9V Lithium Batteries
The most popular 9V lithium battery is a lithium battery simply labeled as a 9-volt battery, also known as E battery, PP3 battery, 6LR61 battery, 6F22 battery, 1604A battery, 1604D battery, MN1604 battery, etc.
9V lithium batteries are offered as non-rechargeable and as rechargeable batteries and are used to power various smaller devices including remote controllers, toys, flashlights, security systems, and similar.
9-volt flat/rectangular battery features physical dimensions of (H x L x W) 48.5 x 26.5 x 17.5 mm with a nominal voltage between 7.4V and 11.1V and capacity between 200mAh and 1200mAh.
Note that the 9-volt flat/rectangular is offered in other chemistries as well, including zinc-carbon, alkaline, NiCd, NiMH, etc.
But, lithium 9-volt flat/rectangular batteries offer the best capacity with rather stable voltage.
9V lithium batteries feature 2-3 lithium cells connected in series in order to achieve 7.4-11.1 volts, depending on the exact battery chemistry.
The following comparison chart lists some of the most popular 9-volt battery chemistries with their most important features and specifications:
|Battery Type||Typical Capacity||Nominal Voltage|
|NiCd||100-120 mAh||7.2, 8.4, 9.6V|
|NiMH||175-300 mAh||7.2, 8.4, 9.6V|
|Lithium Polymer||500-550 mAh||7.4V (11.1V)|
|Lithium-Ion||600-650 mAh||7.4V (11.1V)|
For a long time, the most popular 9V batteries were non-rechargeable zinc-carbon and alkaline 9V batteries consisting of 6 (six) cells internally connected in series in order to provide 9 volts.
As soon as the battery is being used, actual voltage drops below 9 volts, with most devices intended for 9V battery supporting input voltage down to 6-7 volts.
Non-rechargeable 9V lithium batteries are based on the Lithium Manganese Dioxide (Li-MnO2) chemistry and feature 3 (three) 3V cells connected in series in order to provide a nominal voltage of 9V, a cutoff voltage of 6.0 volts, and a nominal capacity of ~1200 mAh.
Also, many Li-MnO2 9V batteries are able to provide rather strong currents, often in excess of 1 Amp.
Rechargeable 9V lithium batteries are based on various lithium battery chemistries, including Lithium Polymer, Lithium-Ion, and Lithium Iron Phosphate (LiFePO4) chemistry.
Lithium Polymer and Lithium-Ion 9V batteries can have two cells connected in series in order to achieve a maximum voltage of 8.4 volts and a nominal voltage of 7.4V or they can have three cells connected in series in order to achieve a maximum voltage of 12.6 volts and a nominal voltage of 11.1V.
Most Lithium Polymer and Lithium-Ion batteries have TWO cells in series - devices intended for 9V non-rechargeable batteries can operate with voltages below 9V (usually down to 6V), however, higher voltages can even damage sensitive devices.
Lithium Iron Phosphate (LiFePO4) batteries have 3 (three) 3.2V cells connected in series in order to provide 9.6V - in most cases, devices intended for non-rechargeable 9V batteries work just fine with 9.6V LiFePO4 batteries.
But, just in case, if You plan on powering a 9V device with a 9.6V battery, check the documentation of the device if it is safe to power it by 9.6V battery.
Long Story Short: Lithium non-rechargeable 9V battery offers the best capacity (1200 mAh) and the most stable output voltage of all 9V battery chemistries and it is directly compatible with older 9V zinc-carbon and alkaline 9V batteries.