FAQ

Reason: Increase in the number of cycles, high temperature / overcharging leading to loss of active substance.

Overcharging: gas production and thermal runaway are possible (the risk is lower than that of ternary batteries).
Over-discharge: internal resistance increases, irreversible loss of capacity.
Protection: depends on BMS control voltage (2.0-3.65V).

Cause: SEI film thickening, material pulverisation.
Suggestion: Avoid high rate charging and discharging, control the working temperature (25-40℃).

Advantage: high thermal stability (decomposition temperature 800°C), not easy to explode.
Risk: Short circuit may cause fire, need to be equipped with thermal management system.

Normal range: Slight heating (≤45℃).
Abnormal: High temperature (>60℃) need to check the internal resistance or contact problem.

Both are how the battery is connected and is something you have to learn when assembling the battery.
Series connection: Connecting the positive pole of one battery to the negative pole of another
battery increases the voltage of the battery pack, but the capacity remains the same.
Parallel connection: Connecting the positive pole of one battery to the positive pole of another
battery increases the capacity of the battery pack, but the voltage remains the same.

After receiving the battery, please immediately check whether the insulating layer of the battery (usually a blue film) is damaged and whether the QR code is scratched. Also use a multimeter to check the voltage/internal resistance/capacity. Be sure to charge the battery to full voltage before using it for the first time.

● Grade A: Cells perform to manufacturer specifications.
● Grade B: Cells under-perform or have other defects.
● Grade C: Cells are used, repackaged, salvaged, or damaged.

Performance: About 70% of capacity at 0℃, down to below 50% at -20℃.
Suggestion: Limit the current (≤0.5C) for low temperature charging, and match with heat preservation measures.

Reason: Internal gas production (moisture contamination, overcharging, high temperature).
Solution: Strict sealing process, avoid extreme use conditions.

Impact: ‘Short board effect’ shortens the overall life.
Solution: grouping + active equalisation management.

Suggestions: storage voltage 3.0-3.5V, temperature 20-25℃, regular inspection.
Prohibition: Full-charged storage is likely to accelerate the decay.

Current situation: high recycling cost, mainstream solid-phase regeneration method.
Tips: Contact professional organisations, avoid dismantling by yourself.

There is no doubt that LiFePO4 batteries are one of the safest lithium-ion batteries out there. Due to its chemical properties and safe internal structure, LiFePO4 batteries will not explode even if they are severely damaged (such as puncture/strong knocks).

The most important thing is the temperature. LiFePO4 batteries are well stored at room temperature (15°C~25°C), but too low temperature may damage the battery. In an icy environment, you need to pay attention to the insulation of the battery. Alternatively, the battery can be stored in a dry and ventilated room at 50% SOC.

LFP batteries and NMC batteries are both lithium-ion batteries, but the chemical properties are somewhat different.

LFP battery: The nominal voltage of the single unit is 3.2V, high safety and many cycles. The energy density is slightly weaker, suitable for energy storage projects and DIY projects.

NMC battery: The nominal voltage of the single unit is 3.7V, the safety is slightly weaker and the number of cycles is relatively small. High energy density, suitable for use as power batteries (such as electric vehicles).

Further reading: LFP Battery VS NMC Battery

Advantage of LFP: high thermal stability (decomposition temperature 800℃ vs. 200℃ for Li-ion ternary), not easy to explode by pinprick, suitable for energy storage/electric vehicles. Risks of LiPoC: overcharging is easy to thermal runaway, need strict BMS protection.

LFP: -20℃ retains less than 50% of its capacity, charging needs to be limited by current.
LFP: -20℃ capacity retains 70%, better low-temperature performance, but poor high-temperature stability.

LFP: supports high rate charging (common for 3C fast charging), 30 minutes to 80%.
NiMH battery: slow charging (0.5C mainly), easy to overcharge and get hot.

LFP: high temperature resistance (normal operation under 60℃), slow decay at high temperature.
Lead-acid battery: easy to self-discharge at high temperature, electrolyte evaporates quickly, shortening the life span.

Reason for recommendation: long life, high safety, support deep discharge (up to 20%), better than lead-acid (only up to 50%).
Disadvantage: heating equipment is needed in low temperature areas.

LFP batteries are lithium-ion batteries, while AGM batteries are lead-acid batteries. The difference between the two is huge.

LFP battery: The nominal voltage of the single unit is 3.2V, with high safety and many cycles. Higher energy density than AGM batteries, suitable for energy storage projects and DIY projects. To a large extent, it is an upgrade of the AGM battery.

AGM battery: The nominal voltage of the single unit is 2.1V, the safety is general and the number of cycles is small. It has low energy density and is also suitable for energy storage projects. The advantage is that it is very cheap and can be bought everywhere.

Further reading: LFP Battery VS AGM Battery

Cycle times: LFP is about 2000-5000 cycles (80% capacity) vs. 300-500 cycles for lead-acid.
Lifespan: LFP can be used for 5-10 years vs Lead Acid 1-3 years.

Energy density: LFP 120-160Wh/kg vs. 200-260Wh/kg for Li-ion, heavier weight.
Advantage: Lead-acid batteries are 2-3 times heavier than LFP, and LFP is smaller.

Material cost: LFP (Iron) vs Li-ion (Cobalt, Nickel), LFP cost is 30%-50% lower.
Long-term cost-effectiveness: LFP has a longer lifespan and lower overall cost.

LFP: no heavy metal pollution, recyclable but complicated process.
Lead-acid battery: lead pollution, mature recycling system, but need to prevent leakage.

Definition: Battery Management System (BMS).
Core function:Prevent overcharge / overdischarge / overcurrent
Equalisation of individual voltages (prolonging the life of the battery pack)
Monitoring of temperature, charge level (SOC)

Symptoms: Battery pack is not fully charged or cut off prematurely
Large single-unit voltage difference (>50mV)
Display reports errors (e.g. ‘overvoltage’ ‘short circuit’)
Balancer does not work (no heat generation / indicator does not light up)

Recommended: Check individual voltage differentials every 6 months.
Clean dust and ensure good heat dissipation Disconnect the battery when not in use for a long time

Functional limitation: Can slow down the battery decay, but can not repair the physical damage (e.g., the pole plate falls off)
Excessively degraded batteries (<60% capacity) need to be replaced and cannot be saved by the BMS.

Design life: 5-8 years (matching with battery life).
Lifespan shortening factors: high temperature, humidity, frequent high current discharge.

Reason: Poor consistency of battery cells (different voltage / capacity) leads to ‘short board effect’.
Role: Through active / passive equalisation, reduce the single cell voltage difference (ideally <5mV) and improve battery pack performance.

Key parameters: Voltage / Current: Matching battery pack voltage (e.g. 12V/24V) and maximum discharge current
Equalisation: Active equalisation (high efficiency, high cost) vs passive equalisation (resistive energy consumption)
Communication function: Support CAN bus / LCD display is better.

Troubleshooting steps: Check whether the power supply is normal (BMS supply voltage ≥ 9V)
Whether the voltage of the single unit exceeds the equalisation threshold (e.g. > 3.45V triggers equalisation)
Replace the damaged equalisation module (use a multimeter to measure whether the resistance is broken).

Yes:
LFP battery: charge/discharge cut-off voltage 3.65V/2.0V
Li-ion ternary battery: cut-off voltage 4.2V/2.5V
Lead-acid batteries: cut-off voltage 14.4V/10.5V
Risk of mixing: over-charging and over-discharging damage the battery

Self-consumption: Standby power consumption <10mA (high quality BMS)
Passive equalisation consumes about 1-3W (when equalising)
Impact: Disconnecting the BMS power supply is recommended for long term storage.