4S BMS for Lithium Battery Pack – E-Bikes, Portable Electronics & Energy Storage

Wholesale Custom 4S BMS for Lithium Battery Pack Applications

Product Model: 4S BMS 14.8V Li ion Protection Module

Product Description:

The protection board is for 4S custom lithium battery pack, it can be used for Li-ion/Li-polymer batteries.
Stable various protective functions for charging and discharging, such as accurate overcharge protection, over-discharge protection, over current protection and short circuit protection.

High-Performance li-ion battery with custom solutions

Himax premium Li-ion batteries by Himax offer high energy density, long cycle life, and safe, reliable performance for various applications. We provide custom battery packs and bulk orders at competitive wholesale prices to meet your needs.

Technical Parameters:

Item		Custom Lithium Battery Pack BMS
Over charge protection	Over charge detection voltage	3.90V±0.025V
	Over charge detection delay time	1.0±0.5s
	Over charge release voltage	3.80V±0.05V
Over discharge pretection	Over discharge detection voltage	2.3±0.08V
	Over discharge detection delay time	100±50ms
	Over discharge release Voltage	2.7V±0.1V
	Rated operational current	≤10A
Over current protection	Over current detection current	30±5A
	Detection delay time	10±5ms
Short protection	Detection condition	Exterior short circuit
	Release condition	Cut short circuit
Resistance	Main loop electrify resistance	≤55mΩ
	Balanced differential pressure open voltage	≥30mV
	Balanced differential pressure off voltage	≤10mV
	Balanced current	Max: 95mA
Current consumption	Current consume in normal operation	50.0μA Max
Dimension (mm)	50 x 32 x 4mm

Features and Benefits

Apply for 4 cells li-ion / li-polymer batery pack protection
Internally trimmed charge and discharge voltage limits
Discharge current limit detection
Low current standby mode when cells are discharged
High quality and high yield: 100% tested before shipment
Dimension: 50 x 16 x 3.5 mm
Compatible with both Li-ion and Li-Polymer cells

B+：Connected to the fourth battery’s positive terminal
B3+：Connected to the third battery’s positive terminal
B2+：Connected to the second battery’s positive terminal
B1+：Connected to the first battery’s positive terminal
B-：Connected to the first battery’s negative terminal
P+：Connected to the battery’s output or the charger’s positive terminal
P-：Connected to the battery’s output or the charger’s negative terminal

Usage and Attention:

After purchasing the protection mold, users should connect lines in compliance with the instruction. Voltage usually exists in the battery, so operators should peel one line and then connect another starting from B-. Lines should be connected from the low position to the high position with no mistake of order, or the irreparable damage could be caused.
When lines get connected, bits of copper and tin should not cling to the guard shield.
Protection board should be connected to battery group with compliance to specifications and any leading line should not be put on the back of the board but on the lateral side.
When equipping the guard shield, hard epoxy sheer should be fixed on the back of the board as the barrier to prevent the squeezing against short circuit.
When welding output lines, power supply line with the proper diameter should be chosen to prevent great temperature rising and great dropping of line voltage while high current discharges.
The guard shield is usually fixed in the battery box, insulation, heat relief and tightness should be greatly concerned, or the internal short circuit could lead to some danger.
The full-charged battery group should be put properly out of children touch.
If any unusual condition appears during the using process, please stop using the product immediately.

FAQ

Generally, what are Lithium-Ion Batteries?
A. Lithium-ion batteries are rechargeable batteries in which lithium ions move from the anode to the cathode during discharging and back when charging. They are popular batteries for use in consumer electronics because they provide high energy density, possess no memory effect and have a slow loss of charge when not in use. These batteries come in a wide variety of shapes and sizes. Compared to lead-acid batteries, Lithium-ion batteries are lighter and provide a higher open circuit voltage, which allows for power transfer at lower currents. These batteries have the following characteristics:

Features of ionic Lithium-ion Deep Cycle Batteries:

Light weight, up to 80% less than a conventional, comparable energy storage lead-acid battery.
Lasts 300-400% longer than lead-acid.
Lower shelf discharge rate (2% vs. 5-8% /month).
Drop-in replacement for your OEM battery.
Expected 8-10 years of battery life.
No explosive gasses during charging, no acid spills.
Environmentally friendly, no lead or heavy metals.
Safe to operate!
The term “Lithium-ion” battery is a general term. There are many different chemistries for Lithium-Ion batteries including LiCoO2 (cylindrical cell), LiPo, and LiFePO4 (cylindrical/prismatic cell). Ionic mostly focuses on designing, manufacturing and marketing LiFePO4 batteries for its starter and deep cycle batteries.

What are LiFePO4 (Lithium Iron Phosphate) Batteries?
A. Lithium Iron Phosphate (LiFePO4) batteries provide several advantages over traditional Lithium-ion batteries based on LiCoO2 chemistry. LiFePO4 batteries provide much higher specific capacity, superior thermal and chemical stability, enhance safety, improve cost performance, enhanced charge and discharge rates, enhanced cycle life and come in a compact, lightweight package. LiFePO4 batteries an offer a cycle life of over 2,000 charge cycles!

Why should I get a ionic’s lithium-ion “Deep Cycle” energy storage battery?
A. Lithium-ion batteries provide multiple advantages over standard lead-acid batteries for energy storage use that we’ll outline below:

Substantially Lighter – Lithium-ion batteries are just a fraction of the weight of the original lead-acid battery.
More Powerful – Lithium-ion batteries operate at a higher voltage than standard lead-acid batteries, giving you faster engine speed for longer durations. Lead-acid batteries drop to just 12.5V when only 20% of the battery capacity is used, but lithium-ion batteries provide over 12.8V even when only 20% of the battery capacity is left.
Low Self-Discharge Rate– Lead-acid batteries lose 4%-25% of their charge every month depending on the quality of the plates and separators used. If you leave a vehicle unattended for a month, the lead-acid battery might lose too much power and the vehicle might not start. On the other hand, our lithium battery chemistry loses less than 3% of charge per month; you can go for several months without having to worry.
Environmental Friendly– Ionic batteries contain no toxic substances. There is no poisonous lead or corrosive sulfuric acid and as a result, no possible way for an explosive gassing event that is common with lead-acid batteries. In addition, there is no need to maintain acid levels or worry about venting like traditional lead-acid batteries do. The only maintenance that ionic batteries require is ensuring that the battery never drains beyond 80% to ensure optimal life.
Long Lasting– Cheap lead-acid batteries usually only last 1 to 2 years while gel and AGM lead-acid batteries last 3-5 years with proper maintenance. However, ionic’s lithium-ion batteries can provide 8-10 years of use, easily exceeding the life of any lead-acid battery. Battery life depends purely on proper operation and maintenance, so use common-sense and ensure the battery does not drain beyond 80% discharge. If you are replacing a lead-acid battery in two years or less due to deep cycling damage, you will save money in the long run moving to a ionic lithium-ion
Fast Recharging – ionic’s lithium-ion batteries can accept charge current at up to 5 times faster than a lead-acid battery. What’s more, the charge efficiency is about 75% for lead-acid in contrast to 97% for ionic’s lithium-ion battery. That means less energy is needed to charge and causes less strain on your alternator.

What advantages does ionic “Deep Cycle Batteries” have over other batteries?
A. ionic utilizes the latest advancements in lithium-ion battery technology along with custom features to provide you with the best battery for your vehicle:

Internal Cell Balancing Circuit – ionic batteries have a micro-processor controlled internal cell balancing board in each of its batteries designed to maximize the performance of each cell in the batteries.
Battery Management System (BMS) – ionic lithium-ion smart batteries contain a solid state switch that controls temperature volatility. This switch prevents overcharging and discharging, improving the overall lifespan performance and safety of the batteries.
Quality Engineering – ionic’s innovation laboratory prides itself on the design and construction of its batteries utilizing the highest quality components in all phases of design and construction. The ionic built-in intelligent components guarantee the safety and quality of each ionic product.
Prismatic Cells – Cylindrical cells only come in certain sizes which limits the possible shapes and sizes of the starter battery case designs. As such, batteries fit for many vehicles may be poor, or impossible as they are too wide or too tall and create internal hot spots. Ionic prismatic cells on the other hand, are rectangular packages which can be freely designed and sized according to the size requirements of the battery case. As such, ionic offers perfect drop-in fit in most vehicles along with having better thermal management properties.

How does ionic’s “Deep Cycle” capacity (Ah) rating compare to lead-acid Ah ratings?
A. Ionic’s “Deep Cycle” batteries have true lithium capacity rating at 1C discharge rate meaning a 12Ah “Deep Cycle” lithium-ion battery will be able to provide 12A for 1 hour. On the other hand, most lead-acid batteries have a 20hr or 25hr rating printed for its Ah capacity meaning the same 12Ah lead-acid battery discharging in 1 hour would typically only provide 6Ah of useable energy. Going below 50% DOD will damage a lead-acid battery, even if they claim to be a deep discharge battery. Thus a 12Ah lithium battery would perform closer to a 48Ah lead-acid battery rating for higher discharge currents and life performance.
Ionic’s lithium-ion batteries have 1/3 the internal resistance of a similar capacity lead-acid battery and they can be safely discharged to 90% DOD. Lead-acid internal resistance rises as they are discharged; the actual capacity which can be used may be as little as 20% of the mfg. rating. Discharging in excess will damage the lead-acid battery. Ionic’s lithium-ion batteries hold a higher voltage during discharge.

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Lithium Ion Battery Wholesale

Your Grade A Battery Supplier:

When purchasing wholesale Li-ion batteries from Himax, you’re guaranteed top-tier quality, reliability, and cost-effectiveness at every stage. Each Li-ion battery undergoes a rigorous pre-sale quality inspection before shipping. We apply strict standards to select only Li-ion cells that meet the highest performance, durability, and safety levels. This ensures that the Li-ion batteries you order are crafted from premium materials and undergo thorough testing to guarantee reliability.

At Himax, we specialize in custom Li-ion battery packs tailored to your exact specifications, providing solutions for industries like consumer electronics, renewable energy, and medical devices. Our advanced BMS technology offers robust protection against overcharging, short circuits, and overheating, ensuring safety and optimal performance. With bulk Li-ion battery orders, our custom solutions offer an affordable option that meets the demands of your business, while enhancing overall value with clear usage guidelines to maximize lifespan and efficiency.

For bulk buyers, Himax stands out among Li-ion battery suppliers by offering not only competitive wholesale pricing but also comprehensive after-sales support, including warranties and technical assistance. Whether you require custom battery designs or long-term service agreements, we are committed to delivering cost-effective, reliable solutions that perform flawlessly over time.

IMPORTANT: PRE-USE GUIDELINES

DO: Perform a Pre-Installation Check!

Ensure a thorough examination before installation:

Inspect Each Cell: Visually check for any damage, swelling, leaks, or missing accessories. Do not use a cell if the casing is pierced, leaking, cracked, or otherwise visibly damaged.
Clean the Terminals: Ensure bus bars, wire terminal lugs, and terminals are clean and free from corrosion or debris. This helps reduce resistance between the DC terminal and cable connection.
Test Voltage and Capacity: Use a multimeter to check each cell’s voltage and internal resistance, and a battery analyzer or specialized tester to confirm capacity.
Top Balance Before Use: Charge all cells to full voltage before assembling them. We recommend using chargers specifically designed for Li-ion cells.

DON’T:

Do Not Discharge Immediately After Delivery: Allow the battery to settle before use.
Do Not Mix Cells from Different Series: Even if they are the same type and capacity, avoid mixing cells from different manufacturing series or batches. Always use cells from the same batch.
Avoid Loose Terminal Connections: Ensure all terminals are securely fastened to prevent performance issues.