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Small rectangular lithium battery pack, flat black finish, thin profile

Estry

Estry Replacement Battery for Forerunner 305i 305 205 361-00026-00 700mAh 3.7V

SKU CH-WEXF-WC2RG

Lithium replacement battery for Forerunner 305i, 305 and 205 GPS watches, 700 mAh at 3.7 V with overcharge and short-circuit protection

  • Battery pack size1-pack
  • Battery typeLithium
  • Battery capacity700 mAh
  • Battery voltage rating3.7
  • Product typeBatteries
  • Compatible with Forerunner 305i, 305 and 205 models
  • 700mAh capacity restores original runtime for longer activities
  • 7V lithium cell matches OEM voltage for safe operation
  • Built-in protection against overcharge, over-discharge and short circuits
  • Certified to ISO9001, RoHS, CE, UN38.3 and MSDS standards

Direct replacement for Forerunner 205 305 305i

This Estry lithium cell matches the original 361-00026-00 specification at 3.7V and 700mAh. It fits the Forerunner 205, 305 and 305i models without modification. The 2.59Wh pack restores factory run time for daily training sessions.

Protection circuitry and certified safety

Built-in overcharge, over-discharge, over-voltage and short-circuit protection guards the cell during normal charging cycles. The pack carries ISO9001, RoHS, CE, UN38.3 and MSDS certifications confirming compliance with international safety standards. No special cooling or ventilation is required in typical use.

Compact form factor with proven fit

Measuring 38.9 x 34.25 x 5.5mm and weighing 39.0g, the battery slides into the existing compartment using the original connector layout. The single-pack design means no wiring changes or adapter cables are needed. Buyers who need a multi-cell pack or a different voltage should verify compatibility before ordering.

How it compares

Measured against everything we stock in Household Batteries & Chargers, at today’s prices. Recalculated every night.

Price $8.99
Cheaper than about 80% of the 10,440 comparable items (median $10.99).

Specifications

Product
Product typeBatteries
Power
Battery typeLithium
Battery capacity700 mAh
Battery voltage rating3.7
In the box
Battery pack size1-pack

Questions about this item

How do I install the Estry battery in my Forerunner 305i and which step do people often get wrong?

Open the rear case, disconnect the original 361-00026-00 pack, connect the new 3.7V 700mAh lithium cell matching the 38.9 x 34.25 x 5.5 mm cavity, then reseal. The step most people miss is aligning the connector polarity before snapping the cover shut.

What maintenance or replacement will this 700mAh lithium pack need later?

The cell has built-in overcharge, over-discharge, over-voltage and short-circuit protection, so no routine maintenance is required. Plan to replace the pack once runtime drops noticeably — typically after several hundred charge cycles.

What limit appears first during sustained GPS use with this 2.59 Wh battery?

The 700mAh capacity is the first limit; continuous GPS logging will drain the 3.7V pack in a few hours before any thermal or voltage protection activates.

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