What do the letters on a lithium battery stand for?

Let's talk moment about the meaning of the letters and figures on batteries, for illustration for lithium polymer( LiPo) batteries used in electric RC aircraft, we generally see several standard electrical terms" voltage" or" number of cells";" storehouse capacity"; and" current" or" emigration rate limit." With any LiPo marker, we will see at least these three particulars. They're terms used in all electrical fields, so it's important to know what they mean and to use them rightly, so let's read on! 

1.Voltage 

A battery consists of cells, which are connected in series and/ or in resemblant to form a cell. The voltage of any battery depends on the chemical composition of the accoutrements within the cell. Nickel- cadmium( Ni- Cd) batteries have a reference or nominal voltage of 1.2 volts per cell. Lead acid batteries have a nominal voltage of 2.0 volts per cell. A typical LiPo battery has a nominal voltage of3.7 volts per cell. 

The total cell voltage is a multiple of the cell voltage, so six lead- acid cells make up a 12 volt battery. The three cell series( 3S) LiPo is labelled"11.1 volts" and the 6S cell is labelled"22.2 volts". In a completely charged state, the LiPo cells will have a voltage close to 4.2 volts per cell and a cut- off or minimal permissible voltage of3.0 volts per cell. 

The two 5000mAh cell markers show different C rates. the palpitation cell shows a single 45C rate, while the Turnigy shows a range of 25C to 50C. Although not explicitly stated, I believe the lower is a nonstop standing, while the advanced standing is 30 seconds. Note that no rate is specified on either marker. 
 

The markers for these batteries show energy capacity in watt-hours in addition to storehouse capacity in amp- hours. theE-flite marker specifies the charging voltage, while Electri Fly specifies the charging current. 
 

2. Storehouse capacity 

The storehouse capacity( C) of a battery is described as the quantum of charge it can deliver over a period of time while remaining above the cut- off voltage, and is basically determined by the size of the battery. generally, larger LiPo cells have a lesser capacity, as do larger Ni-Cds. Capacity is measured in amperes-hours( Ah) or milliamperes-hours( mAh) and is defined by the number of hours the battery can deliver a given discharge current. This means that a battery with a capacity of 1Ah is able of delivering one ampere of current for one hour before reaching its cut-off voltage. It can also deliver 500mA for two hours, or two amps for half an hour. Josh Barker of Max Amps verified to me that the assiduity standard for marker capacity is a one hour discharge rate. 

Note up, storehouse capacity it isn't a constant. adding the discharge current will reduce the capacity of the battery and like wise the temperature axes. It's also worth noting that we infrequently use the full capacity of the battery as doing so can damage the battery and dock its life. I calculate the flight time so as to land the batteries near to their storehouse voltage3.8 volts per cell. This leaves about 45 of the capacity unused, but it allows for a safe periphery on failed wharf attempts and the batteries are easy to use. It's also easy for me because formerly I have completed the flight I do not have to charge or discharge to storehouse situations. 

3. Using the" C" 

1) In all batteries, capacity is used to define several other rates, similar as charge and discharge rates, which can make effects a little confusing. Charging a battery inaptly can damage it, so the manufacturer specifies a safe maximum charge rate, in multiples of C. For the LiPos we use, a charge rate of 1C is nearly always safe and easy to charge the battery. Some manufacturers specify advanced charging rates. palpitation Batteries and MaxAmps, for illustration, specify a charge rate of 5C, so I'll use that rate from time to time. For regular charging, I stick to a further moderate 1C rate as I suppose it helps the battery last longer. 

2) The term" C-rate" is used to define the discharge current of the battery. As with rate, this number is specified as a multiple of C,e.g. 20C. occasionally the marker will show a range,e.g. 25- 50 C, and occasionally it'll show a nonstop and palpitated, or 30 alternate rate. The nonstop C rate is the maximum discharge current the battery can deliver for a full discharge, from full charge to cut- off voltage, without damaging the battery. the 30 alternate C rate is the maximum discharge current the battery can deliver for a short palpitation without damaging the battery