Battery type 4LR44 — Compatible Cameras

The 4LR44 is a 6-volt alkaline battery, internally made of four cylindrically stacked LR44 button cells (each 1.5 V) in a common casing. Dimensions: 13 × 25.2 mm. It has been used since the late 1970s in numerous electronically controlled SLR cameras as a replacement for the previously common mercury-containing PX28 — manufacturers include Varta, Duracell, GP, and Energizer.

4LR44 is the standard power supply for the entire Canon A series — that is Canon AE-1, AE-1 Program, A-1, AL-1, AT-1, AV-1 — as well as for the Canon New F-1 and F-1N. Other typical cameras are the Bronica medium format series (ETR, ETR-S, ETR-Si, SQ, SQ-A, GS-1, EC-TL), the Hasselblad 2000 series (2000 FC / FCW), Contax RTS and RTS II, as well as various Fuji/Fujica AX and ST models. The complete searchable compatibility list with 144 camera models can be found at the top of this page.

The same cell is sold under many names — depending on manufacturer, market, and chemistry:

• 28A (ANSI/NEDA designation)
• PX28A, PX28AB — Alkaline
• A544 (Varta), V4034PX (Varta), V28PXL
• GP476A (GP), L1325 (Duracell)
• 4SR44 / S544 — Silver oxide variant, 6.2 V (slightly higher voltage)
• PX28 without suffix — the historic mercury version (5.6 V, now banned EU-wide)
• PX28L / 2CR1/3N — Lithium variant (see next question)

Several cell chemistries can deliver the same 6 V — each with its own strengths and weaknesses:

• 4LR44 / 28A (Alkaline, 6.0 V): Standard, cheaply available everywhere. Voltage continuously drops over the lifetime — uncritical for cameras with voltage regulators (Canon AE-1/A-1, see below), but in simpler circuits the readings can drift near end of life.
• 4SR44 / S544 (Silver oxide, 6.2 V): Slightly higher voltage, but very consistent discharge curve and longer runtime. More expensive than alkaline, available in photo specialty stores.
• 2CR1/3N / PX28L (Lithium, 6.0 V): Two lithium 3V cells in one housing. Most constant voltage level over the entire discharge, cold-resistant, long shelf life. Significantly more expensive.
• Adapter with 4 × LR44 individual cells: A sleeve adapter into which four separate LR44 button cells are stacked — the cheapest solution because LR44 is sold individually everywhere as a standard button cell. At Ausgeknipst as 4LR44 adapter.

Basically, for analog light meters without a voltage regulator: Higher voltage than specified causes the light meter to accept too much light → slight underexposure; lower voltage leads to overexposure. However, the main cameras in this class — the Canon A-series (AE-1, AE-1 Program, A-1, AT-1, AV-1) — have an internal voltage regulator in the electronics that reduces the supply voltage from about 3.6 V to 7 V to a constant operating value. In this range, alkaline (6.0 V), silver oxide (6.2 V), and lithium (6.0 V) deliver practically identical readings — the voltage difference of the three chemistries is uncritical here.

More important than the absolute value is the consistency of the voltage over the discharge curve: Alkaline declines slowly, silver oxide and lithium maintain their value almost until the end. With modern Canon bodies this is secondary due to the regulator; with older or unregulated light meters, a lithium or silver oxide cell is the technically cleaner choice.