Which battery replaces the PX825?

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

The PX825 was mainly used in the Kodak Instamatic series: Kodak Instamatic 124, 154, 174, 204, 224, 304, 314, 404, 500, 704, 714, 800, 814, Instamatic Reflex, and S10/S20. Other manufacturers’ models include 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 require two PX825 batteries in series (3 V total). You can find the complete searchable list of 43 camera models at the top of this page.

Original PX825 batteries have practically not been produced since the early 1990s. Production was discontinued for commercial reasons. Demand for 23.2 mm button cells for vintage Instamatic cameras simply became too low, and the mechanical form is uneconomical compared with modern, significantly smaller standard alkaline and silver-oxide cells. Important for context: The PX825 was an alkaline cell from the outset, so EU mercury bans (Battery Directive 2006/66/EC, Batteries Regulation 2023/1542) do not affect it. Replacements are nevertheless readily available today, both as a form-fitting drop-in replacement (e.g., the Exell S825PX in silver oxide, also found as LR53/BLR53/KA825) and through adapter solutions.

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

• Exell S825PX (silver oxide, 1.55 V). The direct drop-in: Form-factor-identical replacement with the original dimensions of 23.2 × 6.1 mm. No adapter needed—just insert it. Silver oxide delivers a constant voltage over almost the entire discharge curve. Available from specialist retailers such as mdbattery or smallbattery.company.org.uk. Also found under the designations LR53, BLR53, and KA825.
• Adapter with two small 1.5 V cells (Ausgeknipst solution): A plastic adapter fills the large PX825 compartment and holds two modern LR43/LR54 or silver-oxide SR43/SR54 cells, connected in parallel to provide the nominal 1.5 V. Advantages: standard cells available everywhere, long shelf life, and an exact voltage match for the original alkaline PX825. Available from Ausgeknipst as the PX825 adapter with two cells.
• LR44/SR44 with spacer ring: A single LR44 (alkaline, 1.5 V) or SR44 (silver oxide, 1.55 V) plus a suitable spacer ring bridges the compartment mechanically. Inexpensive and widely available; for cameras that require two PX825 cells in series (3 V), two of these adapters must be stacked. Silver oxide provides a more consistent voltage than alkaline.

Less so with the PX825 than with mercury types such as the PX625: The original PX825 was already a 1.5 V alkaline cell, so modern 1.5 V alkaline cells (LR43/LR44) and 1.55 V silver-oxide cells (SR43/SR44, Exell S825PX) are electrically almost direct replacements. A higher voltage than the target value makes the light meter assume there is more light → underexposure; a lower voltage conversely leads to overexposure. With slide film, any incorrect exposure is critical; color-negative film tolerates one or two stops and is noticeably more forgiving of overexposure than underexposure.

More important than the absolute value is the consistency of the voltage over the discharge curve: alkaline cells (including the original PX825) continuously drop from around 1.55 V to approximately 1.2 V. This leads to fluctuating meter readings over the battery’s service life. Silver-oxide cells, by contrast, maintain a constant voltage over almost the entire discharge and are therefore the technically cleanest option for light meters. However, since most PX825 cameras are simple Instamatic point-and-shoots with a tolerant CdS bridge circuit, the difference rarely matters in practice.