● R1MX
REPAIR Available

NVRAM Battery Replacement

Fix the battery that causes time resets and lost settings on every boot.

Difficulty Medium
Time 45-90 minutes
Tools
  • Torx T6 screwdriver
  • Torx T8 screwdriver
  • Phillips PH0 screwdriver
  • Soldering iron (fine tip, 300-350 C)
  • Solder wick / desoldering braid
  • Rosin flux (no-clean)
  • Multimeter
  • Tweezers
Parts
  • Panasonic ML2020 rechargeable coin cell (3V, Li-Mn) - NOT CR2020

Overview

The RED ONE MX uses a small rechargeable lithium-manganese coin cell to maintain NVRAM (non-volatile memory) when the main battery is removed. This cell keeps the real-time clock and persistent settings alive between shoots.

When this cell dies, the camera loses all memory of settings and resets its clock to a default time (typically 1:00 AM) on every boot.

The cell is soldered directly to the power board - it is not in a socket. Replacement requires partial disassembly and basic soldering skills.

The correct part is the Panasonic ML2020 - a rechargeable (secondary) cell. Do not substitute a CR2020 primary cell. The charging circuit on the power board is designed for a rechargeable cell; installing a primary cell may overheat or rupture it.
Source: Battery identified by Kyle Simukka at Dead NVRAM battery in RED ONE MX - ML2020 (REDuser.net, 2020).

Symptoms

This guide applies if you observe all three of these symptoms:

Symptom Notes
Clock resets to a fixed time on every boot Typically resets to 1:00 AM or a date in 2001/2009
All custom menu settings lost after power cycle White balance, ISO, project settings, etc.
Camera otherwise functions normally Boots, records, outputs video correctly

If the camera also fails to boot, see the No-Boot Diagnosis guide first (planned).

Part Sourcing

The Panasonic ML2020 is widely available from electronics distributors:

Supplier Notes
Mouser Electronics Search “ML2020” - stocked as Panasonic ML2020/F2N or similar
Digi-Key Same part family, multiple package variants
eBay Available in bulk packs from Japan - verify “ML” not “CR” before ordering

The cell costs $2-5 USD. Order 2-3 in case of installation issues.

Steps

1
Confirm the diagnosis before disassembling.

Boot the camera with a charged main battery. Note the current time shown in the menu. Remove the main battery for 30 seconds. Reinstall and boot again. If the clock has reset, the NVRAM battery is dead or nearly dead. Proceed with replacement.

📷 Photo needed: Camera menu showing the time/date settings page
2
Fully discharge the main battery and remove all power from the camera.

Remove the main battery pack. Remove any external power supply (DC input). Allow the camera to sit unpowered for at least 5 minutes before opening.

3
Remove the rear panel to access the internal boards.

The RED ONE MX rear panel is held by Torx T8 screws around the perimeter. Remove all screws and carefully separate the panel. The various cable harnesses are short; do not force the panel away from the body. Set it aside in a safe location.

📷 Photo needed: Rear panel with Torx screw locations marked
4
Locate the power board and the ML2020 cell.

The power board is identifiable by the large power input connector and the cluster of power management ICs. The ML2020 coin cell is a small round silver cell (20mm diameter, 2mm thick) soldered with its positive terminal marked "+" on the board silkscreen.

The cell is typically located near the edge of the power board, away from the high-density component areas. It is soldered through two small through-hole solder points or with surface-mount clips depending on board revision.

📷 Photo needed: Close-up of power board showing ML2020 location. Contribution welcome - see Contributing Guide.
5
Measure the old cell voltage before removing it.

Use a multimeter to measure the voltage across the cell in-circuit (positive probe to +, negative probe to -). A healthy ML2020 reads 2.8-3.0V. If you read below 2.5V, the cell is confirmed dead. If you read 0V, it may be shorted or completely exhausted.

Record the voltage for your notes. This is useful for debugging if symptoms persist after replacement.

6
Remove the old cell using desoldering braid.

Apply flux to the solder joints. Use desoldering braid and the soldering iron to remove the solder from each joint. Once the solder is cleared, the cell should lift out freely. Do not apply excessive heat. The cell is small and will heat up quickly; work in short bursts to avoid damage to the surrounding pads.

7
Install the new ML2020 cell, observing polarity.

Verify the "+" marking on the board before placing the new cell. Place the ML2020 with the positive side (marked "+" on the cell itself) matching the board silkscreen. Apply a small amount of fresh solder to each joint. The joints should be smooth and shiny.

8
Verify installation with a multimeter.

Measure voltage across the new cell before reassembling. A new ML2020 should read 3.0V or very close to it. If you read near 0V, the polarity may be reversed - check and correct before proceeding.

9
Reassemble and test.

Reinstall the rear panel. Install the main battery and boot the camera. Set the correct time and date in the camera menu. Remove the battery for 30 seconds. Reinstall and boot. If the clock has retained the correct time, the replacement was successful.

Allow the camera to run for a full charge cycle so the charging circuit can top off the new cell. The ML2020 will charge from the main battery while the camera is powered on.

Troubleshooting

Problem Possible cause Action
Clock still resets after replacement Cell installed with reversed polarity Remove and reinstall, checking + marking
Clock still resets after replacement Cold solder joint Reheat both joints with fresh flux
Camera does not boot after reassembly Loose connector or cable disturbed during reassembly Open rear panel and check all cable harnesses
Measured voltage on new cell is 0V Reversed polarity shorted cell Replace cell - a shorted Li-Mn cell should be safely discarded

See Also