Om genopladelige batterier og Lithium batterier især.

Batteriets historie

Batterityper og karakteristika

Eksempler på batterier og deres egenskaber

Eksempler på batterier og deres egenskaber

LiPo celler fra BattMann

Udvalg fra El-flight

Sammenkobling af celler 2p3s 3s2p

Brug af balancere B B B 2p3s B B B 3s2p B B B

Opbevaring af LiPo celler

Eksempler på opladere

Opladningsforløb af LiPo Increasing the charge current on a lithium/ion charger does not shorten the charge time by much. Although the voltage peak is reached quicker with higher current, the topping charge will take longer.

Er LiPo batterier farlige ? Ja, det er de. De kan brænde og eksplodere. Ved overopladning, hvor gastrykket i cellerne stiger til over 10 Bar. Ved underafladning, hvor der kan afsættes kobber på anoden og cellen kan kortslutte. Ved overbelastning hvor temperaturen og gastryk stiger. Men det samme gælder faktisk NiCd og NiMh.

Sikkerhedsregler Oplad altid batterier under observation. Ikke i bilen og ikke om natten. Check altid at opladeren er indstillet korrekt Lad ikke med mere end 1C Undgå kortslutninger Overbelast ikke batteriet Hold batteriets celler i balance. Oplad med LiIon-programmet hvis du er i tvivl. Beskyt batteriet mod fysisk overlast

LiPo i daglig brug Lad være med at flyve batteriet helt tomt. Det forkorter levetiden. Aflad kun ca. 70%. Er batteriet blevet afladet for meget, så lad det straks op igen. Oplad eller aflad til 3,8V pr. celle før batteriet lægges væk i længere tid. Lad helst kun op med 1C. Det går som regel godt at lade med 2C, men levetiden forkortes og der spares kun lidt opladningstid. Du kan spare ladetid ved kun at oplade til 4,1V pr. celle. Flyvetiden forkortes kun lidt. Lad op mellem flyvningerne selv om batteriet ikke er tomt. Det har godt af det. Balancer batteriet jævnligt eller brug balancere under opladning.

NiCd batterier Advantages Fast and simple charge, even after prolonged storage. High number of charge/discharge cycles - if properly maintained, nickel-cadmium provides over 1000 charge/discharge cycles. Good load performance - nickel-cadmium allows recharging at low temperatures. Long shelf life - five-year storage is possible. Some priming prior to use will be required. Simple storage and transportation - most airfreight companies accept nickel-cadmium without special conditions. Good low temperature performance. Forgiving if abused - nickel-cadmium is one of the most rugged rechargeable batteries. Economically priced - nickel-cadmium is lowest in terms of cost per cycle. Available in a wide range of sizes and performance options - most nickel-cadmium cells are cylindrical. Limitations Relatively low energy density. Memory effect - nickel-cadmium must periodically be exercised (discharge/charge) to prevent memory. Environmentally unfriendly - nickel-cadmium contains toxic metals. Some countries restrict its use. Relatively high self-discharge - needs recharging after storage

NiMh batterier Advantages 30-40% higher capacity than standard nickel-cadmium. Nickel-metal-hydride has potential for yet higher energy densities. Less prone to memory than nickel-cadmium - fewer exercise cycles are required. Simple storage and transportation - transport is not subject to regulatory control. Environmentally friendly - contains only mild toxins; profitable for recycling. Limited service life - the performance starts to deteriorate after 200-300 cycles if repeatedly deeply cycled. Limitations Relatively short storage of three years. Cool temperature and a partial charge slows aging. Limited discharge current - although nickel-metal-hydride is capable of delivering high discharge currents, heavy load reduces the battery's cycle life. More complex charge algorithm needed - nickel-metal-hydride generates more heat during charge and requires slightly longer charge times than nickel-cadmium. Trickle charge settings are critical because the battery cannot absorb overcharge. High self-discharge - typically 50% higher than nickel-cadmium. Performance degrades if stored at elevated temperatures - nickel-metal-hydride should be stored in a cool place at 40% state-of-charge. High maintenance - nickel-metal hydride requires regular full discharge to prevent crystalline formation. nickel-cadmium should be exercised once a month, nickel-metal-hydride once in every 3 months.

LiIon batterier Advantages High energy density - potential for yet higher capacities. Does not need prolonged priming when new. One regular charge is all that's needed. Relatively low self-discharge - self-discharge is less than half that of nickel-based batteries. Low Maintenance - no periodic discharge is needed; there is no memory. Specialty cells can provide very high current to applications such as power tools. Limitations Requires protection circuit to maintain voltage and current within safe limits. Subject to aging, even if not in use - storage in a cool place at 40% charge reduces the aging effect. Transportation restrictions - shipment of larger quantities may be subject to regulatory control. This restriction does not apply to personal carry-on batteries. (See last section) Expensive to manufacture - about 40 percent higher in cost than nickel-cadmium. Not fully mature - metals and chemicals are changing on a continuing basis.

LiPo batterier Advantages Very low profile - batteries resembling the profile of a credit card are feasible. Flexible form factor - manufacturers are not bound by standard cell formats. With high volume, any reasonable size can be produced economically. Lightweight - gelled electrolytes enable simplified packaging by eliminating the metal shell. Improved safety - more resistant to overcharge; less chance for electrolyte leakage. Limitations Lower energy density and decreased cycle count compared to lithium-ion. Expensive to manufacture. No standard sizes. Most cells are produced for high volume consumer markets. Higher cost-to-energy ratio than lithium-ion