not to scale.
Name.
Length × Diameter.
Contacts: Mini snap connectors either end (making battery longer).
(650 mAh).
Contacts: "Pips" either end.
OR
Flat Base Positive
"Pip" Negative.
(650 mAh).
Don't confuse this 523 with the 30 volt 523.
Some sources list the IEC 3LR50 as one of these two, slightly different batteries, other sources list it as the other:
One of them has flat pads at opposite ends for the connection (I have also seen this listed as 3LR51), the other uses small snaps, 1 at either end.
I think the confusion arises because they are both out of general production but are made by smaller companies using 3 × LR50 cells. Possibly one is the closest that that particular company gets to the other, Look at the details and decide which is the best fitment for your equipment.
Equivalents:
523: (flat ends)
3LR50, 3LR51, 3MR50, 333, 333CZ, 523, 1304, 1306A, 1306AP, 1314M, A133, A21PX, APX21, E133, E133N, EN133A, EPX21, H-3P, PC133A, PX21, RPX21, T133, T133M, TR133R, V21PX, V21PX2, VS-149,
531: (snap connectors)
531, 1307AP, 3LR50, A19PX, EPX19, PX19, RPX19, V19PX,
| Image not to scale. | Common Name. | Dimensions. Length × Diameter. | Chemical Composition. | Nominal Voltage. |
|---|---|---|---|---|
|
| 531. | 58.3 mm × 16.8 mm Contacts: Mini snap connectors either end (making battery longer). | Alkaline replacement. | 4.5 volts (650 mAh). |
|
| 523. | 49.9 mm × 16.8 mm Contacts: "Pips" either end. | Alkaline replacement. | 4.5 volts (650 mAh). |