My Batteries now have Mineral Oil

[RJay]

The coach batteries are 4 Interstate Workhorse U2200 6 volt batteries. Before adding the mineral oil, I used a hydrometer to test the specific gravity of each cell and found all cells reading good to boarding line good. Since I was to be adding 4 oz. of mineral oil to each cell, I used the hydrometer to remove about 5 oz. of electrolite. I then added the mineral oil and topped off the cell with the electrolite I removed.

The battery compartment is in the rear of the coach and somewhat open to the engine compartment, I'm hoping by adding the mineral oil it will reduce or eliminate the corrosive effects of the gassing batteries, time will tell.

[lonestarace]

Mineral oil in lead acid batteries? I've never heard of such a thing? Would you educate us?
Thanks

[SCVJeff]

4oz per cell? Whats the recommended thickness of that layer?

[Elkhartjim]

I just replaced my chassis batteries a couple weeks ago and the owner of the Interstate Battery distributorship told me the number one cause of premature battery failure is that users are putting mineral oil in their batteries. I don't know, that's just what he told me.

And I would really question removing 4 oz of electrolyte and replacing that with mineral oil. After all, how many ounces are in each cell?

[GaryKD]

Hi lonestarace,
This comes under the topic of "sometimes it works and sometimes it doesn't". An once or two of mineral oil in flooded batteries does help reduce the out gassing and corrosion in the battery tray. One can debate this, but when I had flooded batteries it did work. If you do a search of iRV2 using "mineral oil" you'll see many discussions on this topic.

[RJay]

Sure, During the charging process gas bubbles are formed in the electrolyte. The greater the charge the more the electrolyte bubbles, you may have noticed them if your batteries were charging when you happened to be checking the electrolyte level in your batteries.

The bubbles are sulfuric acid gas that escapes thru the vent caps of the battery and settles on top of the battery, terminals, cables, hold down straps and the battery tray and is highly corrosive. The mineral oil sits on top of the electrolyte and holds the gas below the oil and can be recombined with the electrolyte preventing the gas from reaching the tops of the battery and everything else in the area. The oil also prevents water evaporation from the electrolyte and extends the time between watering.

Mineral oil is an electrical insulator and has been used by electrical manufacturers in distribution transformers since PCB's were banned forty years ago. Since a small quantity of oil is used there is still enough electrolyte between the plates and the oil so the specific gravity of the electrolyte can still be checked. If you happen to suck up some oil in the hydrometer by mistake simply put it back into the cell and continue checking the other cells and check that one last, it will give the oil a chance to settle out so you can get an accurate reading.

Since my battery compartment is larger, has a battery slideout tray and is in close proximity to the engine compartment, the damage caused by the corrosion will be much more extensive and very expensive to repair if left unchecked. I used 48 oz. of mineral oil to treat my four 6 volt batteries. At a cost of $1.58 for a 16 oz. bottle at Wal-mart I think it is a very inexpensive measure to take considering the alternative.

[JManatee]

I used Mineral Oil in my batts on my last coach. Never had a problem with the batteries.

I have wanted to do it to the new coach, but because I have a good 3 stage charger and solar charger my batteries dont boil very much and I have been lazy.

[Elkhartjim]

I can't wait to see where this thread goes. Wonder why the battery manufacturers don't just put a dab of mineral oil in each cell? Maybe and just maybe, it causes them to fail prematurely.

I am also curious about all the expensive damage that the battery off gassing is going to cause, My batteries sit on a fiberglass tray. I keep the cables and terminals clean and protected. Should I be protecting that big ole Cummins from something?

[Vegasdan]

Why not just give any metal in that area a light coating of oil?

[MrMudstud]

Here’s the deal………

This procedure has been going on for years. IT WORKS. Oil and water don’t mix, period. When the plates are water wet, oil will not wet the plates. As the batteries are concerned, there is water and acid on the plates and nothing else. Mineral oil floats on top of the water/acid phase and it has 2 main purposes. 1st it keeps the water from evaporating into the air and 2nd it has a blanket of oil on top of the acid to keep the bubbles from popping and throwing the flumes and spray out on top of the batteries. As the bubble leaves the acid and enters the mineral oil, it leaves all the water/acid liquid behind and only the air bubble is in the oil. When the bubble leaves the oil and pops out into the air; (the oil is thicker and slows down the time of travel) it stays behind and no liquid (water/acid/oil) lands on top of the batteries or anywhere else. It is as simple at that.

Does it work? Well, I have been using it for 5 years and I still have the same 6 volt batteries on the house side of my coach. They still read as of yesterday of 12.6-12.7 volts when the charger is off. It works for me..............

[RJay]

Originally Posted by SCVJeff

4oz per cell? Whats the recommended thickness of that layer?

The thickness of the oil layer or the the amount of oil added to a cell depends on the type of battery. For a 6 volt deep cycle battery 4 oz. is normal.

[RJay]

Originally Posted by Elkhartjim

I just replaced my chassis batteries a couple weeks ago and the owner of the Interstate Battery distributorship told me the number one cause of premature battery failure is that users are putting mineral oil in their batteries. I don't know, that's just what he told me.

This may be true because those who tried it added too much mineral oil to the battery. But remember, these people are in business to make money, do you really think they will tell you a way to prolong the life of their product where they will lose sales?

Originally Posted by Elkhartjim

And I would really question removing 4 oz of electrolyte and replacing that with mineral oil. After all, how many ounces are in each cell?

The space above the battery plates is like a reservoir to allow for a variation in water level without harming the battery. The golden rule is that you don't let the electrolyte go below to top of the battery plates. So removing some of the electrolyte will do no harm. But more importantly it's not the quantity of the electrolyte but it's quality. Electrolyte is 35% sulfuric acid and 65% distilled water. When you test the specific gravity of a battery cell you are actually measuring the amount of sulfuric acid left in your battery. It's the sulfuric acid that causes the chemical reaction and consequently the electron flow between the battery plates and the terminal posts. So what is important here is that there is enough electrolyte below the oil to the top of the plates to allow the electrolyte to be tested.

[Bob (WA0MQE)]

If you want something that works good, try these. Water Miser Battery Caps

They really do work. I put them on my four new Trojan T105's back in 2005 and they have never corroded. Likewise the water does not spew out when charging. You will still need to add water from time to time, but not nearly as often.

[deandec]

Another Mineral Oil convert.

Trojans are well beyond their 60 month warranty and working like new.

So any future failure surely will not be premature.......