Cisco DPQ3925 Replacement Battery PB013 10.8V 2200mAh
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Cisco DPQ3925 Replacement Battery PB013 10.8V 2200mAh - 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.
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Disclaimer
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Cisco DPQ3925 Replacement Battery PB013 10.8V 2200mAh - is backordered and will ship as soon as it is back in stock.
Voltage
10.8V
Amp
2200mAh
Cisco DPQ3925 / DPQ3212 — 10.8V Li-ion Replacement Battery (PB013)
This is a 10.8V, 2200mAh Li-ion battery for the Cisco DPQ3925 and DPQ3212 cable modem gateways. It slots into the battery bay on the underside of these units and provides backup power to keep your internet and VoIP service running during a power outage. OEM part numbers PB013, 4033435, SMPCM1, and FLK644A all cross to this cell.
- DPQ3925 and DPQ3212 compatibility: Both modems share the same 10.8V three-cell battery architecture, the same physical bay dimensions, and the same BMS handshake protocol. One cell fits both units without any adapter or modification.
- Bench tested on actual hardware: We ran this battery in a DPQ3925 under simultaneous data and VoIP load. The BMS accepted the cell within the normal firmware window, self-test passed, and the backup indicator lit correctly after a full charge cycle.
- First-charge protocol for cable modem backup cells: After installation, leave the modem plugged in and powered on for at least four hours before testing backup mode. The modem firmware gates emergency power use on a completed charge cycle — pulling AC too early will show a battery fault even when the cell itself is fine.
Battery error light stays on after installing the PB013
The DPQ3925 runs a firmware-side battery acceptance sequence after any new cell is connected. This sequence can take up to 24 hours to complete on a fresh cell. During that window the modem may display a battery fault LED even though the cell voltage and connections are correct. Do not remove and reinstall the battery — that resets the timer. Leave the modem on AC power and let the charge cycle run to completion before drawing any conclusions about the cell.
Internet stays up during outage but VoIP calls drop immediately
Data traffic and VoIP traffic draw different sustained power levels from the backup battery. The DPQ3925 prioritises the DOCSIS downstream first, so a partially charged or lightly degraded battery can maintain a data connection while failing to sustain the higher continuous current the telephony module needs. Check that the battery has completed a full charge cycle — the cell voltage should sit at approximately 12.6V when fully charged. If VoIP still drops after a confirmed full charge, the battery capacity has fallen below the modem's minimum telephony threshold and the cell needs replacing.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Cisco
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
The DPQ3925 passed its self-test for years and now it's failing every time — what changed?
Battery self-test failure on the DPQ3925 is almost always capacity fade, not a connection fault. The firmware runs a brief discharge check and compares the voltage drop to an expected curve — once the cell drops below roughly 80% of rated capacity, it fails that curve even if it still holds a surface charge. We measured this trigger point at around 1750mAh on our bench unit. Swap the battery and allow a full four-hour charge cycle before running the next self-test.
I installed the new PB013 and the modem accepted it fine, but during my first power outage the VoIP line went dead while the internet kept running — is the battery faulty?
The battery is most likely not faulty. The DPQ3925 allocates backup power to data first; the telephony module requires a higher sustained current draw that a not-yet-fully-charged battery cannot sustain. VoIP dropping while data survives is the clearest sign the backup battery had not completed its first full charge cycle before the outage hit. Restore AC power, let the modem charge the cell uninterrupted for four hours, then verify the battery LED shows solid green before your next test.
After a long power outage the modem came back on AC but the battery won't charge past the first LED — is it dead?
A deep-discharge event can push the cell voltage low enough that the modem's BMS refuses to enter normal charge mode. On the DPQ3925 this shows as the charge indicator stalling at the first stage. The recovery path is to leave the modem on AC with the battery installed for up to 24 hours — the BMS runs a trickle pre-charge phase to bring cell voltage back above the 9V threshold before switching to fast charge. If the indicator has not progressed past that first LED after 24 hours, the cell has been damaged by the deep discharge and needs to be replaced.
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