Are lithium-ion batteries the end of alkaline batteries? – Digital

Widely used, lithium-ion technology is today essential in the batteries of many devices. Still rare in the segment of HR6 (AA) and HR03 (AAA) type accumulators, commonly called – wrongly – “rechargeable batteries”, it nevertheless brings several advantages over the much more widespread NiMh and even batteries alkaline: higher and constant operating voltage, no memory effect, low self-discharge, light weight and better performance in cold weather. On paper, lithium-ion batteries are therefore full of qualities.

Lithium-ion batteries for what uses?

If NiMh accumulators supply a good number of devices without any problem, advantageously replacing disposable batteries, they suffer from certain limitations which still make it preferable today to disposable batteries for certain specific uses. Their voltage of 1.2 V in particular, can be a problem for certain unregulated electronic devices which still specifically require 1.5 V (children’s toys, flashlights, etc.).

Like alkaline batteries, lithium-ion accumulators are able to deliver this higher voltage. Better yet, they provide it throughout their discharge, which makes them much more efficient than batteries which, for their part, suffer from a rapid drop in their voltage.

Conversely, it may also be advantageous to use lithium-ion accumulators in devices which consume little, but for a long time, such as a remote control. The main obstacle to this, however, comes from the still high selling price of rechargeable lithium-ion batteries, which may lead to the use of simple alkaline batteries or, better, primary lithium batteries (non-rechargeable).

Ease of use and fast charging

In terms of practicality of use also, lithium-ion accumulators take the advantage. Most are indeed equipped with a micro-USB port, allowing them to be recharged simply from any smartphone charger, for example. Convenient if you are on the move, especially as battery brands often provide a micro-USB multi-connector cable to charge several batteries at the same time.

Since it tolerates a higher charging current, the lithium-ion battery is also much faster to charge than a NiMh battery, at least up to a certain percentage of its maximum capacity (approximately 80%); beyond which the current of will be reduced so as not to risk an overload.

Each battery incorporates a BMS (Battery Management System) to control the charge. It is also used to stop the discharge from a certain threshold, again so as not to risk damaging the battery.

A capacity / price ratio that is still not very advantageous

In terms of faults, the integration of this specific electronics reduces the space available in the batteries and therefore limits their capacity. Lithium-ion batteries are also 2 to 3 times more expensive than their NiMh counterparts; count around thirty euros for a set of 4 batteries.

In our laboratory, the specific operation of lithium-ion batteries requires us to adapt our test protocol and our way of evaluating them. Their lower capacity is not necessarily a defect depending on the use that will be made of them, especially as their simpler and faster recharging makes it possible to juggle between several batches of batteries more easily.

The real end of disposable alkaline batteries?

During our lithium-ion battery tests, which you will soon be able to discover in our comparison of “rechargeable batteries”, we wanted to check if they are really comparable to alkaline batteries and if they provide just as good voltage and as much energy. We therefore compared Duracell Plus alkaline batteries to Li-ion batteries from Paleblue and Blackube by subjecting them to a discharge circuit. Verdict for alkaline batteries: respectively 1 h 31 min and 1 h 22 min of discharge before falling below the 1 V bar. In comparison, the Li-ion Paleblue and Blackube batteries in AA format (announced capacity of 1500 mAh) hold for their part 1 h 15 min and 1 h 29 min. The duration is therefore comparable, but the total energy supplied is to the advantage of lithium-ion batteries, since their voltage does not drop during discharge.

With a purchase price of € 34.99 for 4, or € 8.75 per unit, Paleblue lithium-ion batteries are certainly much more expensive than the Duracell Plus, which can be found at € 1.5 l. unit approximately (12 € for 8). At this price, however, it will only take 3 recharges to cushion the lithium-ion batteries. Note that NiMh batteries are still much more advantageous if the charging voltage is not an important criterion for the use you plan to make of them.