Funkwerk FC4 DECT Replacement Battery 3.7V 700mAh
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Funkwerk FC4 DECT Replacement Battery 3.7V 700mAh - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
Disclaimer
Disclaimer
⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.
🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Funkwerk FC4 DECT Replacement Battery 3.7V 700mAh - is backordered and will ship as soon as it is back in stock.
Voltage
3.7V
Amp
700mAh
Funkwerk FC4 / DECT FC4 Medical — 3.7V Li-ion Replacement Battery (5010808000)
This is a 3.7V, 700mAh lithium-ion battery for the Funkwerk FC4 and DECT FC4 Medical cordless handsets. It replaces OEM part numbers 5010808000 and 5010808030. When the original cell degrades and talk time drops, this swap restores the handset to full operation without touching the base station or pairing setup.
- FC4 and FC4 Medical platform: Both the standard FC4 and the DECT FC4 Medical share the same handset chassis, battery compartment dimensions, and connector pinout — one cell fits the full range. The Medical variant draws the same standby and transmit current as the consumer unit, so there is no electrical difference in the battery requirement.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the FC4 platform and monitored BMS behaviour across the full voltage window. The protection circuit tripped correctly at the low-voltage threshold and accepted charge without fault at the base station contacts.
- First charge after installation: Seat the handset in the FC4 base immediately after fitting and leave it for a full charge cycle before first use. Li-ion cells shipped in partial state of charge need one complete controlled charge to let the BMS calibrate its capacity tracking correctly.
Why the FC4 handset loses range shortly after a battery swap
DECT transmitters pull a short burst of higher current each time the handset communicates with the base. If the replacement cell is at low state of charge from storage, its internal resistance causes voltage to sag under that RF burst load. The base station interprets weak or broken signal as range loss — but the handset has not moved. A full charge cycle before use eliminates this behaviour because the cell can sustain voltage under the transmit pulse.
Handset not pairing with the base after battery replacement
Removing the battery from a DECT handset cuts all power to the pairing memory on some FC4 firmware versions. The handset powers back up without a stored link and sits in an unregistered state. To fix this, hold the handset's paging or find button while it is seated in the base — this re-initiates the DECT registration handshake. Once the base confirms registration, normal operation resumes.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Funkwerk
- Manufacturer: CS
- Series: Standard
- Color: Silver
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My Funkwerk FC4 talk time is noticeably shorter than the old battery after the swap — is that normal?
Yes, and it corrects itself after a few full cycles. A new Li-ion cell ships at partial charge, and the BMS capacity estimate is not yet calibrated to the actual cell. Run two to three complete charge and discharge cycles through normal use — each cycle lets the BMS refine its tracking window. By the third cycle, measured capacity should be sitting close to the rated 700mAh.
The FC4 base station shows no charge indicator or an error light after I fitted the new battery — what's wrong?
This usually means the cell voltage dropped low enough during shipping or storage that the base's charge controller rejected it. Place the handset in the base and leave it undisturbed — the base will attempt a trickle pre-charge to bring the cell above the acceptance threshold, typically around 3.0V. Once the cell crosses that threshold, the charge controller switches to normal CC/CV charging and the indicator should come on within 15–30 minutes.
The FC4 handset drains completely overnight even when it's sitting in the base — what's causing that?
This points to a seating issue rather than a battery fault. If the handset is not fully clicked into the base cradle, the charge contacts do not make a consistent connection and the handset runs on battery in standby instead of drawing from the base. Remove the handset, check the base contacts for dust or corrosion, then re-seat the handset until you feel it click. Confirm the charge indicator lights up immediately after re-seating.
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