Why Won’t My LiPo Battery Charge? HOTA and WhoopStor Diagnostics

First decide whether another charging attempt is safe

Inspect the disconnected pack and leads. Swelling, damaged wrapping, loose wiring, or burned contacts are reasons to stop. Let a normally warm pack cool within its manufacturer's charging-temperature limits. A pack that becomes abnormally hot or swells during charging needs the charging process stopped; disconnect the charger's power only if safe, and do not keep handling the battery.

Match chemistry, cell count, voltage, and charge current to the battery label and instructions. If its voltage is below the manufacturer's minimum safe starting voltage, do not charge it. Do not use a NiMH program, a different chemistry, or a second battery to force a rejected LiPo into accepting charge. Horizon Hobby's lithium-battery safety instructions support these checks and require attended charging away from combustible materials.

If the battery identity or permitted settings are unreadable, that missing information is the next problem to resolve. A connector that fits does not establish the correct charging program.

HOTA D6 Pro: distinguish startup, connection, and task faults

Power the charger and let self-check finish before connecting an output pack, as specified in the D6 Pro instructions, version 1.1.8.

1. Self-check error: Remove the output battery, wait five seconds, and retry. Allow self-check to finish before reconnecting.
2. Connection error: Stop the task, inspect the connections, and reseat undamaged connectors. Recurring errors require checking contacts for oxidation or burning.
3. Missing cell information: Connect the main and balance leads of a multi-cell pack to the same channel. The balance lead exposes individual cell voltages. Do not bypass a balance warning.
4. Unexpected stopping: Storage mode targets storage voltage; safety-time and capacity limits can also stop a task. Do not disable protection to suppress an unexplained stop.

The manual describes brief current changes during resistance measurement. Persistent warnings need support. For broader model suitability, see the D6 Pro guide.

WhoopStor 3: check input power and the target before blaming a port

According to VIFLY's WhoopStor 3 specifications, ordinary 5 V USB power is unsupported. The published USB-C input range is 9–20 V, with 40 W minimum input power. Check the power supply's supported output profiles and cable, not just the USB-C plug shape. Use one supported power input; a plug fitting the socket does not prove the supply is suitable.

Its six channels accept PH2.0 or BT2.0. Match the connector without forcing it; the 1S connector guide explains how to distinguish the common types.

Choose the battery-approved target: 3.80/3.85 V storage or 4.20 V LiPo/4.35 V LiHV charge. Storage mode can discharge a pack above its target. A storage-voltage finish is not a charging refusal. Never select LiHV for an ordinary LiPo.

Recheck the remembered current. VIFLY lists 0.3–1.3 A per port; if 0.3 A exceeds the pack's permitted current, this charger is unsuitable.

The WhoopStor 3 manual allows only one battery in each numbered PH2.0/BT2.0 pair. A long press of Start/Stop starts or stops the task. Check the screen status before assuming that a connected pack is charging.

The manual also limits current to 0.6 A with a USB supply offering only 9 V. Low source power can disrupt operation; reduce the connected load or current within the battery-approved range. A running screen alone does not prove the supply can sustain charging. Keep ventilation clear.

Use the pattern to narrow the fault

After the inspection and settings checks, record what fails before buying anything. The following is a diagnostic interpretation of the two chargers' power, connection, and task requirements, not a guaranteed component diagnosis.

Change one item at a time and keep the result. A note such as “same healthy pack, same approved settings, channel 1 fails and channel 2 works” gives support more to investigate than “battery will not charge.” Stop the task before changing connections. Never introduce a suspect battery into a test merely to complete the comparison.

Check firmware after the physical and power checks

The VIFLY download center lists WhoopStor V3 firmware V1.17 as checked September 9, 2026, separately from V2 V1.13. It describes an algorithm improvement and links an upgrade guide. That release note does not establish that an update fixes every charging error.

Use HOTA's own service page for the D6 Pro firmware and manual links. It separates D6, D6 Pro, and D6+. On September 9, 2026, its D6 Pro archive contained a file named HOTA D6 Pro V1.0.53.prg. That filename identifies the offered file, not a confirmed fix for your fault. Match the exact model and follow the update instructions; the manual's version is not the installed firmware version.