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FAQ2019-11-26T19:05:08+00:00
How to match cells for a battery pack before assembling the pack2019-11-24T04:50:05+00:00

Coremax will do the following things before assembling the pack:

  •  Select capacity, same capacities cells for one pack
  •  Measure the voltage, same voltage cells for one pack(difference is under 0.02v per cell)
  •  Check and Measure the internal resistance, same IR cells for one pack (difference is under 1m Ohm)

All above steps are very strict to make sure the pack performance is perfect.

what is lithium iron phosphate battery2019-11-22T14:33:55+00:00

What is a lithium iron phosphate battery?

lithium iron phosphate battery is also a rechargeable type of battery but made with lithium iron phosphate (LiFePO4) as the cathode material.

While lithium-iron is a newer version in the lithium battery family, its anodes are also made up of carbon in batteries.

Phosphate based technology possesses superior thermal and chemical stability which provides better safety characteristics than those of Lithium-ion technology made with other cathode materials. Lithium phosphate cells are incombustible in the event of mishandling during charge or discharge, they are more stable under overcharge or short circuit conditions and they can withstand high temperatures without decomposing. When abuse does occur, the phosphate based cathode material will not burn and is not prone to thermal runaway. Phosphate chemistry also offers a longer cycle life.

byd lithium iron phosphate battery

lithium iron phosphate battery

The lithium-iron (LiFePo4) battery has a slight edge over the Li-ion (LiCoO2) battery for safety. This is important because a battery should not get overheated or catch fire in case of overcharging.

The lithium-iron battery has superior chemical and thermal stability. A Lithium-iron battery remains cool at room temperature while the Li-ion may suffer thermal runaway and heats up faster under similar charging conditions.

LiFePO4 is a nontoxic material, but LiCoO2 is hazardous in nature, so is not considered a safe material. Disposal of Li-ion battery is a big concern for the manufacturer and user. .

100ah lithium iron phosphate battery
How to make a 12 volt rechargeable lithium battery pack2019-11-20T06:31:35+00:00

Make a 12 volt rechargeable lithium battery pack

Rechargeable lithium batteries produce 3.7 or 3.2 volts, depending on the type of battery and the chemicals it uses. To make batteries with higher voltages, manufacturers link identical batteries in a series circuit. In this way the voltages of the individual batteries are added together, so three 3.7-volt battery cells become one 12-volt battery (3.7x 3 = 11.1 volt). You can use the same electrical technique to create your own battery packs at home. Doing so requires basic math and no electronic skills.

Select the type of batteries from which to create a 12 volt rechargeable lithium battery pack. You might consider their size, shape or amp/hour capacity to be important, or you may just choose the batteries readily available where you live. It is important to use identical batteries in your pack. They must all have the same voltage and current characteristics.

Calculate how many batteries you need by dividing 12 by the voltage of the batteries.

Link together the batteries, connecting the positive terminal of the first battery to the negative terminal of the second. Link all the batteries in the same way, always joining opposite polarity terminals. You can stack cylindrical batteries, such as the A, C and D series batteries, on top of each other in a plastic or cardboard tube, or wrap them together in sticking tape. When using larger batteries with spring terminals, such as rectangular 6-volt batteries, join them with short lengths of wire.

Run a wire from the unused terminals at each end of the line of batteries. The voltage between the two wires is 12 volts.

If you want DIY for fan, Welcome to discuss and get help from Coremax Technical team. If you are looking for a professional 12 volt rechargeable lithium battery pack, please send business inquiry to Coremax. We are glad to offer all in one solution for you.

custom li ion battery pack
IFR32650 solar light batteries
how to charge a 12 volt lithium battery2019-11-20T06:21:09+00:00

First check what kind of lithium battery you have. There are major 2 type of lithium battery in the market. 3.7v cell and 3.2v cell. And find out the full charge voltage. If the cell is 3.7v. Nomally full charge voltage is 12.6v( 3S lithium ion battery. when fully charged, each cell 4.2 volt). While if it is 3.2v cell. When it fully charged, the voltage is 3.65 volt. 12 volt lithium battery pack fully charged is 14.6 volt.( 4S 3.2 v cell). Make sure your charger voltage is compatable with the 12v lithium battery.

Please note that not all Li-ion batteries charge to the voltage threshold of 4.20V/cell. Lithium iron phosphate typically charges to the cut-off voltage of 3.65V/cell and lithium-titanate to 2.85V/cell. Some Energy Cells may accept 4.30V/cell and higher. It is important to observe these voltage limits.

Important to Lithium battery chargers

Lithium cells (18650, lipos, LiFePo4 etc.) which require the charging cycle CC-CV (constant current, constant voltage). The battery system may work for other types for batteries as well, as long as they wants to be charged with CCCV.

CC-CV varies the voltage to constantly deliver the current set by you. When the voltage reaches the battery’s maximum charge voltage, the current is gradually decreased so that the voltage does not exceed the set value.

3.2 volt solar batteries 16850

3.2v LiFePo4 cells

sony 21700

3.7v Lithium ion cells

Lithium battery Charger guide List

Nominal Voltage Battery type series Charging voltage
12v 3.7v lithium ion 3 12.6v
3.2v LiFePo4 4 14.6v
24v 3.7v lithium ion 7 29.4v
3.2v LiFePo4 8 29.2v
36v 3.7v lithium ion 10 42v
3.7v lithium ion 11 46.2v
3.2v LiFePo4 11 40.15v
3.2v LiFePo4 12 43.8v
48v 3.7v lithium ion 13 54.6v
3.7v lithium ion 14 58.8v
3.2v LiFePo4 15 54.8v
3.2v LiFePo4 16 58.4v
60v 3.7v lithium ion 17 71.4v
3.2v LiFePo4 20 73v
72v 3.7v lithium ion 20 84v
3.2v LiFePo4 24 87.6v

Certification:

Our prismatic cells already pass UL, MSDS, UN38.3, CE. These certification are available without ask customer to pay additional certification cost.

Shipping of Lithium Batteries:

Since our battery cells all passes MSDS, UN38.3 . And also we We can hold shipping documents.Ship our batteries by Air flight or by sea all is acceptable.

 

Warranty:

We provide 8 years for our batteries cells. 5 years for our battery packs. The warranty is only available for professional customer’s. Custom who without lithium battery knowledge and abuse with the batteries will be limited on warranty period.