Sub-C Rechargeable Battery

Sub-C batteries are commonly used in cordless tools, high-end RC toys, and appliances requiring reliable batteries that are able to provide relatively strong currents and support hundred of charging/discharging cycles.

Sub-C batteries are offered in several chemistries, but also in several sub-models, often labeled as 1/2 Sub-C, 4/5 Sub-C, and 5/4 Sub-C batteries.

Published: June 23, 2022.

Sub-C Battery Features and Specifications

Sub-C batteries are cylindrical batteries featuring physical dimensions of (D x H) 22.2 x 42.9 mm (0.874 x 1.689 inches), which is often abbreviated as 23 x 43 mm (~0.9 x 1.7 inches).

These batteries are offered as rechargeable Nickel Cadmium (NiCd) and Nickel Metal Hydride (NiMH) batteries. Although these two chemistries share some features, they also differ in many more - when replacing old Sub-C batteries always replace them with the batteries featuring the same chemistry.

Sub-C batteries are also labeled as Sub C battery, Sub C-Cell battery, SC battery, 332 battery, KR22C429 battery (NiCd), HR22C429 battery (NiMH), etc. But, practically all batteries feature "Sub C" or "Sub-C" or "SC" as part of their labels.

Sub-C NiCd Battery

Rechargeable Sub-C Nickel Cadmium (NiCd) batteries are an older type of rechargeable Sub-C batteries.

These batteries feature a nominal voltage of 1.2V, and nominal capacity in the 1200-2400 mAh range, although the actual capacity depends on the battery use, temperature, age, and similar.

Pros of NiCd Sub-C batteries are their price and the ability to provide strong currents - most models are able to provide 10C currents without any adverse issues.

On the other hand, NiCd Sub-C batteries contain toxic Cadmium and MUST be recycled properly. Also, they support a relatively low number of charging/discharging cycles (200-300 cycles, although some manufacturers claim 400-500 cycles) and have a very strong memory effect - they should often be fully discharged before being recharged again.

These are the reasons why NiCd Sub-C batteries are being replaced with NiMH Sub-C batteries in most applications.

Sub-C NiMH Battery

Rechargeable Sub-C Nickel Metal Hydride (NiMH) batteries also feature a nominal voltage of 1.2V, and a nominal capacity of 1800-5000 mAh, with a maximum allowed discharge current rarely above 10C.

Sub-C NiMH batteries don't suffer from memory effect, they don't contain dangerous Cadmium, they support a larger number of charging/discharging cycles (often 500-600 cycles), etc.

But, they should also be recycled properly.

Although both NiCd and NiMH Sub-C batteries feature the same nominal voltage of 1.2V, they should be recharged only using battery chargers intended for NiCd or for NIMH batteries, or they can overheat and cause other issues.

Sub-C Lithium Ion Battery

Rechargeable Sub-C Lithium Ion batteries are not (yet) available on the market or if they are, they are very rare.

These batteries potentially have larger voltage (3.2-3.7V) and are able to store more energy. However, lithium-ion batteries are not compatible with battery chargers intended for NiCd and NiMH batteries (unless the charger has a charging mode for lithium batteries as well).

Also, lithium-ion cells must be protected from unwanted events like over and under charge, too strong charging/discharging currents, high/low temperature, etc., and are offered in dimensions other than Sub-C battery dimensions (~23x43 mm).

Most brands that offer tools, appliances, toys, and electric vehicles (electric scooters, for example) are using larger lithium-ion cells to create much larger battery packs.

Sub-C Batteries With or Without Tabs

Sub-C batteries are offered with both soldering tabs and without soldering tabs.

For people looking for replacement batteries for various tools, Sub-C batteries with soldering tabs are a much better choice since soldering tabs allow the users to create replacement battery packs of the required size and shape without overheating the batteries.

On the other hand, some tools, toys, and appliances feature battery compartments requiring Sub-C batteries without tabs - when replacing the batteries from such battery packs, always replace all the batteries with new batteries which are the same model from the same manufacturer, preferably from the same batch.

Better safe than sorry...

Sub-C Batteries vs C-Cell Batteries

Sub-C batteries are smaller than C-cell batteries (~23x43 mm vs ~26x50 mm), hence the "Sub" as part of their label.

While Sub-C batteries are rechargeable NiCd and NiMH batteries, C-cell batteries are offered as primary (Zinc-Carbon, Alkaline, Lithium Manganese Dioxide (rare), and Lithium Thionyl Chloride (Li-SOCl₂) batteries) and as secondary (NiCd, NiMH, lithium-ion) batteries.

Thanks to their larger size, C-Cell batteries feature a larger capacity (among other differences).

But, battery packs made from C-Cell batteries are often too large for lightweight cordless tools, which require Sub-C or similar batteries.

1/2 Sub-C, 4/5 Sub-C, and 5/4 Sub-C Batteries

1/2 Sub-C, 4/5 Sub-C, and 5/4 Sub-C batteries are very similar to Sub-C batteries in terms of chemistry (NiCd or NiMH), diameter (~23 mm), and use (for cordless tools, appliances, toys, and similar), but they differ in height:

• 1/2 Sub-C Height: ~21.5 mm,
• 4/5 Sub-C Height: ~34.5 mm,
• 1/1 Sub-C Height: ~43 mm,
• 5/4 Sub-C Height: ~54 mm.

Because of different heights, 1/2 Sub-C, 4/5 Sub-C, and 5/4 Sub-C batteries feature different capacities and are used to create battery packs of different heights, ranging from ~22 mm to 55 mm.

All these batteries are offered in versions with or without soldering tabs - when replacing the old batteries, be sure to check the actual battery size, chemistry, number of batteries, and shape of the battery pack, and only then order new batteries and replace ALL batteries from the old battery pack.