For WhoopStor 3 charging problems, first check the battery's condition, then the input supply, saved settings and affected connection. Stop for swelling, heat or damaged connectors. An unfamiliar error message is a reason to record the screen and investigate, not permission to keep restarting. VIFLY's available manual does not provide a numbered error-code lookup table.
A persistent warning after the external checks needs support guidance. Keep damaged or suspect batteries out of the diagnosis, and never treat a restart or firmware update as proof that the problem is fixed.
Featured gear
VIFLY WhoopStor 3 1S Battery Charger
The VIFLY WhoopStor 3 charges or storage-charges as many as six 1S LiPo or LiHV tiny-whoop batteries through independent PH2.0 and BT2.0 channels. Best for: Pilots managing multiple 1S tiny-whoop batteries. Not ideal for:…
The VIFLY WhoopStor 3 charges or storage-charges as many as six 1S LiPo or LiHV tiny-whoop batteries through independent PH2.0 and BT2.0 channels.
- Best for
- A specialized six-channel charger and storage discharger for 1S PH2.0 and BT2.0 tiny-whoop batteries;…
- Product type
- Battery Chargers
- Best for
- A specialized six-channel charger and storage discharger for 1S PH2.0 and BT2.0 tiny-whoop batteries;…
- Product type
- 1S Battery Charger and Storage Discharger
Read the message and the right voltage
Photograph the complete screen before changing anything. Record whether the problem appears at power-on, when a battery is connected, after starting, or only with several channels working. Those are different clues. Include the selected current, target voltage, input voltage and affected channel number.
The WhoopStor 3 manual places supply voltage at the top center and individual battery readings below. A low supply reading concerns the source powering the charger; a low channel reading concerns a connected 1S pack. Do not apply a limit for one to the other.
VIFLY documents OK! as completion. It is not a battery-health certificate. For any other message whose meaning is unclear, give VIFLY the exact text and firmware version rather than using another charger's code list. The manual and current download page do not establish a universal code-to-repair mapping.
Work through these checks before starting again
This conservative sequence helps separate a setup issue from a condition that needs service. It does not identify a failed component from a message alone. Keep suspect batteries out of the checks.
- Inspect with charging stopped. Look for swelling, damaged insulation, loose or melted connectors, leaks and abnormal heat. Do not charge a damaged pack or use a damaged charger. If a battery is reacting or smoking, keep clear rather than trying to complete the checks.
- Identify the battery. Confirm the 1S chemistry, permitted charge voltage and current from its own label or instructions. If those cannot be established, leave it disconnected. Our FPV battery guide explains the label and charging limits.
- Check power with output batteries removed. Read the supply's output modes and compare them with VIFLY's limits below. Inspect the cable and plug. A screen that fails before a charging load is attached deserves a different investigation from one that resets only under load.
- Recheck the remembered settings. Verify target voltage and current before connecting a healthy, compatible pack. Start with one pack so that an abnormal reading can be tied to one connection.
- Observe before adding more packs. If readings or temperature become abnormal, stop. If normal operation returns after correcting a clearly wrong setting or supply, record that change. A brief successful session does not establish that a damaged component is safe.
iFlight's battery safety guidance supports the inspection and stop conditions: let batteries cool before charging, stay present, use a nonflammable surface and suitable fire-resistant containment, and stop for hot, swollen, leaking or abnormal behavior. Keep the charger ventilated. Do not force a rejected pack to accept charge by changing chemistry or bypassing protection.
Match the symptom to the next check
Start with the row closest to what you can actually observe. The last column limits how far the check should go.
| Symptom | Next check | When to stop |
|---|---|---|
| No useful screen on USB-C | Check the supply's supported output modes and the cable before attaching batteries. | A compliant, undamaged supply still gives no readable display: seek service. |
| Resets when charging starts | Compare input capability with the connected load; note whether the input reading changes. | Repeated resets on a suitable supply, or any heat or damage: discontinue use. |
| One pack is not detected or gives an implausible reading | Stop, disconnect and inspect its plug, polarity and the selected socket. | A damaged pack, loose contact or persistent abnormal reading needs attention before another attempt. |
| One channel repeatedly reports a fault | Record channel number, connector type and settings. Compare only observations already obtained with healthy packs. | Do not keep moving a suspect pack between ports or open the charger to chase the fault. |
| Charging ends below the intended full voltage | Check whether a storage target was selected. | The selected correct target and displayed outcome disagree repeatedly: ask VIFLY to assess it. |
| Discharging is slower than expected | Check whether the task is reducing voltage toward storage; the charging-current control does not set discharge current. | Abnormal heat, stalled readings or a warning means stop, not increase the target. |
If a plug will not seat normally, do not force it. The manual permits one battery per numbered PH2.0/BT2.0 socket pair. For help identifying the connector before reconnecting, see our 1S battery connector comparison. A physical fit alone does not establish the correct chemistry or polarity.
Rule out input limits and the wrong task
VIFLY's specifications list a 40W minimum input supply, 6–26V through XT60/DC and 9–20V through USB-C. Ordinary 5V USB power is unsupported. Read the actual output modes, not just a supply's headline wattage. The manual limits charging to 0.6A when the USB source can supply only 9V.
For insufficient input power, the manual suggests reducing charging current or the number of connected batteries. That does not make an incompatible supply acceptable. A reset that disappears with fewer packs points toward checking the supply and cable under load, but does not prove either one is defective. Change one factor at a time and keep the battery's permitted current as the ceiling.
When using a 2S–6S input battery, the manual describes charging stopping below 3.5V per input cell and the screen entering power-saving mode below 3.3V per cell. These describe the input-pack behavior in that manual, not thresholds for rescuing a discharged output battery. Disconnect the input pack and output batteries; do not repeatedly restart to extract more energy.
WhoopStor 3 remembers settings and offers 3.80V/3.85V storage targets, 4.20V LiPo charging and 4.35V LiHV charging. A storage target can explain why a healthy pack is not being fully charged. Use 4.35V only when the battery explicitly permits it. Starting voltages may differ between independent channels, but every connected pack must tolerate the selected target and current.
The current range is 0.3–1.3A. Maximum capability is not a safe default for every pack. If even the minimum exceeds the battery's allowed rate, do not charge that pack here. Storage discharge is separately limited: VIFLY specifies 1.1W per port, and the manual says discharge current is not adjustable and cannot exceed 0.3A. Turning up charge current will not accelerate that task.
Check firmware without promising a cure
On September 9, 2026, the VIFLY Download Center listed WhoopStor V3 firmware V1.17, separately from V2 firmware. Its brief release note describes an algorithm improvement; it does not identify a fix for every charging error, display failure or faulty port.
Record your installed version and confirm that the unit is V3 before selecting an update. If a failed display prevents reading the version, report it as unknown. Follow the official upgrade guide linked from that page. Do not substitute the V2 file or repeat failed flashing attempts without guidance. If an error appeared after an update, preserve the file version and the sequence of events for support.
Give support a reproducible description
Contact VIFLY through its official website or the seller with the exact message, screen photograph, firmware version, input supply's output ratings, battery label, selected settings and affected channel. Say whether the fault occurs with no outputs attached, at start, or under load. Include any damage or overheating; do not conceal those observations behind “not charging.”
A persistent channel fault or unreadable display after the external checks calls for service guidance. Avoid board repairs, connector bending or protection bypasses as charging workarounds. If replacement becomes necessary, the WhoopStor 3 review covers the model's suitability and limitations. Establish what failed before buying another charger or discarding healthy batteries.
Sources
- VIFLY WhoopStor 3 specifications: Manufacturer input limits, current range, voltage targets and storage features.
- VIFLY WhoopStor 3 manual: Manufacturer document hosted by Colin's Radio Control; screen layout, paired sockets, completion indication and operating limits. No numbered error-code table or firmware revision is printed.
- VIFLY Download Center: Current V3 firmware listing and official upgrade-guide link.
- iFlight battery charging and safety guide: Manufacturer guidance on battery condition, charging environment and stop conditions.
Last checked: September 9, 2026.
