Comparison Panasonic Eneloop BQ-CC87 + 4xAA 2000 mAh vs Panasonic Flagship Charger BQ-CC65E

The battery technology that the charger is compatible with. Modern batteries can be manufactured using different technologies (Ni-Cd, Ni-Mh, Li-Ion, LiFePO4, IMR), each has its own characteristics and requirements for the charging procedure; therefore, for a specific battery, it is worth choosing a charger for which compatibility with the corresponding technology is directly stated.

— Ni-Cd. Nickel-cadmium batteries are one of the oldest types of rechargeable cells. Nevertheless, they are still used quite widely today — in particular, Ni-Cd batteries are considered optimal for devices with relatively high current consumption and increased reliability requirements. Such batteries are resistant to low temperatures, easy to store, reliable and safe. One of the main disadvantages of this technology is the “memory effect”: the battery capacity decreases after it is put on charge without being completely discharged. However, this point is more related to the features of charge controllers, and not to the technology itself, and the use of advanced controllers can be reduced to almost zero. But from the unambiguous shortcomings, one can mention the “non-environmental friendliness” of both the batteries themselves and their production.

— Ni-Mh. Nickel metal hydride cells were created in an...attempt to improve on the nickel cadmium cells described above. The creators managed to achieve a higher capacity (with the same battery size), in addition, Ni-Mh cells are environmentally friendly and completely devoid of the memory effect even when using the simplest charge controllers. The disadvantages of this option, compared with Ni-Cd, are relatively low resistance to frost, shorter service life and more difficult storage conditions, especially for long periods.

— Ni-Zn. A technology that is the same age as Ni-Cd and also survived to this day. Nickel-zinc cells are notable for their higher capacity than other "nickel" batteries, as well as higher voltage, which, moreover, remains at the operating level almost until the charge is exhausted. The latter is especially convenient for digital cameras — this technique is quite demanding on voltage. However, for a number of reasons, Ni-Zn technology has not gained much popularity. The main of these reasons is the short service life (about 300 – 400 charge-discharge cycles).

— Li-Ion. A type of battery, widely known primarily for portable electronics like smartphones or players, but has recently been successfully used in other types of equipment. Lithium-ion batteries combine good capacity with compactness, charge fairly quickly and are devoid of the "memory effect". Their main disadvantages are high cost, poor suitability for work at low temperatures and some probability of fire during overloads and failures.

— LiFePO4. A variety of the Li-Ion batteries described above, the so-called "lithium iron phosphate". The advantages of such cells over classical lithium-ion ones are, first of all, a stable discharge voltage (until the energy is exhausted), high peak power, long service life, resistance to low temperatures, stability and safety. In addition, due to the use of iron instead of cobalt, such batteries are also safer to manufacture and easier to dispose of. At the same time, they are noticeably inferior to lithium-ion in terms of capacity.

— IMR. This abbreviation is used for lithium-ion-manganese-oxide batteries, another variation on lithium-ion technology; the designation LiMn also occurs. Improvements introduced in this version include thermal stability (reduced risk of ignition in case of failure), durability and low self-discharge rates (the latter simplifies long-term storage). At the same time, many IMR batteries are claimed to be compatible with standard "chargers" for lithium-ion cells, but it is best to use specialized devices (in particular, due to low internal resistance and increased risk of overdischarging).

The method of indicating work, in other words, the type of notifications provided for in the design of the charger.

— LED. LED indicators can give messages by turning on and off, blinking at a certain frequency, and changing colours. They are cheaper than displays (see below) and are more visible from a distance, but less informative and more limited in their capabilities.

— Display. Chargers tend to use simple LCD displays. However, even such screens are much more informative and visual than LED indicators. A wide variety of information can be displayed on the display, and in a form that is convenient for perception: the user does not need to remember what this or that light means, he immediately sees a specific message, for example, “Charging is over”. However and this convenience is much more expensive.

The smallest current that the device can provide in charge mode. If this parameter is specified in the specifications, this means that this model has the ability to adjust the charge current (otherwise, only the maximum current is indicated).

Charging current is one of the most important parameters for any charger: see “Maximum charge current. And the general range of current adjustment depends on this indicator: the lower the minimum value (with the same maximum) — the more extensive the possibilities for setting up the "charger" for the specific specifics of work.

The highest current that the device can provide when charging the battery (or the nominal value of the charging current, if it is not adjustable).

Charging current is one of the most important parameters for any charger: it determines the speed of the process and compatibility with certain batteries. In general, the higher the current, the faster the process, the less time it takes to charge. At the same time, some batteries may have recommendations for the optimal current strength and restrictions on its maximum values. Therefore, mindlessly chasing a powerful charger is not worth it: at first it's ok to clarify how justified such power will be.

Note that in multi-channel devices (see "Independent channels"), the maximum current strength can be achieved when only part of the channels are operating. The indicators provided when all channels are operating simultaneously are indicated separately for such models (see "Charge current (all channels)").

The highest current provided by a multi-channel charger (see "Independent channels") at full load, with all slots (and, accordingly, channels) operating. In fact, a guaranteed maximum current provided by a multi-channel charger, regardless of the number of channels involved.

For the total charge current, see “Maximum charge current. Here we note that the full load is a rather complex mode in which the current strength can decrease. Therefore, this parameter is specified separately.

The number of separate charge current settings (see above) provided in the design of the charger. For example, a device with 4 settings may provide options for 200, 400, 800 and 1000 mAh. In general, the larger this number, the more accurately you can choose the charging current for a particular situation.

Ability to operate the device in drip charge mode.

Drip charging is called charging a battery at low currents — on the order of several tens of milliamps — used to compensate for self-discharge ("volatilization" of accumulated energy over time). This function is relevant mainly for Ni-Cd and Ni-Mh batteries, which have quite significant self-discharge rates: it allows you to constantly keep them fully charged. This is especially useful in cases where the battery may be needed at any time (but it is not known exactly when).

Pre-discharge is useful for batteries that are prone to memory effect - they need to be charged only after the charge is completely depleted. In accordance with the name, a charger with this function is capable, if necessary, of discharging the installed battery “to zero” before starting charging. At the same time, some models are able to automatically detect the presence of residual energy and turn on a preliminary discharge, in others it must be turned on manually.

The capacity recovery function will be useful for batteries with memory effect - this time tech whose capacity has already declined. In this mode, the charger discharges and charges the battery several times in a special way, which eliminates the memory effect and restores the battery, if not to the original, then at least to a capacity close to this value.