Lithium 32650 Battery 101: All About 32650 Batteries
Lithium 32650 batteries are one of the largest standard size cylindrical rechargeable lithium batteries based on several similar lithium battery chemistries with each one offering its own pros and cons.
Lithium 32650 batteries are commonly used in high-power flashlights and other similar devices, for making battery packs for electric scooters, electric bikes, and other electric vehicles, and for many other applications where high capacity lithium batteries are required.
Published: October 21, 2021.
32650 Battery Features and Specifications
32650 battery is a cylindrical battery featuring physical dimensions of (D x H) 32 x 67.7 mm (1.26 x 2.67 inches) with a nominal voltage of 3.2-3.7V and a nominal capacity of 5000-8500 mAh.
The most common lithium battery chemistries used for 32650 batteries are Lithium Manganese Oxide, Lithium Manganese Nickel, Lithium Iron Phosphate, and Lithium Cobalt Oxide, although other similar chemistries are either being developed or are already being offered on the market.
Each of these chemistries has its own pros and cons:
- IMR 32650 batteries feature LiMn204 (Lithium Manganese Oxide) chemistry. Their nominal voltage is 3.6 - 3.7 V per cell, with a maximum recommended charging voltage of 4.2 V. IMR batteries commonly have a smaller capacity but are capable of delivering larger currents.
- INR 32650 batteries feature LiNiMnCoO2 (Lithium Manganese Nickel) chemistry. These batteries are very similar to IMR batteries since they can provide plenty of currents, with slightly lower capacity.
For example, IMR32650 and INR32650 batteries that feature a capacity of "only" 6Ah (6000 mAh), which are able to provide 20-30C currents are actually able to provide currents of 120-180 Amps, with some models being able to deliver even more. And that is a lot of power from a battery that on average weighs 135-170 grams (~4.5-6 ounces).
- IFR 32650 batteries feature LiFePO4 (Lithium Iron Phosphate) chemistry. Their nominal voltage is 3.2 - 3.3 V per cell, with the maximum recommended charging voltage of 3.5 - 3.6 V.
- ICR 32650 batteries feature LiCoO2 (Lithium Cobalt Oxide) chemistry. Their nominal voltage is 3.6 - 3.7 V per cell, with the maximum recommended charging voltage of 4.2 V. They commonly have higher capacities, but maximum allowed currents are often limited to just a few C.
Even when limited down to just 2-3C, IFR32650 and ICR32650 batteries are usually able to provide 12-25 Amps, which is more than enough for flashlights and similar devices, toys, and tools.
But, regardless of the battery chemistry, it is very important to read the battery's documentation provided by the manufacturer since the different batteries based on the very same chemistry can have different discharge characteristics.
Protected 32650 Batteries
Most 32650 batteries offered on the market are "protected" 32650 batteries - they feature a built-in Battery Management System (BMS) that protects (hence the name "protected 32650 battery") the battery from events that may harm the battery like high/low voltage, short circuit, high current, high/low temperature and similar.
Even the IFR32650 (Lithium Iron Phosphate, LiFePo4) batteries, which are considered the safest of all lithium batteries should have protective BMS since lithium batteries are sensitive to overcharging, over-discharging, high/low temperature, and similar events.
When 32650 or similar batteries are used for making battery pack, they should all be connected to the battery's central BMS that protect the individual cells, but also that periodically balances the cells, prolonging their operating life.
Depending on the storage and operating temperature, discharge and charge conditions, quality of the battery cells, and similar, individual 32650 batteries and battery packs made using 32650 batteries may support a few hundred to a few thousand charging/discharging cycles down to 80-100% DoD (Depth of Discharge).
Since BMS modules take some volume of the battery, protected 32650 batteries may have somewhat lower capacity, or the manufacturers may prolong the battery from 67.7mm up to 70.0mm.
But 32x70mm battery is no longer a 32650 battery, but a 32700 battery, which in many devices may fit perfectly in the 32650 battery compartment. We emphasize this "may fit" ...
If You plan on switching from 32650 battery to 32700 battery, please check the device/tool/toy documentation if it can accept both 32650 and 32700 batteries or just 32650 battery.
32650 Battery Terminals
32650 batteries are used in all types of devices and applications, thus they are offered with flat-top terminals, button-top terminals, they may have terminals with soldering tabs or even with screws.
Regardless of the terminal type, battery contacts must be firm in order to prevent energy losses due to the additional contact resistance, especially when the battery is being discharged with strong currents.
32650 Battery Flashlights - 18650 vs 26650 vs 32650 Battery
Flashlights based on the 32650 batteries are very similar in length to the flashlights based on the 26650 and 18650 batteries, except that they appear more robust and stocky due to the battery diameter.
But, 32650 batteries offer larger volume and thus larger effective capacity when compared with 26650 and 18650 batteries, ensuring longer flashlight's runtime and stronger light beam.
On the other hand, flashlights based on the 32650 batteries tend to be somewhat heavier than 26650 flashlights and especially than 18650 flashlights.
If You are looking for strong, high-capacity LED rechargeable flashlights, all three battery sizes offer excellent models, so choose according to your own needs and requirements.
Long Story Short: Lithium 32650 rechargeable batteries are a high-capacity and reliable energy source that also cycles well.
When choosing the right 32650 battery, check its capacity, voltage, chemistry, and the terminal type and go for the model from reputable brands.
Note: Like all other lithium batteries, 32650 batteries must be recharged using battery chargers dedicated to charging of such batteries.