Mitel 5613/03/DT390 reserveaccu

Keep your Mitel DECT handsets running through the busiest shifts with this dedicated spare battery pack. Unlike generic aftermarket cells, this Li-Ion unit is engineered to match the exact power profile of the 5603, 5613, and DT390 cordless phones, so you get consistent talk time and a snug, reliable fit. The 950 mAh capacity and 3.7 V output deliver steady performance for daily use, while integrated protection circuits guard against overcharge, over-discharge, and short circuits—extending the overall service life of the battery and your device.

Highlights

• Genuine Mitel replacement battery for 5603, 5613, and DT390 DECT handsets
• Lithium-Ion chemistry with 950 mAh capacity and 3.7 V nominal voltage
• Integrated overcharge, over-discharge, and short circuit protection
• Compact internal form factor designed for easy installation
• Rechargeable—simply dock the handset in its cradle to top up

In daily use

Whether you manage a busy front desk, a warehouse floor, or a healthcare environment, a spare battery means zero downtime when a handset runs low. Swap in this pack and continue calls without waiting for a charge cycle. The black housing blends seamlessly with the handset interior, and the battery is lightweight enough to carry as a backup in a pocket or drawer. Because it is a genuine Mitel part, you avoid the compatibility and safety risks often associated with third-party replacements.

Full specifications

• Brand: Mitel
• Model: 51015431
• Manufacturer Part Number (MPN): 65000640
• Battery type: Lithium-Ion (Li-Ion)
• Voltage: 3.7 V
• Capacity: 950 mAh
• Energy rating: 3.5 Wh
• Rechargeable: Yes
• Number of batteries included: 1
• Product colour: Black
• Compatible devices: Mitel 5603, Mitel 5613, Mitel DT390
• Protection features: Overcharge, over-discharge, short circuit
• Form factor: Internal phone battery
• Intended use: Replacement battery pack

Final note

For uninterrupted communication, keep a spare Mitel battery on hand—your team will thank you when the next call comes in.