Remember to water your batteries

[CJ7ole]

I filled my two wet cell house batteries last summer. The starting battery is sealed. So I thought I better check them again, and after 8 months, it took almost a third of a gallon of distilled water to fill the two batteries. Must be due to always being on a charging system. The rig did get 4 months of use during that time period, so a lot of charging was going on. Fortunately, all of the cells still had water over the top of the plates. Anyone have one of those automatic battery fill systems? Might be worthwhile.

[dennis45]

There is a LOT of discussion on this subject. My solution was to add 4oz of mineral oil to each cell. My rig is in use or plugged in at all times. In 18 months I have not added water and my compartment stays clean with no corrosion of the terminals. Sorry for the upside down pic. Not sure why that happens.
Also, do check your battery voltage while plugged in to shore power. Should be Max 13.6 - 13.7 VDC. Higher voltage will result in boiling off the water.

[WrongWayRand]

It's a good idea to check monthly, and add just enough distilled water so that the level is just below (approx. 1/8th inch) the plastic inside the cells when the battery is fully charged. Letting them get that low can permanently damage the plates, which will reduce their capacity and longevity.

As for the automatic watering systems, I've not used them, but I know that they are very popular.

- Randy

[dennis45]

Originally Posted by WrongWayRand

It's a good idea to check monthly, and add just enough distilled water so that the level is just below (approx. 1/8th inch) the plastic inside the cells when the battery is fully charged. Letting them get that low can permanently damage the plates, which will reduce their capacity and longevity.

As for the automatic watering systems, I've not used them, but I know that they are very popular.

- Randy

Thanks for mentioning that. I do in fact check my batteries about every 6-8 weeks but since adding mineral oil, I have not had to add water at all and we are either on the road or plugged in during storage at all times.

[topdownman]

I added a watering system to my batteries. I read somewhere recently it was a bad idea to add mineral oil. Comments?

[dennis45]

Here is one of the threads on the subject of mineral oil if your interested. The very last post is interesting.

http://www.irv2.com/forums/f258/mineral-oil-177333.html

[scenic route]

Originally Posted by topdownman

I added a watering system to my batteries. I read somewhere recently it was a bad idea to add mineral oil. Comments?

It's been done for decades. I had corrosion problems in our battery compartment...cleaned, neutralized and painted, twice. Last time, I put 4oz of ThermOil in each cell(after I fully charge and checked each cell with a hydrometer). That was 4 years ago with no corrosion since. Our house batts are 10 years old. When they give up the ghost, I'm going to do the same with the new ones.

BTW, I went with ThermOil because someone recommended it. If you operate in warmer climes, I would think that regular mineral oil would work just as well without the extra expense. As I understand it, ThermOil has a lower freezing point.

[KSCRUDE]

Originally Posted by scenic route

It's been done for decades. I had corrosion problems in our battery compartment...cleaned, neutralized and painted, twice. Last time, I put 4oz of ThermOil in each cell(after I fully charge and checked each cell with a hydrometer). That was 4 years ago with no corrosion since. Our house batts are 10 years old. When they give up the ghost, I'm going to do the same with the new ones.

BTW, I went with ThermOil because someone recommended it. If you operate in warmer climes, I would think that regular mineral oil would work just as well without the extra expense. As I understand it, ThermOil has a lower freezing point.

No oil will freeze. Different oils have different specific gravity's, and poor points, but it never freezes. Mineral oil works great for this application.

[KSCRUDE]

Originally Posted by topdownman

I added a watering system to my batteries. I read somewhere recently it was a bad idea to add mineral oil. Comments?

Not a bad idea, but a good idea. Most watering systems are junk. Mineral oil is fool proof if administered correctly.

[DavisK]

Mineral oil freezes between -10° to -30° F. Sulfuric acid freezes at -77° F when a battery is fully charged.

[djbmsu]

Mineral Oil in RV's since 1985 and I have never purchased a battery.

[dennis45]

Originally Posted by DavisK

Mineral oil freezes between -10° to -30° F. Sulfuric acid freezes at -77° F when a battery is fully charged.

There is no chance me and my coach will see -77 F, alive anyway.

[H. Miller]

Originally Posted by KSCRUDE

Not a bad idea, but a good idea. Most watering systems are junk. Mineral oil is fool proof if administered correctly.

JUNK! We own 3 ProFill systems and all work as advertised. The MH has no moving tray so sticking ones head 3' into a dark hole to check water isn't going to happen nearly often enough (every quarter at a minimum)

[CJ7ole]

I had totally forgotten about the mineral oil thread. Thanks for the reminder. Read the whole thread so I guess I am off to the store to get some MO.