How to tell if cordless batteries are C or sub-C?

I've only ever seen Sub-C in a power tool.

Is that the old U2 size..?

Though beware of different lengths and diameters of sub-C

No, U2/SP2/HP2 are "D" sized

So there's "sub-c" and "sub-c" as it were?!

I'm some of the way to getting the battery case open, it's glued together so I'm slowly cutting through the joins with a knife. I guess I'll have to measure the cells and trust the seller (any recommendations?) to tell me the size of their cells correctly.

I was going to say that! :-)

Yes. Only way to be sure is to measure what you've got.

The only way is to measure their dimensions as accurately as you can.

Sometimes the plastic case will physically take full size C cells even if it was fitted with sub C. Strikes me as the battery equivalent of shrinkflation since you cannot see from outside what size they fitted.

I have seen sub-C with a ~2mm thick sticky tape on their circumference to make up the difference. I expect they are smaller *and* cheaper...

No.

C cells were different - more U11 IIRC

Size of pack vs voltage derived? I mean you can get more sub cs in than Cs. However I came unstuck some years ago with a Sony Ni Cad pack for a cassette recorder, it seemed to hardly have much life at all, That was because the flashy housing was D sized but the batteries inside were C sized due to the battery charging and monitoring circuit. Much better when you simply remote charged D cells and changed them when they were going down!

Brian

Sub C is a shorter length of C in my experience. One also has to beware of Alas hidden inside C cases and the same with cs inside D cases.

Brian

Most are shorter e.g 1/2, 2/3 or 4/5 length; but some are longer e.g 5/4 or 4/3 length, but are called "sub" because of reduced diameter

Utter crap. Sub C has an *exactly* defined meaning. An *exactly* defined size. "Sub C batteries look like a small version of a Standard C size cell. They measure 23mm in diameter by 43mm in length. " End of.

So a company like Panasonic wouldn't make a 4/5 length sub-C then?

No

That is not a sub C. It even says so at the top.

I am not arguing what sizes of batteries people make. I am stating what the industry standard Sub C size is.

Sub C, rightly or wrongly, because a specific size and was the most commonly sold NiCd/NiMh cell for power use.

I think the 2/3AA was the next most common