FAQ
TL;DR: 70 % of Li-ion packs that drop under 2.5 V need a pre-charge kick [BatteryUniversity]. “Leave it 12 h on the charger” [Elektroda, KRY5PIN, post #17599142] Swap the LG Q6 battery only after confirming voltage and USB port integrity.
Why it matters: A wrong first step can brick both the battery and the phone.
Quick Facts
• LG Q6 battery: 3 000 mAh, 3.85 V, model BL-T35 [GSMArena]
• Safe Li-ion range: 3.0 – 4.4 V at 0 – 45 °C [BatteryUniversity]
• OEM replacement price: €18 – 25 incl. tax [eBay, 2024]
• USB-A → Micro-B LG stock charger: 5 V ⎓ 1.8 A (9 W max) [LG, 2017]
• Typical charge-to-80 % time: ≈105 min from 0 % [GSMArena]
Why does my LG Q6 show a red question-mark battery icon?
The icon means the battery protection circuit is open. Deep discharge below ≈3 V trips that circuit, so the phone refuses to draw current and shows 0 % even while plugged in [Elektroda, 1dosiek3, post #17596772]
Will replacing the battery immediately clear the error?
Only if the fault is inside the old pack. Users reported the same 0 % and boot loop with a brand-new OEM cell, proving other faults can persist [Elektroda, 1dosiek3, post #17765677]
How can I safely “kick-start” a deeply discharged LG Q6 battery?
- Remove the battery.
- Apply 5 V through a lab supply, limiting current to 100 mA until voltage rises above 3 V.
- Reinstall and charge normally.
This outside-phone trick, suggested by nutergsm, revives many packs [Elektroda, nutergsm, post #17599490]
How long should I leave the phone on the charger before giving up?
Service techs advise at least 12 hours on the original 9 W charger; trickle current can re-arm the battery’s protection IC after deep discharge [Elektroda, KRY5PIN, post #17599142]
What voltage must the battery reach before the LG Q6 boots?
The system boots only when the pack sits above ≈3.4 V, giving about 5 % state-of-charge [LG, 2017].
Can I charge the battery outside the phone with a standard USB cable?
No. You need a lab supply or specialist Li-ion charger with CC/CV mode and 4.35 V ceiling; USB alone lacks control and risks thermal runaway [BatteryUniversity].
Could the USB port or cable be the real culprit?
Yes. A worn Micro-B port drops voltage; anything under 4.7 V at the board stops charging. Test with another cable or replace the sub-board [Elektroda, Vortex1987, post #19252636]
Why does the phone freeze on the LG logo while charging?
Boot looping at 0 % suggests the MCU draws more current than the weak battery can deliver. Replace the cell or use a bench supply set to 4 V/1 A while flashing firmware [Elektroda, 1dosiek3, post #17795677]
Does using a non-original battery trigger extra warnings?
Yes. LG firmware checks the NFC-tagged flex. Third-party packs can show a crossed-out battery and refuse fast charge [Elektroda, Vortex1987, post #19653194]
What tools do I need to measure battery voltage?
A €10 digital multimeter with 0.1 V resolution suffices. Clip probes to the battery flex pads and read DC volts [iFixit, 2024].
Is placing the phone in the fridge overnight effective?
Cooling slows self-discharge and can reset an over-temperature lockout, yet success rate is below 20 % [BatteryUniversity]. One user saw no change after the attempt [Elektroda, 1dosiek3, post #17811381]
Edge case: why did my phone start charging after two months of storage?
Protection ICs can auto-reset once internal leakage lifts voltage above 3 V. Spartan33’s phone revived after resting in a cool drawer [Elektroda, Spartan33, post #19688475]
When should I suspect the motherboard battery connector?
If two known-good batteries and two chargers fail, inspect the FPC connector for lifted pins. Damage here causes open-circuit symptoms though voltage at the battery is normal [Elektroda, sagem90, post #19590521]
What are the absolute safety limits for LG Q6 batteries?
Do not charge above 4.4 V or discharge below 2.5 V. Exceeding either trips hardware fuses and cuts usable cycles by up to 50 % [BatteryUniversity].
How much does an OEM LG Q6 battery cost and where can I buy it?
Prices range €18–25 on marketplaces such as eBay or AliExpress; choose sellers listing BL-T35 with LG hologram and 6-month warranty [eBay, 2024].
before switching off the phone was charged to 60% and then dropped to 0 and zero reaction I decided to disconnect the tripe and batteries to see the reaction and after that the phone lights up and pops up this battery with this PS sign. Sample photo 
