Which battery replaces the PX825?

The PX825 is a 1.5-volt alkaline manganese button cell (Zn/MnO₂), made from the late 1960s onwards by Mallory, Eveready, Varta and Kodak, mainly to power simple light meters, flashcube firing and electronic shutters in compact and Instamatic cameras. Despite the “PX” prefix, which people often associate with mercury cells such as the PX625, the PX825 was an alkaline cell from the very start. Dimensions: 23.2 × 6.1 mm. Common cross-references: V825PX (Varta), LR53 (IEC), EPX825 (Eveready), KA825 (Kodak), NEDA 1129AP.

The PX825 was used mainly in Kodak’s Instamatic series: Kodak Instamatic 124, 154, 174, 204, 224, 304, 314, 404, 500, 704, 714, 800, 814, Instamatic Reflex and S10/S20. On top of those come models from other makers, such as the Minox B4 and C4, Voigtländer Vitessa 1000SR, Zeiss Ikon Voigtländer Prontor 500 electronic, Vitessa 500 AE/SE, GAF 100 XF / 102A / 200 XF / Anscomatic, Argus 254/264/364 Instant Load, Hanimex IC 2000 and Agfa Agfamatic 126. Many of these cameras take two PX825s in series (3 V total). You’ll find the full, searchable list of 43 camera models at the top of this page.

Original PX825s have been practically out of production since the early 1990s. They were discontinued for commercial reasons: demand for 23.2 mm button cells for vintage Instamatic cameras simply became too small, and the physical format makes no economic sense next to today’s much smaller standard alkaline and silver oxide cells. To put this in context: the PX825 was an alkaline cell from the start, so the EU mercury bans (Battery Directive 2006/66/EC, Battery Regulation 2023/1542) don’t apply to it. Either way, replacements are easy to get today, both as same-size drop-in reproductions (e.g. the Exell S825PX in silver oxide, also sold as LR53/BLR53/KA825) and via adapters.

There’s no single “best” replacement; three options are common:

• Exell S825PX (silver oxide, 1.55 V). The direct drop-in: A reproduction with an identical form factor and the original 23.2 × 6.1 mm dimensions. No adapter needed, just pop it in. Silver oxide delivers a steady voltage over almost the entire discharge curve. Available from specialist retailers such as mdbattery or smallbattery.company.org.uk. Also sold under the designations LR53, BLR53 and KA825.
• Adapter with two small 1.5 V cells (the Ausgeknipst solution): A plastic adapter fills the large PX825 compartment and holds two modern LR43/LR54 or silver oxide SR43/SR54 cells, wired in parallel to deliver the nominal 1.5 V. The upside: standard cells you can buy anywhere, long life and an exact voltage match to the original alkaline PX825. Available from Ausgeknipst as the PX825 two-cell adapter.
• LR44/SR44 with a spacer ring: A single LR44 (alkaline, 1.5 V) or SR44 (silver oxide, 1.55 V) plus a matching spacer ring mechanically bridges the compartment. Cheap and available everywhere; for cameras that need two PX825s in series (3 V), you’ll have to stack two of these adapters. Silver oxide delivers a steadier voltage than alkaline.

With the PX825, less so than with mercury types like the PX625: the original PX825 was already a 1.5 V alkaline cell, so modern 1.5 V alkaline (LR43/LR44) and 1.55 V silver oxide cells (SR43/SR44, Exell S825PX) are practically a direct electrical match. A voltage above the rated value makes the meter think there’s more light than there is → underexposure; a lower voltage, conversely, leads to overexposure. With slide film, any exposure error is critical; color negative film forgives one to two stops and is far more tolerant of over- than of underexposure.

What matters more than the absolute value is the consistency of the voltage over the discharge curve: alkaline cells (including the original PX825) drop steadily from around 1.55 V to about 1.2 V, so meter readings drift over the life of the battery. Silver oxide cells, on the other hand, hold their voltage steady over almost the entire discharge, which makes them the technically cleanest option for light meters. That said, most PX825 cameras are simple Instamatic point-and-shoots with a forgiving CdS bridge circuit, so in practice the difference rarely matters.