APC Back-UPS battery

[PlainName]

EDIT2: I guess you meant price for 2 batteries since you compared it with RBC113

Yep (and don't forget to add shipping - £6 from there)

Thanks for the recommend re Yuasa. I've used them previously but only in non-UPS kit (alarms and bikes).

[james_s]

Why would there need to be the shape of the caps in the top cover? I mean, if it's a separate cover, surely just a flat thing is perfectly OK and less tricky to make (although the indents wouldn't need to be accurate, of course).

Also, batteries I know have the fillers all in a row. I've never seen a car battery or bike battery with them in two rows, so a quick look at these without knowing anything further would suggest there is actually 3 cells rather than 6 (the two circular marks being for terminals, perhaps).

However, thanks for enlightening me. I can feel the urge to dig out some YouTube stuff...

You'd have to ask the engineers who designed it, I don't know why they chose to do it the way they did, I just know what they look like. There are different layouts but the typical 12V SLA that's about the size of a brick has three groups of two side by side cells wired in a U shape from one terminal down one side from cell to cell, across at the other end and back up to the other terminal giving six cells in series. The caps are in the same layout, each one has a rubber vent valve/cap over a tubular stem that sticks up and then the cover is glued over the top otherwise those rubber caps would pop off instead of acting as a one-way vent. As I said, they're either six individual little round covers, or a single large rectangular panel. Either one is easy to pop off using a knife, putty blade or small screwdriver. There's no liquid sloshing in these things and the dead ones are usually bone dry so go ahead and pry the lid off one of the old ones and take a look. If you pull off the rubber caps you can peer down inside with a flashlight and see the top of the plates.

[james_s]

As the saying goes, a picture is worth a thousand words. This is a small Power Sonic 12V SLA that was in my battery recycle box. This one is the inline configuration where all six cells are in a straight line as opposed to the style common in small UPS's that is a bit like one of these folded in half with both terminals at the same end. This is also the type with a single flat panel over the valve caps instead of individual caps over each one.

[PlainName]

Thanks