never have anything other than AGM for house batteries there is no need for AGM for starting batteries. Those I buy at Sam’s Club every 4-5 years and I doubt an AGM would do any better.
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The reason I have AGM for starting batteries is to have the same charging characteristics as the house AGM batteries. Since I can only set the inverter/chargers for either flooded cell or AGM1 or AGM2, it makes sense to me to keep all the batteries the same type.
Of course this only is a factor when parked and the inverters are maintaining the chassis batteries in addition to the house battery banks.
Maybe you have a different system that maintains the chassis batteries?
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I can see where that would make a big difference. My coach has has nothing that will charge by 24V starting battery bank. If I am going to sit somewhere for 2 weeks I have to plug the chassis batteries into a separate charger. Otherwise, they are only charged when the engine is running.
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Jack: My Allen Bradley/inverter compartment fan draws outside air into the compartment through the door and exhausts it into the center a/c/battery/compressor compartment which, of course, is open. I’m surprised you’re seeing temps quite that high if your vent fan(s) are working unless you’re in extremely high ambient temps or you are correct that your fan pulls air in from the battery compt. If that’s the case, there has probably been an error in the fan installation/wiring.
As I recall, my original fan was 115 volt which ran all the time. I replaced it with a 24 volt fan and thermostat which causes the fan to operate only above about 85-90F.
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Jack,In
talking with Justin at Lifeline, there are several possibilities.He
said the way the terminals are built into the battery and then
covered makes it very unusual for any leakage, but it has happened.
The leakage usually shows quickly, but since yours are buried like
mine, it’s hard to inspect them.Another
problem is stress on the terminals by pulling with the cables, not an
issue here because Liberty does a good job with sizing and cable
runs. If heat is the problem, he said all batteries would be
affected, not just one or a few.145
degree’s is hot, no doubt about that and could contribute to leakage.
Like Joel, I put new fans in and went to a thermostat rather than the
fans running 24/7 and failing.The
terminals on the 8DL’s are a shiny copper like a penny. He said if
heat is the issue, the terminals tend to turn a black/blue in color.I
wanted to get you information direct from the factory and no doubt
others will have their own opinions, but at least you have the
benefit of knowing their thoughts on the corrosion and possible
reasons. -
I doubt that 145F batt temp is a problem directly although cooler is better. I bet the chassis batts get to 145 regularly here in the southwest with the engine running. I would be concerned about the inverters operating in that environment.
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Joel,Liberty added a additional fan that discharges into the center of the coach this was added under warranty after I complained that the bay temperature shut down the Allen Bradley Computer,the other fan discharges at the edge of the bay.I think that Liberty did a bad job of venting the inverter bay and both of the fans are mounted low in the bay,I have ducted 1 of them to pull air from the upper area at the rear of the bay and that seems to help.The other problem is that all of the replacement air is from the under side of the coach which on a hot day is very hot from the AC discharge and the generator radiator.The bay got to 145 several years ago before I installed a remote thermometer,I can now monitor the temperature and open the bay to cool it.When the coach was less than 1 year old I had a gel battery vent and I now think that the battery rack is just not vented well enough,I think that I will put a remote thermometer sensor on top of the batteries and see just how hot the batteries get.I am thinking that I have the space to add a fan that would pull air from the 2nd bay and cool the battery area.What temperature does the brain trust think is safe for the batteries?
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