Many modern led flashlights are fitted with CR123A lithium batteries. These batteries are disposable, also known as primary batteries. In view of the replacement cost of these batteries, users have been looking for a rechargeable substitute.
Today, many battery manufacturers do offer a solution to this search: the CR123A rechargeable battery. This article is intended to discuss PROs and CONs about these batteries with a word of caution about their use.
The CR123A rechargeable cell is also known as RCR123A which are typically about 1mm longer than is standard CR123A.
RCR123A cells are designed as replacement to the standard CR123A, but keep in mind that sometimes RCR123A can output a higher voltage than standard 3V for CR123A.
Actually, it has been found that there are two classes of RCR123A cells:
- one is giving an output voltage of 3.0 to 3.2 V whereas
- the other class is outputting 3.7 to 4.2 V for a fully charged cell.
Compared with the primary CR123A battery, the CR123A rechargeable battery has a lower capacity. On the positive side, they do not suffer from the well-known memory problem which is a serious drawback on Ni-Cd batteries.
A number of flashlights are designed to work with two RCR123A. Many of them can also be powered with one 18650 rechargeable battery. The latter can store more electricity (has more ampere hours (Ah)) than two RCR123A cells.
- Due to the physical differences, don’t forget to check the physical compatibility of the desired cell with your particular flashlight.
- Consult your flashlight manual to make sure that internal regulator chip can handle the higher voltage delivered by the CR123A rechargeable, especially if you plan to use the higher output type.
- When you use a regulated flashlight at high output mode, it will step down to the next lower mode when the battery reaches a certain voltage. This will happen earlier with the RCR123A.
- RCR123A batteries can be recharged when only partially depleted without adverse effect.
- If your flashlight uses two CR123A cells, I would recommend getting one 18650 instead of two RCR123A’s. They turn out to be cheaper in the long run due to their higher storage capacity.
As these batteries are Li-Ion they may explode when overheated, overcharged or over discharged. Most rechargeable cells are equipped with a minimum safety feature protecting them against over temperature in the form of an auto-resettable fuse (PTC) and an over pressure protection (CID).
An additional safety feature is found in high-end batteries. It is an electronic circuitry which safeguards batteries from over charge, over discharge and over current drain. It is called a Protective Circuit Board (PCB).
This board is placed at the bottom of the battery (negative end). A battery equipped with such a board is slightly bigger and longer than a standard battery.
- One of the most important things when choosing a battery is to check if it is fitted with a Protective Circuit Board (PCB).
- Check if your flashlight can receive the protected cell in terms of size.
- However you should know that the PCB brings a small reduction in the high power performance of your flashlight.
There are RCR123A’s that are made with LiFePO4 (lithium iron phosphate). They offer a longer life cycle than other lithium-ion and higher current or peak-power ratings. However, their energy density is 14% lower. LiFePO4 batteries tend to be a little bit bigger than Li-Ion.
On another hand, they have a slower rate of capacity loss (greater shelf life) than standard lithium-ion batteries.
- Caution is advised when choosing a LiFePO4 cell. Make sure it fits into your flashlight.
- Batteries don’t cost a fortune so Li-Ion may still be preferable because of their higher energy density. On the other hand they have a shorter life cycle. It’s your choice to assess the balance between them.
- LiFePO4 cells are supposed to be intrinsically safer than other Li-Ion cells therefore they can be unregulated.
- Rechargeable CR123A’s are called RCR123A’s. They are an economical alternative to primary (non-rechargeable) CR123 cells.
- One can choose between LiFePO4 and Li-Ion technologies: Li-Ion has more energy density but LiFePO has greater cycle life, has higher current capability.
- For a safe use of Li-Ion batteries it is recommended to choose a model fitted with a Protective Circuit Board (PCB). Avoid cheap brands that do not present the same high characteristics in terms of performance and safety (presence of a PCB but also chemical content). It is wise to rely on well known manufacturers.