Battery Fluid Levels

[Rainman4820]

I know this has been covered a zillion times but sometimes too much info is confusing. I have 6 month old batteries (6 6 volts in a 1991 Marathon) and check them monthly having only minimal water loss at this point.

While checking them today with a really good light and a wooden measuring stick, I noticed that there is about 2 inches of space between the top of the plates and the bottom of the fill hole. The water level has been about halfway between the two, or about 1 inch above the plates. I have read where the water level should be 1/4 inch below the lowest spot on the fill hole. I reaiize the plates should be covered to prevent issues but just trying to figure out by how much.

So the question is should I fill to just below the lowest part of the fill tube as most suggest or is 1 inch above the plates good enough?
Any help is greatly appreciated.
Rain

[DIRTPIT HC]

I am curious as to what brand batteries you have. I have never measured the distance from the plates to the bottom of the fill tube but looking I would say it's about one inch. I have interstate 8v batteries. I fill mine to 1/4" below fill tube as I figured that was easier to judge.

[Rainman4820]

My batteries are Duracell Ultra 6 volt ......SLIGC110 model number.

https://www.batteriesplus.com/batter...ic/na/sligc110

[Volt_Ampere]

As long as plates are covered you are in good shape for levels. Normally you want to fill them only after a full charge because the level rises during charging. I would start checking more often than monthly as they will eventually start using more water as they age.

[DIRTPIT HC]

Volt, is 2" a common distance between plates and fill tube? Just trying to learn something.

[Rainman4820]

Originally Posted by Volt_Ampere

As long as plates are covered you are in good shape for levels. Normally you want to fill them only after a full charge because the level rises during charging. I would start checking more often than monthly as they will eventually start using more water as they age.

Ok thanks, will do.

And on the 2" question, this may be something unique to Duracells. This time I gave them a full charge and filled to about 1/4 inch below the bottom of the fill well just to see if it makes any difference.

[skipsmith521]

I had wondered the same thing.

It seems the main objective is to keep the water above the plates.

Bringing the water just under the fill tube seems easier to see as pointed out.

I think the other objective is not to over fill so the water runs out during charging. This leads to corrosion around the battery tops and also the battery tray.

Trying to learn something as well.


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[JohnnieB]

Trojan's Plus Series batteries have a "Max" level ring at the bottom of the vent well as seen in first attachment.

The max fill level for their standard series batteries is 1/4" below the bottom of the vent well as seen in the second attachment.

For other make/model batteries that do not have a Max level mark of some kind, the information in the third attachment should be followed.

[skipsmith521]

This is the best message I have seen on battery water levels....The photos help.


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[JohnnieB]

The drawing (attachment-3) is from an EZGO TXT service manual (Battery and Charging section) and drawings with similar info can be found in Medalist and RXV service manuals as well as the service manuals for many other models.

The distance between the top of the plates and the bottom of the vent well is going to vary with the make and model of battery.

In general terms, lower storage capacity battery tend to have more space between plate tops and vent well bottom. The reason for this is because they are packaged in the same sized box, except the highest capacity batteries, which are taller with the same footprint.

Higher AH batteries have more lead in them, and the plate thickness and distance between plates have to stay pretty much the same, so to get more lead into them, the plates have to be taller, and wider if possible.

For example: US Battery has 4 grades of 6V cart batteries, from 208AH to 242AH and all have the same L/W/H dimensions. They also have a 251AH 6V cart battery, but its case is 0.625" taller, so we'll exclude it.

US 1800XC - 6V - 208AH - 39lb Lead - 6.97qt Electrolyte
US 2000XC - 6V - 216AH - 41lb Lead - 6.70qt Electrolyte
US 2200XC - 6V - 232AH - 44lb Lead - 6.50qt Electrolyte
US 125XC -- 6V - 242AH - 48lb Lead - 6.44qt Electrolyte

I got the weight of the Lead and volume of Electrolyte by model number from US Battery engineering, so they ought to be factual.

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If you routinely drive your cart on rough surfaces and/or steep hills, it is advisable to leave more room between bottom of vent and the electrolyte level, but always fill to at least 1/2" above plates.