Battery Types and Chemistries in Home Tools and Appliances
Modern devices more and more rely on batteries of various types, sizes, shapes, and chemistries, regardless if it is a small handheld cordless vacuum cleaner, larger convertible stick unit, ordinary remote control, robot vacuum cleaner, or any other cordless tool or appliance.
Knowing what type of battery fits your unit can be very important when looking for a replacement battery, since manufacturers after discontinuing the cordless tool, often stop manufacturing its spare parts, batteries included.
Published: February 9, 2021.
Primary vs. Secondary Batteries
There are two main battery categories: primary and secondary batteries.
Primary batteries are non-rechargeable batteries and are often used in remote controls, on the motherboards of robotic vacuums and other similar devices, etc.
When discharged, primary batteries are simply replaced with new ones and old batteries are recycled!
Secondary batteries are rechargeable batteries and are commonly used in home appliances, tools, electric scooters, vehicles, etc.
After being discharged, secondary batteries can be recharged and reused again. A number of charging cycles often depends on many things, including the battery chemistry, charging and discharging currents and temperature, battery age, etc.
Most Common Small Battery Chemistry Types
Small batteries use different chemistries in order to achieve desired drain voltage and current, capacity, weight, price, etc.
Most common chemistries include:
Lead-Acid Batteries are types of rechargeable batteries not commonly used in home appliances and tools, but they are often used in cars as starting and dual-purpose batteries, in golf carts, RV vehicles, in marine applications, off-the-grid applications, as UPS backup batteries, in security systems, etc.
Also, lead-acid batteries are often used in large, commercial ride-on floor cleaners, washers, and polishers, since their large weight is not of an issue in such units.
The nominal voltage of a single lead-acid cell is 2.0 volts.
Lead-acid batteries are cheap batteries and can be recycled almost 100%.
AGM (Absorbed Glass Mat) lead-acid batteries use an electrolyte that is held in the glass mats made out of very thin glass fibers. AGM batteries are non-spillable batteries that can be operated in any position and are slowly phasing out flooded-cell lead-acid batteries from automotive and marine applications.
Nickel Cadmium (NiCd) batteries are types of older rechargeable batteries that were rather common before newer battery types started to replace them.
NiCd batteries are lighter than lead-acid batteries, they can be discharged using strong currents, and are rather cheap.
The nominal voltage of a single NiCd cell is 1.2 volts.
However, since they contain cadmium, NiCd batteries are not environment-friendly batteries and they simply MUST be recycled properly.
Also, NiCd batteries suffer from a strong memory effect, relatively high self-discharge rate and the number of their charging/discharging cycles is rather limited, especially when being discharged with strong currents.
Nickel Metal Hydride (NiMH) batteries are rechargeable battery types that were rather common even in high-tech devices just a few years ago.
Modern NiMH batteries are lighter than NiCd batteries in terms of capacity/energy, have very low memory effect (no memory effect if you ask their manufacturers, but ...), very low self-discharge rate, generally good discharging features, they are environment-friendly batteries that should also be properly recycled, they are rather cheap, etc.
The nominal voltage of a single NiMH cell is 1.2 volts.
Entry-level handheld vacuums still use NiMH batteries, since they are cheaper than rechargeable lithium-ion batteries, and they are very reliable in use.
Note: some NiMH batteries are designed for larger capacity and some are designed for high discharge currents. So, when looking for a replacement, be sure to know the maximum required current of your device.
Rechargeable lithium-ion batteries are commonly used in modern vacuum cleaners, cordless tools, and other similar applications where a strong, lightweight, fade-free power battery is required, despite a slightly higher battery price.
Rechargeable lithium-ion batteries nominal voltage is 3.6-3.7 volts per single battery cell - nominal voltage varies since there are several lithium-ion chemistries that are very similar, but have slight performance differences:
- Lithium Manganese Oxide (LiMN2O4, also known as IMR batteries) feature nominal voltage in 3.6-3.7 volts range, with the maximum safe voltage of 4.2 volts. Although these batteries have lower capacity when compared with other lithium-ion batteries, they are able to produce large currents.
- Lithium Manganese Nickel or Lithium Manganese Cobalt Nickel batteries (LiNiMnCoO2, also known as INR batteries) are very similar to Lithium Manganese Oxide batteries, providing slightly lower capacity, but large discharge currents.
- Lithium Iron Phosphate batteries (LiFePO4, also know as IFR batteries) feature slightly lower nominal voltage (3.2 - 3.3 volts per cell). But, they are also very safe to use and tolerate a large number of charging/discharging cycles.
- Lithium Cobalt Oxide batteries (LiCoO2, also known as ICR batteries) feature a nominal voltage of 3.6-3.7 volts, with a maximum charging voltage of 4.2 volts. These batteries have a very large capacity, but their safe discharging currents are often limited to just a few C. For example, a 5 Ah battery rarely can provide more than 15-20 Amps of currents, safely.
When looking for the lithium-ion replacement battery, be sure to aim for the battery with the same chemistry (if known), and the same or larger capacity and maximum allowed charging/discharging current.
Note: never, but really never charge these batteries with the chargers designed for some other battery type. They can easily burst into flames (or even explode) if charged with too strong currents or if they are overcharged.
Non-rechargeable lithium cylindrical/button/coin batteries feature 3 volts nominal voltage and depending on the size and shape, can be found in remote controls, EDC (Every Day Carry) flashlights, and similar devices, on the motherboards, etc.
Non-rechargeable lithium batteries feature lithium negative electrode, while positive electrode is either manganese-dioxide or carbon-monofluoride.
Manganese-dioxide lithium batteries are more common, have an operating temperature range between -4°F (-20°C) and 158°F (70°C). The nominal voltage is 3.0 V, with a cutoff voltage of 2.0 V.
Carbon-monofluoride lithium batteries feature an operating temperature range between -22°F (-30°C) and 185°F (85°C). The nominal voltage is 2.8 V, and the cutoff voltage is 2.25 V.
Non-rechargeable lithium cylindrical/button/coin batteries come in a large number of shapes and dimensions. The most common types are CR123A and CR2032, but there are many others present as well.
Alkaline non-rechargeable batteries appear in various sizes and shapes. Their nominal voltage is 1.5 volts, but the voltage relatively quickly drops over time.
Cut-off is around 1.0 volts, since it depends on the cut-off voltage of the powered device, too.
Alkaline batteries are cheap, reliable, have a good shelf life, and are often used in remote controls, flashlights, toys, and all sorts of other consumer electronics.
Silver-oxide non-rechargeable batteries often come in the form of button/coin cell batteries, used in small remote controls, keychain flashlights, watches, and similar.
These batteries have a nominal voltage of 1.55 volts, with a cut-off voltage of 1.2 volts. During operation, voltage is very stable, with a rather sharp drop at the end of their operational lifetime.
Since silver-oxide batteries have better electrical features than alkaline batteries, some brands offer them in the form of cylindrical batteries like AA, AAA, and similar, although they cost more. Such batteries are often used in high-power, high-drain devices, like cameras and similar.
Zinc-air batteries are a type of non-rechargeable batteries used in hearing aid devices. Their nominal voltage is 1.4 volts and cut-off voltage 1.2 volts.
However, their operating time also depends on the condition of their electrolyte - when it gets dry, the battery is dead, regardless if the battery was discharged fully or not.
That is the reason why zinc-air batteries come with the seal in the form of a tab, which is removed prior to the use.
When the tab is removed, used or not, zinc-air batteries can operate for few weeks, not more.
One of the strong points of zinc-air batteries is that their capacity is on average 3-4 times larger than the capacity of equivalent silver-oxide batteries and 5-6 times larger than the capacity of equivalent alkaline batteries.
Most Common Small Battery Sizes
Small batteries can be grouped in many ways according to their size and shape, but most commonly, they are:
Cylindrical Batteries - very common battery type, with the most popular being A23 batteries (10.3 x 28.5 mm), AAA batteries (10.5 x 44.5 mm), AA batteries (14.5 x 50.5 mm), C batteries (26.2 x 50.0 mm), etc.
The most common chemistries are alkaline (non-rechargeable) and NiMH (rechargeable), although other chemistries are available as well.
Cylindrical Lithium Batteries are very popular batteries in high-power, high-drain devices, in security systems, EDC flashlights, and other similar EDC units, etc.
Most common rechargeable cylindrical lithium batteries are 18650, 26650, 32650, 17340 ('rechargeable CR123A'), 15270 ('rechargeable CR2 battery') etc.
Lithium rechargeable cells of various dimensions are often found at battery packs of most mid-and high-range cordless vacuum cleaners and cordless tools.
The most popular non-rechargeable lithium cylindrical batteries are CR123A and CR2 batteries, often found in flashlights, cameras, toys, security systems, and similar applications where a reliable and strong power source is required. Also, non-rechargeable lithium cylindrical batteries often have a very long shelf life - up to, or even more than 10 years.
Button/Coin Cell Batteries are alkaline, silver-oxide, and zinc-air non-rechargeable batteries, with the most common being (labels depends on the manufacturer, chemistry, standard ...):
- 11.6 x 5.4 mm, also known as SR44W, SR44, SR44SW, 157, 357, 303, SG13, S76, SR1154, LR44, 76A, AG13, LR1154, A76, 675, Blue Tab, ZA675, PR44, 7003ZD etc,
- 9.5 x 2.6 mm, also known as SR927W, SR927SW, SR927PW, SR927, SR926, SR57, 395, 399, SG7, LR57, LR927, LR926, AG7, etc.
- 6.8 x 2.6 mm, also known as SR626, SR626SW, SR66, 177, 376, 377, SG4, LR626, LR66, AG4 etc.
Lithium Non-Rechargeable 3V Button/Coin Cell Batteries are used in low drain devices and are known as the batteries that can hold a charge for many years. Thus, these batteries are often used in computers, laptops, tablets, and other similar devices as motherboard batteries for supplying power to onboard CMOS chips.
Also, these batteries are common in smaller keychain LED lights, remote keys, and similar.
The most common models are CR2032 and CR2025, although many others are available on the market, too.
Small Rectangular Batteries are used in various home appliances and are often available in both rechargeable and non-rechargeable versions.
Most common small rectangular batteries are 9 volts battery (48.5 x 26.5 x 17.5 mm, 9-volt, E battery, PP3, 6LR61, 6F22, 1604A, 1604D, MN1604), 3/3.6 volts CR-V3 battery (52.2 x 28.05 x 14.15 mm, 5047LC, 5047LF, CRV3, RCR-V3) etc.
Power Tool Batteries as Cordless Vacuum Batteries
Many brands that manufacture power tools also manufacture vacuum cleaners suitable as workshop or construction site vacuums. In order to power these vacuums that are often designed as cordless units, they use their in-house batteries already manufactured for their cordless tools.
Such batteries are designed to be used and abused (up to the point, of course) and can reliably provide plenty of power even in the hardest conditions.
So, owners of such power tools and batteries can purchase cordless vacuums as 'bare tools' (very cheap) and use the batteries that they already have.
Such standardization can save plenty of money in the long run.
Cordless Vacuums With The Custom Battery Packs
Most vacuum cleaner manufacturers use custom battery packs for powering their cordless units.
Such battery packs are optimized for individual vacuum cleaners in terms of capacity, voltage, drain current, charging current, and similar.
When such battery pack fails (usually after the warranty has expired), then:
- if the battery can be replaced by the user, the best solution is to order a new battery pack from the manufacturer, if such battery packs are still manufactured.
- if the battery cannot be replaced by the user, the best solution is to visit a certified service center and let them check the unit.
Note: the use of non-OEM batteries is not recommended, although sometimes it is the only possible solution. Or get a new unit, which is not always the most cost-effective thing to do :)
Long Story Short: knowing battery types and chemistries can come rather handy in the modern world, powered and run by electronic devices and gadgets of all sorts.
Although batteries are common household items, handle them with care, keep them away from kids and heat, and in the end, recycle them properly.