Lithium-ion battery, a secondary cell (battery), is composed of positive pole, negative pole,diaphragm, electrolyte. To charge-discharge, electrolyte infiltrated positive and negative pole, lithium-ion by the media---electrolyte inset and inlay between positive and negative poles. To avoid short circuit of positive-negative poles through electrolyte, they should be separated by diaphragm. When charging, lithium-ion, by electrolyte, is taking off from positive pole and embedding from negative pole , which is in rich lithium condition. When discharging, the situation is just the opposite. Battery, in general, uses Lithium materials in its poles, a represent of modern high-qualified battery.
Ni-MHbattery, a composition of hydrion and metallic nickel, is featured by lighter, longer service life, non-pollution and more 30% electric quantity storage than nickel-cadmiun battery. The disadvantages of NI-MHbattery is its higher price than nickel-cadmiun battery and lower-qualify than lithium-ion battery.
Lithium iron phosphate pole material, mainly in lithium ion battery, is used in olivine structural lithium battery for poles. Compared with pole materials for traditional secondary cell, LiMn2O4 with spinel structure and LiCoO2 with stratified structure, LiFePO4 is endowed with reversibility of immigrating-taking off from lithium. This character makes LiMPO4’s materials source more abroad, cheaper and non-pollution. When charging, huge multiplying power can be used, and fully charged within one hour at the soonest.
All lithium battery, including Li-ion、IMR、LiFePO4, we suggest, should be charged within 1C. Battery with small capacity should be charged in low current. If small capacity battery charged with electric current over 1C, its lifetime will be impaired enormously, even explode. C means numerical value of battery quantity, eg. Lithium battery with 2600mAh, 1C=2.6A; Lithium battery with 3400mAh, 1C=3.4A Special notes: when charged with Miboxer C4’s charger, electric current ,by default, is 800mA. Please set low electric current (350mA) for charging.
When fully charged, NiMH’s voltage is at its peak, but declines at the process of over-charging. The electric reduction can be used to decide weather battery charges fully or not. Why does electricity reduce? The reason is that electromotive force of battery will reduce with rising of temperature. Where does heat come from? On the one side, battery itself has internal resistance,(Q= (I^2)*R*t). This part of heat is in little quantity. On the other side, in NiMH’s designation, capacity of hydrogen storage material of negative pole is larger than that of positive pole on purpose. In that case, materials in positive pole will complete charge in advance, and produce oxygen by decomposing water. These oxygen, spread by electrolyte, react with hydrogen on surface of hydrogen storage material in negative pole.(hydrogen storage material is good catalyst for recombination of H2 O2.) At last, it releases lots of heat, and back to electrolyte after producing water. This guarantees battery cannot excess pressure easily. Two parts of heats are conversed from electric current, and the temperature rises highly. Electromotive force of battery can reduce from ten more mv to dozens of mv.
When in little electric quantity, battery must charged in low current. Trickle charging, in general, is to protect battery from charging in heavy current. To some voltage, battery has been activated completely, electric current increase gradually. For saving time and efficiency, it starts to charge in constant current. With gradual increase of voltage, especially to 4.2v, battery will be close to saturation, and transfer to constant current charging. At that point, electric current reduce step by step, till its saturation. If electric voltage is higher than 4.2v, battery will be damaged.
Because the NI-MH / NI-Cd battery is fully charged by – ΔV, The charging current will increase twice when the batteries close to full, Quickly release a lot of heat, thereby reducing the battery voltage, and the -△V function effective, that’s why the C4 charger can timely determine the battery saturation and stop charging the battery. And will not overcharge the battery.