9-volt, E battery, PP3, 6LR61, 6F22, 1604A, 1604D, MN1604 Battery Equivalents and Replacements
9-volt, E or PP3 battery is very popular 9V rectangular battery often used in portable radios, cameras, walkies-talkies, smoke alarms, alarm clocks and other applications that require slightly larger voltage from a single battery.
9V batteries can be both non-rechargeable or rechargeable batteries, featuring different chemistries.
Physical dimensions of 9V E or PP3 battery is 48.5 mm height, 26.5 mm length and 17.5 mm width. Battery terminals are positioned on the same battery end: '+' is male clasp, and '-' is female clasp.
Its most common names include 9V battery, 9-volt battery, E battery, PP3 battery, MN1604 battery and similar.
Labels according to IEC and ANSI standards depend on the chemistry involved.
According to IEC:
- 6LR61 (alkaline),
- 6F22 (carbon-zinc),
- 6KR61 (nickel-cadmium),
- 6HR61 (nickel-metal hydride).
According to ANSI standard:
- 1604A (alkaline),
- 1604D (carbon-zinc),
- 1604LC (lithium),
- 7.2H5 (nickel-metal hydride),
- 11604 (nickel-cadmium),
- 1604M (mercury-oxide).
Note that mercury batteries are obsolete and no longer in use.
Nominal capacity of 9V battery depends on the chemistry:
- 550 mAh (alkaline),
- 400 mAh (carbon-zinc),
- 1200 mAh (non-rechargeable lithium),
- 200-250 mAh (nickel-metal hydride),
- 100-130 mAh (nickel-cadmium),
- 500-800 mAh (rechargeable lithium),
- 580 mAh (mercury-oxide).
Nominal voltage of these 9V batteries depends on the chemistry and internal design.
Alkaline 9V batteries often contain six LR61 cells which are very similar with AAAA cells (42.5 x 8.3 mm) - hence IEC labels. However, there are other designs as well, for example, with rectangular cells.
Alkaline 9V batteries have nominal voltage of 9.0 V and cut-off voltage of 6.0 volts.
Lithium non-rechargeable 9V batteries contain three 3V cells providing 9.0 nominal voltage with cut-off voltage of 6.0 volts, just like alkaline batteries.
However, NiCd and NiMH 9V batteries can have 6, 7 or even 8 cells, providing 7.2, 8.4 or 9.6 volts. Modern NiMH batteries feature very low-self discharge rate (sometimes even less than 10% per year), allowing their use in stand-by applications.
Rechargeable lithium 9V batteries have two or three 3.6 volts cells and generally have nominal voltage of 7.2 or 10.8 volts. We say generally since some manufacturers make 9V batteries using lithium ion (7.2 or 10.8V internally) or lithium polymer (7.4 or 11.1V internally) with electronic protection circuitry which monitors battery status, and provide the output under- or over-voltage protection.
Note: when charging lithium 9V rechargeable batteries, it is highly recommended to use battery chargers recommended by the battery manufacturer. Some manufacturers make lithium battery chargers that should NOT be used for charging lithium batteries of other manufacturers due to the protective electronics found in their battery. If you need good and safe rechargeable lithium battery and charger, perhaps the best option is to buy them as the combo/bundle.
For Short: 9V batteries, also labeled as 9-volt, E battery, PP3, 6LR61, 6F22, 1604A, 1604D, MN1604 etc. are common batteries often found in various devices at home. They can be found at local or on-line stores and if required, easily ordered.
If you are unsure which one to take, go for alkaline or lithium non-rechargeable models and don't worry about charging them.
If you need rechargeable 9V batteries, go for the batteries/battery charger bundle/combo of reputable brands.