Highfields Amateur Radio Club
Glossary Appendix.
copyright date

Battery Details.

The differences between LR and SR cells:

LR cells are Alkaline Manganese based and have a lower energy density or capacity and are 1.5volts.
SR cells are Silver Oxide based, have a higher energy density or capacity and are 1.55volts.
See the Notes page for more info.

Do not confuse with these other batteries listed as "52":
CR1225 (Lith-52), 339 (52), LR44 (RW52), LR59 (280-52).

A Mercury free replacement for the once popular MR52 and equivalents. These Alkaline cells produce 1.5 volts, which is higher than the 1.35 volts produced by the original Mercury cell. Most devices accommodate the small increase in voltage and function perfectly adaptor

If you need an exact voltage replacement for the MR52 you could consider either the MR-52 Zinc Air cell adaptor (right) withadaptor an MRB675 or the Silver Oxide 392 cell, MR44 and MR52 Adaptor combination (left in conjunction with right), all from the Small Battery Company. Possibly the better solution is the 2 adaptors and the 392. The MR-44 Adapter has the outer dimensions of the MR44 Mercury cell with a recess that takes the inexpensive and easily obtained Silver Oxide 392 cell. Within the MR-44 Adapter are micro electronics that drop the voltage from the 1.55 volts put out by the Silver Oxide cell to the 1.35 volts that your equipment was designed for. This combination then slips into the MR-52 adaptor.
Why did I say "Possibly the better solution?" Well Silver Oxide cells are readily available, cheaper than Zinc Air cells and last longer too.

Equivalents:

23-1515, 640, 960-0374, 1105M, 1125M, 1126A, 1126MP, A640, A640PX, CNB-EPX640, CNB-RM640R, E140, EL40, E640, E640N, EN640A, EPX640, EPX640A, H-N, KX640, LR52, MR52, NR52, PC640A, PX640, PX640A, PX640AB, RM640, RM640R, RPX640, V640, V640PX,

Image
not to scale.
Common
Name.
Dimensions.
Diameter × Thickness.
Chemical Composition. Nominal Voltage.
battery PX640. 16 mm × 11.2 mm

Contacts:
Case and flat base Positive.
Raised area Negative.

Alkaline, 1.5 volts.

1.35 volts
(for the discontinued Mercury types)

Button & Coin Equivalents page.
Consumer Equivalents page.