Lead Acid Battery on it's side

Thread Starter


Joined Aug 29, 2008
I'm working on another UPS.
While topping off the water in the batteries, I thought of how these particular batteries must fit back in the UPS.

With this unit, the batteries go into the USP case sideways, so the water inside the cells will be perpindicular to what you would expect to see (such as a car battery)

Does this different orientation affect the life of the battery in any way?

I use super glue to put the plastic caps or covers back on.
That seems sufficient to prevent spilage.
Are there better ways to secure the caps / covers?



Joined Feb 5, 2010
Placing a flooded cell battery(added water) on its side, is BAD practice. Only gel cell and SLA are known for that ability.


Joined Mar 14, 2008
What type of cap/cover do these batteries have? If the batteries were intended to be laid on their side the caps should be designed for that and not have to be glued on.

Are you sure the batteries are intended to have water added and are not maintenance free types?


Joined May 11, 2009
I do not think it would do any harm. To just do this for the short period it takes to put it in place. As long as it is sealed. Sealed Lead acid batteries was used in scuba diving flashlights at least around 1998 I remember. And that was before gel type time. In a car the battery will never not be leveled all the time.

Thread Starter


Joined Aug 29, 2008
They are small 6" long, 3" high, 2" wide, batteries like you would find in a scooter, or UPS, etc.

They come with either a flat plastic cover, or individuial covers the size of a quarter.
Underneath the caps or cover, the cells each have a small rubber boot, or cap, which you have to remove to see inside the cells.

I fill each cell with distilled water, up to the bottom of the neck for each cell, reinstall the rubber boot, the super glue the plastic cap or cover back on.

Its called a sealed maintenance free rechargable battery, but I've salvaged many of them over the years.

My concern is with this one, which has the battery basically laying on its side.
I don't want battery acid to leak out.

Does anyone with prior experiences have a better idea than Super Glue?
Is this practice a bad one?

I'll just let the glue dry, then turn it on its side in a safe place, and observe.
I will also reassemble the entire UPS, set it upright, and plug it in, and observe for any leakage.



Joined Mar 24, 2008
Placing a flooded cell battery(added water) on its side, is BAD practice. Only gel cell and SLA are known for that ability.
Which is what UPSes use. I have never seen a UPS use anything different, the battery is surrounded by hot electronics.

Thought about using lead acid batteries for homemade UPSes outside though. Never done it.


Joined Jul 17, 2007
Well, most batteries in UPS's nowadays are the sealed AGM type; where AGM = absorbent glass matt. If you added water to them, you would weaken the electrolyte strength, and risk spillage. AGMs are designed to have a minimum amount of electrolyte in the matt between the plates. That way, they won't leak electrolyte if the case ruptures.


Joined Sep 24, 2007
Laying them on there side are OK, if they came out that way they must be designed for it.

If the caps were glued in place to begin with you should glue them back on, what works for black plastic battery case is the glue in the hardware store that is used for black sewer pipe, the black glue melts into the plastic it touches to make a permanent bond. There are other methods also like using the soldering gun to melt the two plastics together.

I'm thinking most batteries have a vent for if or when the battery is overcharged it will vent rather than split the case, so inspect the case and make sure you are not defeating the vent place.

Water is what you should add to the battery but make sure you leave room for the water/acid to expand. The rule is, you can fill the battery to the full point if the battery is fully charged, but only cover the plates if the battery dose not have a full charge, then charge the battery and finish topping off.