Custom Lithium Ion / Polymer

Batterypowerz is a manufacturer of custom lithium ion (Li-Ion) battery packs and assemblies, as well as custom lithium polymer battery packs and assemblies. Our lithium battery design team uses the latest mechanical and electronic design tools to optimize the reliability, safety and manufacturability of your custom battery packs. This gives you the most cost effective and dependable lithium ion / polymer battery pack solution for your specific needs.

View individual product specifications for individual Lithium Ion / Lithium Polymer batteries.

Custom Lithium Ion Battery Packs (Li-Ion Batteries)

Lithium Ion (Li-ion) is an advanced technology that offers increased performance over nickel and lead based chemistries at a price premium for custom battery packs and battery assemblies. Li-ion and Lithium Polymer can have twice the energy density of NiCd, can be capable of high discharge currents, and has relatively low self-discharge.

There are several major types of Lithium Ion. Lithium Cobalt Oxide offers the best energy density. Lithium Manganese offers greater safety with lower energy density than lithium cobalt oxide. Lithium Iron Phosphate offers the high discharge rate capability as well as long cycle and calendar life. Some manufacturers offer mixed cathodes to optimize specific performance characteristics in lithium rechargeable cells.

Due to Lithium Ion’s high energy density and the inherent volatility of lithium as an element, each battery pack, and also single cells, require a special control circuit to manage their upper and lower voltage thresholds and to keep operating current and temperature within acceptable limits during charge and discharge.

Lithium Ion battery technology is under constant improvement. New electrode materials promise improved capacity and better manufacturing techniques will continue to bring the price of Lithium Ion cells down, perhaps considerably.

The Lithium Ion charge circuit is generally a two-stage constant current/constant voltage design. A fully discharged cell will take a constant current charge at a 1C rate (one times rated capacity) until it reaches a set voltage of between 3.6 volts and 4.2 volts, depending on the specific chemsitry, which takes about one hour. Then, the charger switches to constant voltage, and the current tapers off until the battery is fully charged which takes about another two ours. The whole process takes about three hours, a fairly fast charge. Also Lithium Ion batteries may be removed from charge before fully charged with no side effects. Lithium Ion will not tolerate overcharge conditions and therefore cannot be trickle charged.

• Cell Voltage: 3.2V – 3.7V (nominal)
• Capacity: 500mAh to 5000mAh
• Energy by Weight: 105 Wh/kg to 130 Wh/kg
• Energy by Volume: 270 Wh/L to 325 Wh/L
• Discharge Characteristics: (recommended drain mA to amperes)
• Cycle Life: Over 300 - 1000 Cycles
• Self Discharge: 10%/month
• Temperature Range: -20° C to +60° C
• Preferred Charge Methods: Constant Voltage/Constant Current
• Sizes: Various Cylindrical Cells and Prismatic Cells
• Applications: Medical, Military, Industrial, Consumer Electronics

Discharge Characteristics for a Typical Li-ion 18650 Cell	Discharge Vs. Temperature Characteristics for a Typical Li-ion 18650 Cell
High Rate Discharge Characteristics for a Typical Li-ion 18650 Cell	Voltage Vs. Current Discharge Characteristics for a Typical Li-ion 18650 Cell

Custom Lithium Polymer Battery Packs

Lithium-ion-polymer is not a unique and different chemistry than lithium-ion and only differs in construction. Li-polymer can be made in an assortment of chemistries and the most widely used format is Li-cobalt. The difference in construction over conventional li-ion cell, however, allows for very flexible packaging, lower cost, and safer operation. Cells as thin as credit card are possible. These factors contribute to make custom lithium polymer battery packs and battery assemblies increasingly attractive.

• Cell Voltage: 3.6V – 3.7V (nominal)
• Capacity: 500mAh to 3000mAh
• Energy by Weight: 120 Wh/kg
• Energy by Volume: 250 Wh/L
• Discharge Characteristics: (recommended drain mA to amperes)
• Cycle Life: More than 500 Cycles
• Self Discharge: N/A
• Temperature Range: -20° C to +60° C
• Preferred Charge Methods: Constant Current/Constant Voltage
• Sizes: N/A
• Applications: Audio visual equipment, Cellular phones, Office automation, Notebook PC's, PDA's, and handy terminals