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Flat rectangular black lithium-polymer battery, 41.5 by 30 by 5.2 mm

Cameron & Co

Cameron & Co DS-CS-MRS300SL 3.7V 650mAh Li-Polymer Battery for Marshall Major II/III Headsets

SKU CH-1JBV-HCW86

A 3.7 V 650 mAh lithium-polymer replacement cell sized 41.50 x 30.00 x 5.20 mm for Marshall Major II and III headsets

  • Restores up to 650 mAh capacity for Marshall Major II/III headsets
  • Li-polymer chemistry delivers 3.7 V nominal voltage and 2.41 Wh energy
  • Slim 41.50 × 30.00 × 5.20 mm profile fits original battery compartment
  • 100 % OEM-compatible replacement for part number VDL603040
  • Single black cell weighs 0.65 Ah in a ready-to-install package

Cameron & Co DS-CS-MRS300SL Replacement Battery

This Cameron & Co DS-CS-MRS300SL is a lithium-polymer replacement cell built for Marshall Major II and Major III headset models. It restores power to units whose original batteries no longer hold a useful charge. The part arrives new and is listed as 100 % OEM compatible. It suits owners of the Major II, Major II Bluetooth, Major III or Major III Bluetooth who want to keep their current headphones working.

Fits Marshall Headsets Without Case Modification

The cell measures 41.50 x 30.00 x 5.20 mm and matches the VDL603040 form factor used in the compatible Marshall models. It slots into the existing battery cavity so no chassis alterations or adapter cables are required. The black housing aligns with the original aesthetics. Installers should verify the connector orientation before seating the pack to avoid pin damage.

3.7 V 650 mAh Cell With Low Self-Discharge

Rated at 3.7 V and 650 mAh, the pack stores 2.41 Wh of energy for typical listening sessions. Lithium-polymer chemistry keeps self-discharge low during storage between uses. The slim 5.20 mm profile leaves the headband padding uncompressed. Users who need longer runtimes per charge or a higher-capacity alternative will not find those options in this specific replacement.

Highlights

  • Restores up to 650 mAh capacity for Marshall Major II/III headsets
  • Li-polymer chemistry delivers 3.7 V nominal voltage and 2.41 Wh energy
  • Slim 41.50 × 30.00 × 5.20 mm profile fits original battery compartment
  • 100 % OEM-compatible replacement for part number VDL603040
  • Single black cell weighs 0.65 Ah in a ready-to-install package

Specifications

BrandCameron Sino
ModelDS-CS-MRS300SL

Questions about this item

How long does the 650 mAh cell last before its capacity drops under daily charge cycles?

The lithium-polymer chemistry is rated for several hundred full cycles before noticeable capacity loss; exact cycle life depends on depth of discharge and temperature.

Does the battery get hot or draw extra power when the headset runs all day?

Normal operation stays near 3.7 V with minimal self-heating; no active cooling is required and the pack adds negligible load to the headset's power budget.

Which Marshall headset models accept the VDL603040 pack without modification?

Direct fit for Major II, Major II Bluetooth, Major III and Major III Bluetooth; the 41.5 × 30 × 5.2 mm dimensions match the original battery cavity.

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