A portable power station shows 0 watts but drains when the display does not reflect all the energy the unit is using. Possible causes include inverter standby consumption, small connected loads, and internal electronics that remain active while the station is powered on.
The most relevant possibilities are:
A load below the display’s reporting threshold: A connected device may draw power without producing a visible wattage reading.
AC inverter standby consumption: The inverter may use energy while AC output is enabled, even when no appliance is connected.
Other active outputs or internal functions: USB or DC devices and the station’s operating electronics may contribute to energy use.
What to check first: Disconnect external devices, disable unused outputs according to the manual, and record the battery percentage and observation time. If the charge continues to fall, compare supported operating states and check the manufacturer’s documentation for your exact model. A 0 W reading alone does not establish a fault.
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Quick Answer: Why a Portable Portable Power Station Shows 0 Watts But Drains
If your portable power station shows 0 W while the battery percentage decreases, the display may be reporting output power without capturing every source of battery consumption. The most relevant possibilities are:
A load below the display’s reporting threshold: A connected device may draw power without producing a visible wattage reading.
AC inverter standby consumption: The inverter may use energy while AC output is enabled, even when no appliance is connected.
Other active outputs or internal functions: USB or DC devices and the station’s operating electronics may contribute to energy use.
What to check first: Disconnect external devices, disable unused outputs according to the manual, and record the battery percentage and observation time. If the charge continues to fall, compare supported operating states and check the manufacturer’s documentation for your exact model. A 0 W reading alone does not establish a fault.
Can a Power Station Show 0 W Even When It Is Using Energy?
Yes. A portable power station can display 0 W while still supplying a small load or consuming energy internally. The key distinction is that the wattage shown on the screen may represent measured output power, not every watt drawn from the battery.
The display alone therefore cannot confirm whether the station is using energy. To understand what is happening, consider the size of the connected load, the model’s display behavior, and whether the station’s own electronics or enabled outputs are consuming power.
Why Small Loads May Not Appear on the Display
Some portable power stations may show 0 W when a connected device draws less power than the display can register or report. The device may still be operating normally, even though the screen does not show its actual consumption.
For example, Jackery Support states that certain Jackery power stations may display 0 W when an AC-connected device consumes less than 25 W. This is a model-specific example, not a universal threshold for portable power stations. Source: Jackery Support
This can make low-power devices particularly confusing to troubleshoot. A small electronic accessory may continue drawing power even when the displayed output remains at zero. However, a 0 W reading does not by itself prove that a hidden load exists; it only means the display is not reporting measurable output at that moment.
How Display Measurement Limits Vary by Model
Portable power stations do not all use the same display logic. The minimum reported load, measurement resolution, and behavior of the AC and DC output readings can differ between models. Some screens also distinguish between input power and output power, so it is important to identify which value you are viewing.
Before treating 0 W as evidence of a fault—or assuming that a small load is being hidden—check the manufacturer’s manual or support documentation for your exact model. Only quote a specific wattage threshold when the manufacturer confirms it.
Do not apply the 25 W example above to another brand or model without verification. A display that reports small loads accurately may behave differently from one that rounds or suppresses low readings.
Output Power vs. Internal Power Consumption
Displayed output power and total battery energy consumption are related, but they are not the same measurement.
Output power is the power delivered through the station’s output ports, as reported by its monitoring system. Internal power consumption is the energy used by the station itself to operate its electronics and other active components. Depending on the model and operating state, this may include inverter standby consumption, control circuitry, and other internal functions.
Consequently, the display can show 0 W of output while the station still draws energy from its battery. For example, the AC inverter may consume standby power while the AC output remains enabled, even when no external device is connected. The amount depends on the particular station and its operating state.
The distinction also matters when interpreting battery percentage. A falling state-of-charge reading may indicate that energy is being used, but the percentage alone does not identify the cause or quantify the exact power consumption.
| What the display shows | What may be happening |
|---|---|
| 0 W output with a small device connected | The device may be drawing a load below the display’s reporting threshold. |
| 0 W output with AC enabled and nothing plugged in | The inverter or other active electronics may be consuming standby power. |
| 0 W output with all external devices disconnected | Internal consumption may continue if the station remains powered on or outputs remain enabled. |
| 0 W output and an apparently unchanged battery percentage | Small energy changes may not immediately produce a visible change in the displayed percentage. |
| 0 W output while the battery percentage decreases | The station may be consuming energy, but further checks are needed to identify the source. |
Practical takeaway: Treat 0 W as a reading of reported output, not proof that the station is consuming no energy. Disconnect external devices, switch off unused outputs, and observe whether the battery level continues to decline. Consult the manual for model-specific display behavior before drawing conclusions.
Can the AC Inverter Drain the Battery With Nothing Plugged In?
Yes. A portable power station can lose battery charge while nothing is plugged into its AC outlets if the AC inverter remains enabled. The inverter converts the battery’s DC power into AC electricity, and keeping this circuitry active can consume energy even when no appliance is drawing power.
This is different from energy used by connected devices and from battery self-discharge during storage. To determine whether the inverter is responsible, you need to compare the station’s behavior with AC output enabled and disabled under otherwise similar conditions.
What Is Inverter Standby Power?
Inverter standby power is the energy consumed by the inverter while it is enabled but delivering little or no useful output to external devices.
The inverter and its associated control circuitry must remain operational while AC output is available. Depending on the power station’s design, this can draw energy from the battery even when every AC outlet is empty. Other active components may also consume power, so the total battery drain cannot automatically be attributed to the inverter alone.
The amount of standby consumption varies by model and operating state. Some manufacturers document this consumption directly; others do not publish a specific figure. For example, the AC50P user manual provides a model-specific self-consumption figure for runtime calculations. That figure should not be applied to other power stations. Source: AC50P user manual
It is also important to distinguish standby consumption from battery self-discharge.
If you want to understand how a battery can lose charge when the power station is not actively operating, see our guide to how much power a portable power station loses in storage.
Standby consumption occurs while the station is operating with the inverter enabled. Self-discharge refers to the battery gradually losing stored charge over time, including when the station is not actively supplying power. These are separate mechanisms and require different troubleshooting approaches.
Does Turning Off AC Output Reduce Battery Drain?
Turning off AC output can reduce battery consumption if the inverter is responsible for some of the drain. However, the result depends on the power station’s design and which functions remain active after the AC output is disabled.
On models with a dedicated AC output button, switching AC output off disables the AC outlets. EcoFlow’s DELTA 2 manual, for example, identifies a separate AC power button for controlling AC output. The exact behavior of the inverter and other internal systems should still be checked against the relevant model’s documentation. Source: EcoFlow DELTA 2 user manual
Keep these distinctions in mind:
AC output enabled, no device connected: The inverter may consume standby power.
AC output disabled: Inverter-related consumption may decrease, but the station may still use energy for other active functions.
USB or DC outputs enabled: Connected devices or active output circuitry may continue drawing energy independently of the AC inverter.
Station fully powered down: Consumption may be lower, but the remaining power draw depends on the model and its shutdown state.
Do not assume that switching off the AC output completely stops battery drain. If the station continues losing charge with all outputs disabled, investigate other possible causes rather than concluding that the inverter is faulty.
How to Check Whether the Inverter Is Responsible
You can perform a simple comparison to determine whether enabling AC output appears to increase battery drain. This is a practical troubleshooting test, not a substitute for a calibrated power measurement.
Disconnect external devices. Unplug all appliances and accessories from the station, including devices connected to AC outlets. Turn off USB and DC outputs if they are not needed for the test.
Record the starting conditions. Note the battery percentage, whether the station is charging, the ambient temperature if relevant, and which outputs are enabled. Keep the station disconnected from external charging sources throughout the comparison.
Test with AC output enabled. Turn on AC output without connecting any appliances. Leave the station in this state for a defined period and record the battery reading at the end.
Repeat with AC output disabled. Under similar conditions, repeat the observation for the same length of time, with the other outputs and operating settings unchanged. If possible, start both tests at a similar state of charge and temperature.
Compare the results. If the battery level declines more during the AC-enabled test, that supports the possibility that inverter operation contributes to the drain. It does not establish the exact power consumption or prove that the inverter is the only cause.
Check the manual. Look for information about inverter standby consumption, AC output controls, automatic shutdown, and power-saving modes. If the drain remains unexpectedly high with AC output disabled and external devices disconnected, consult the manufacturer’s troubleshooting guidance or support team.
| Test condition | What to observe | What the result may indicate |
|---|---|---|
| AC enabled, no devices connected | Battery change over a defined period | May include inverter standby consumption and other internal operating loads |
| AC disabled, other settings unchanged | Battery change over the same period | Helps establish a comparison baseline |
| AC and other outputs disabled | Whether the battery continues to decline | May indicate other internal consumption or another issue requiring investigation |
| Station powered down according to the manual | Battery change over a longer observation period | Helps distinguish operating consumption from charge loss while powered down |
Important: Battery-percentage readings are estimates and may be too coarse to reveal small differences during a short test. Use longer, comparable observation periods where practical, and avoid repeatedly draining the battery to a low level just to measure standby consumption. If the manufacturer provides a suitable measurement procedure or reliable energy data, use that information instead.
The key takeaway is that an enabled AC inverter can contribute to battery drain even with nothing plugged in. Comparing otherwise similar AC-on and AC-off conditions is a useful first step, but the result must be interpreted in the context of the specific power station.
What Hidden Loads Could Be Draining the Battery?
If your portable power station keeps losing charge while the display shows 0 W, check connected devices and accessories before assuming the battery or power station is faulty. A small load may not appear clearly on the display, and a device can continue drawing power even when it seems idle.
Start by checking the AC outlets, USB ports, DC outputs, and accessories connected through adapters or extension cords. A 0 W reading may represent only the output currently being displayed, rather than every active output or the station’s total internal energy consumption.
Devices Connected to AC Outlets
Check the AC outlets first, particularly if you use your power station to run household appliances, electronics, or chargers.
Look for:
Chargers and power adapters: A phone, laptop, or other device may continue drawing power while connected, depending on its charging state and the adapter’s design.
Electronics in standby mode: Some devices consume electricity while plugged in, even when they are not actively being used.
Appliances with intermittent operation: A refrigerator, fan, or other appliance may cycle on and off, causing its power consumption to vary over time.
Forgotten connections: Plugs behind the power station, furniture, or other equipment can be easy to overlook.
Disconnecting an AC device completely helps determine whether it may be contributing to the drain. A connected device may also draw power through an enabled inverter even when its consumption is too small to register clearly on the display.
USB and DC Outputs
Do not check only the AC outlets. USB and DC outputs can supply external devices independently of the AC output, so a 0 W AC reading does not necessarily mean that no energy is leaving the power station.
Inspect the following:
USB ports: Phones, tablets, rechargeable accessories, and other USB-powered devices may draw power while connected.
12 V DC outlets: Compatible camping accessories and vehicle-powered equipment may remain connected and consume energy.
DC barrel connectors and proprietary output ports: Small devices and accessories can be easy to overlook, especially when cables run behind furniture or equipment.
Enabled output ports: Depending on the model, an enabled output may contribute to operating consumption even when no obvious external load is connected.
Disconnect devices from USB and DC ports when checking for possible external loads. If your power station has separate controls for these outputs, switch off unused outputs when appropriate.
Check the manual to understand which outputs are represented by the display and whether the station reports individual loads or combined output power.
Cables, Adapters, and Accessories
The entire connected setup matters—not just the main appliance. A power station may supply a multiport USB charger, a DC adapter, a USB hub, an extension cord, or a power strip with several devices attached. Some connected electronics and adapters may consume energy even when the final device appears inactive.
Inspect the connections between the power station and the devices, including:
Multiport chargers and USB hubs.
DC adapters and conversion cables.
Extension cords and power strips with connected equipment.
Accessories left plugged in after use.
Devices connected through intermediate adapters or distribution equipment.
An adapter or cable does not necessarily consume significant power simply because it is connected. Actual consumption depends on the equipment and its operating conditions. Check these connections to identify possible sources of external demand rather than assuming every accessory is responsible for measurable battery drain.
Use only cables and adapters approved for the relevant outputs. Never force incompatible connectors or bypass the power station’s electrical protections.
Common External Loads: What to Check
| Possible external load | What to inspect | What it may indicate |
|---|---|---|
| AC-connected charger or appliance | Check whether it remains plugged in or operates intermittently. | The device may draw power while connected or operating. |
| Electronics in standby mode | Check devices that remain connected but appear inactive. | Standby consumption may contribute to the load. |
| USB-connected device | Inspect USB ports and connected electronics. | A device may draw power through USB even when the AC output reads 0 W. |
| Equipment connected to a DC outlet | Check 12 V outlets, barrel connectors, and other DC ports. | The connected equipment may contribute to energy use. |
| Multiport charger, adapter, or hub | Inspect accessories and any downstream devices. | The accessory or connected equipment may draw power. |
| Several connected devices | Check the full setup, including extension cords and power strips. | More than one external load may contribute to the observed drain. |
Practical takeaway: Check every output, connected device, cable, and accessory before concluding that the power station has a fault. If the battery continues losing charge after external devices have been disconnected, internal operating consumption or other model-specific behavior may be involved.
How to Find the Cause of Battery Drain: Step-by-Step
Follow these steps to check whether connected devices, inverter standby consumption, or other operating conditions may be contributing to battery drain while your power station displays 0 W.
Step 1: Record the Initial Conditions
Record the starting battery percentage, displayed output, elapsed time, enabled outputs, and connected devices. Note whether the station is powered on and whether the AC inverter is enabled.
Step 2: Disconnect External Devices
Disconnect all devices and accessories from the AC, USB, and DC outputs. Keep the station in the same operating state and observe whether the battery percentage changes.
Step 3: Test Suspected Loads Individually
Reconnect one device at a time, beginning with the most likely source of drain. Note any changes in displayed watts and battery percentage over a suitable observation period.
Step 4: Compare AC Inverter States
If permitted by the manufacturer, compare battery drain with AC output enabled and disabled. Keep other settings and test conditions as similar as possible. Greater drain with AC enabled may indicate inverter standby consumption, but it does not establish the exact amount used by the inverter.
Step 5: Compare the Results
Compare the observations from each test, changing one variable at a time. Because battery-percentage readings are estimates, short tests may not reveal small differences.
Important: Follow the manufacturer’s instructions when disabling outputs or powering down the station. Test a fully powered-down state only if the model supports it and the manual permits it. Do not deliberately discharge the battery to a low level just to make a change easier to detect.
Test Log: Record Your Observations
Use this table to record the conditions and results of each test.
| Test | Operating state | Starting charge | Ending charge | Observation period |
|---|---|---|---|---|
| A | Station powered on, outputs enabled, no external devices | Record reading | Record reading | Record duration |
| B | Station powered on, outputs disabled | Record reading | Record reading | Use a comparable duration |
| C | Station fully powered down, if supported | Record reading | Record reading | Use a comparable duration |
Diagnostic Table: What to Check Next
Use the results to identify the most appropriate next step. These patterns suggest possible explanations; they do not confirm a specific fault.
| Observation | Possible interpretation | Next step |
|---|---|---|
| Battery charge decreases with AC enabled and external devices disconnected | Inverter standby consumption or other internal operating loads may contribute | Repeat the comparison with AC disabled, following the manufacturer’s instructions |
| Charge decreases with all outputs disabled while the station remains on | Internal operating consumption or model-specific behavior may remain | Check the manual for expected consumption; compare with a powered-down state if permitted |
| Charge decreases while the station is fully powered down | Self-discharge, SOC estimation, test conditions, or another issue may be involved | Verify the shutdown procedure and documented behavior; contact support if the loss remains unexplained |
| Battery percentage changes only slightly or inconsistently | The display may not resolve small changes over the test period | Repeat the test over a suitable period under comparable conditions |
| Drain appears only when a particular device is connected | The device or its connection path may contribute | Disconnect that device and repeat the comparison, where safe |
| The station displays an error or behaves unexpectedly | A model-specific condition or fault may require investigation | Record the error and follow the manufacturer’s troubleshooting instructions |
Practical takeaway: Start with external devices, then compare supported operating states. If the battery continues losing charge for no documented reason, contact the manufacturer rather than assuming that a specific component has failed.
How to Estimate Battery Drain From the Displayed Percentage
If your portable power station shows 0 W but its battery percentage decreases, you can use the change in state of charge (SOC) to estimate how much energy may have been lost. This calculation provides a rough indication of battery energy loss, even when the display does not show a useful output-power reading.
The result is an estimate, not a direct measurement of energy consumption. Its accuracy depends on the station’s nominal battery capacity, the SOC indicator, and the operating conditions during the observation period.
If you need help understanding battery capacity in watt-hours and amp-hours, use our battery capacity calculator to explore the relationship between these units.
Estimate Average Power Over Time
If you know how long the battery took to lose that percentage, you can estimate the average rate of energy use:
P_avg ≈ E_lost / t
Where:
P_avg is the estimated average power, in watts (W).
E_lost is the estimated energy loss, in watt-hours (Wh).
t is the observation period, in hours (h).
Continuing the example, suppose the displayed charge drops by 5 percentage points over 10 hours. Using the estimated energy loss of 50 Wh:
P_avg ≈ 50 Wh / 10 h ≈ 5 W
The estimated average power is about 5 W over the observation period.
This figure represents an approximate rate of battery energy loss, not necessarily the AC output power or the inverter’s standby consumption alone.
For a broader explanation of watts, watt-hours, and how to interpret energy-use calculations, see power consumption formulas explained with real-world examples.
Why This Is Only an Estimate
The calculation is useful for troubleshooting, but several limitations affect its accuracy.
Displayed SOC is approximate. The battery percentage is an estimate of the state of charge, not a direct measurement of energy flowing out of the battery. Small changes may be rounded or may not correspond to an exact amount of energy.
Rated capacity is not the same as usable energy. A battery’s nominal capacity does not guarantee that all its rated energy will be available at the outputs. Conversion losses, operating limits, battery management, and operating conditions can reduce the energy available to power connected devices. For a fuller explanation of how usable capacity affects operating time, see how long a power station lasts.
Operating state affects consumption. An enabled inverter, active USB or DC outputs, connected devices, and other internal functions may all contribute to battery drain.
Consumption may vary over time. An average calculated over several hours does not show whether energy use was constant or occurred intermittently.
The estimate does not identify the cause. A declining battery percentage cannot, by itself, distinguish between external loads, inverter standby consumption, other internal power use, or battery self-discharge.
For a more meaningful comparison, record the starting and ending SOC, elapsed time, and station operating state. Repeat the observation under comparable conditions, such as with external devices disconnected and unused outputs disabled. Consult the manufacturer’s documentation for model-specific information about battery capacity and power consumption.
Practical takeaway: A falling battery percentage can help estimate the scale of energy loss even when the display shows 0 W. Use the result to compare operating conditions and guide troubleshooting—not as an exact measurement of consumption or proof that a particular component is responsible.
If you want to calculate energy use for appliances and other electrical loads, explore our power consumption calculator and complete calculation guide.
Is the Battery Drain Normal or a Sign of a Problem?
Some battery drain may be expected while a portable power station is operating, even when no external devices appear to be drawing power. Internal electronics, an enabled AC inverter, and other model-specific functions may consume energy. However, persistent charge loss that the manufacturer’s documentation does not explain deserves further investigation.
There is no universal battery-percentage threshold that separates normal drain from a problem. Interpret the results in the context of your power station’s design, operating state, and documented specifications.
How to Interpret the Test Results
Use this table to assess the significance of your observations and decide what to do next. These are general indicators, not definitive diagnoses.
| Observation | Level of concern | Recommended action |
|---|---|---|
| Small or inconsistent percentage changes during a short test | Low, on its own | Repeat the observation over a suitable period under consistent conditions. A small fluctuation alone does not establish a fault. |
| Battery drain varies with the inverter or a connected device, or the display shows 0 W while a device continues operating | Needs verification | Check the manufacturer’s documentation for expected standby consumption and display behavior. Confirm whether the observed pattern matches the model’s specifications. |
| Charge loss remains unexplained under comparable conditions, especially when external devices are disconnected and relevant outputs are disabled | Further investigation warranted | Review the manufacturer’s troubleshooting guidance and contact support if the behavior persists or differs from documented specifications. |
| Battery percentage decreases while the station is fully powered down, contrary to the manufacturer’s documented behavior | Further investigation warranted | Verify that the shutdown procedure and test conditions were correct, then contact manufacturer support if the loss remains unexplained. |
When to Contact the Manufacturer
Contact the manufacturer if unexplained battery drain persists after the recommended checks, particularly if the station’s behavior differs from its published specifications or the battery percentage changes unexpectedly during comparable tests.
If the issue also includes unexpected shutdowns while powering equipment, see our guide to why a portable power station shuts off under load.
Before contacting support, record the exact model, starting and ending battery percentages, test duration, enabled outputs, connected devices, and any error messages. Do not open the power station or attempt internal battery or inverter repairs.
Practical takeaway: A 0 W reading alone does not establish whether battery drain is normal. The more useful question is whether the observed behavior is consistent with the manufacturer’s specifications. If charge loss remains unexplained after reasonable checks, contact the manufacturer rather than assuming a specific component has failed.
Safety Checks Before Troubleshooting
Before investigating battery drain, follow these basic precautions to protect yourself and your equipment.
Follow the model-specific manual. Use the manufacturer’s instructions for switching outputs on and off, powering down the station, and performing diagnostic checks.
Protect critical equipment. Do not disconnect a power station if doing so would interrupt essential equipment unless a safe alternative power source is available.
Use compatible cables and accessories. Check that connected equipment and adapters are approved for the relevant outputs and operating limits.
Do not open the enclosure or bypass protection systems. Never attempt to access internal battery components or disable the station’s built-in electrical protections.
Stop using a damaged unit. If you notice battery swelling, physical damage, unusual heat, or an abnormal smell, stop using the station if it is safe to do so and follow the manufacturer’s safety guidance. Do not charge or operate a potentially damaged unit.
Contact manufacturer support if a fault is suspected. If battery drain remains unexplained or the station displays an error, follow the model-specific troubleshooting instructions rather than attempting an internal repair.
Before continuing: Proceed only with checks that the manufacturer permits users to perform. If you suspect battery damage or another electrical fault, prioritize safety over further testing.
Frequently Asked Questions
Can a power station supply power to a device while its display shows 0 W?
Yes. A portable power station may continue supplying power to a connected device even when its display reads 0 W. Some displays do not register very small loads or may round low output values down to zero. The device may still be operating, so a 0 W reading does not necessarily mean that no energy is being used. Display thresholds and measurement behavior vary by model.
Why does my power station’s battery percentage suddenly drop?
A sudden drop in battery percentage can result from changes in the station’s state-of-charge estimate, fluctuations in power demand, or energy used by loads that are not fully reflected in the displayed output. Internal consumption, including AC inverter standby power when enabled, may also contribute. If the percentage continues to fall rapidly with all external devices disconnected, check the manufacturer’s troubleshooting guidance and contact support if the behavior persists.
Can the battery percentage be inaccurate even when the power station is working normally?
Yes. The displayed battery percentage is an estimate of the remaining charge, not a direct measurement of usable energy. Small changes in the estimate, battery conditions, and the station’s measurement or calibration behavior can cause the percentage to fluctuate or change unevenly. Compare readings over a consistent period and under similar operating conditions rather than relying on a single percentage change. Follow the manufacturer’s instructions if recalibration is recommended for your model.
Does using a USB or DC output affect battery drain when the AC display reads 0 W?
Yes. USB and DC devices can draw energy independently of the AC output. If the display shows only AC output, or does not clearly show the combined load, a 0 W AC reading may not reflect power being drawn through USB or DC ports. Disconnect all external devices and accessories, then test the outputs individually to identify whether a connected load is contributing to the battery drain. Check your model’s manual to understand what its display measures.
What information should I record before contacting power station support?
Record the power station’s exact model, firmware version if available, starting and ending battery percentages, and the time elapsed between readings. Note whether the unit was fully powered on, whether the AC inverter was enabled, which USB, DC, or AC devices were connected, and what the display showed. If possible, repeat the observation with all external devices disconnected and compare the results with the inverter on and off, following the manual. Also record any warning codes, unusual heat, noises, or other abnormal behavior. This information can help support distinguish normal standby consumption, a display or battery-estimation issue, and a possible fault.
Conclusion: What to Check First
If your portable power station shows 0 W but the battery percentage keeps dropping, do not assume the battery is faulty. First, identify the operating conditions associated with the charge loss.
Disconnect external devices. Check AC, USB, and DC connections for overlooked loads.
Check enabled outputs and the AC inverter. Follow the manufacturer’s instructions to disable unused outputs and compare the station’s behavior under different supported operating states.
Record and compare the results. Note the battery percentage, observation period, displayed watts, and operating state. Interpret small changes cautiously.
Contact manufacturer support if the drain remains unexplained. Compare your observations with the documentation for your exact model and report any persistent differences.
The goal is to identify what conditions are associated with the battery drain before deciding on repairs or replacement. Unexplained charge loss does not, by itself, prove that the battery has failed.