You cannot charge non-rechargeable alkaline batteries

Recharge normal batteries?

Alkaline battery chargers; Photo: Wolfgang Melchert

There are accumulators and there are batteries. Batteries have a voltage of 1.2 V.(1) and are rechargeable, batteries have a voltage of 1.5 V.(2) and are not rechargeable, but must be thrown away after use(3). Such is the general opinion. In fact, however, many batteries can be recharged a few times with suitable chargers(4) and thus reduce battery waste. In the following article, this possibility and the problems associated with it are described in more detail and an offer from the environmental center for charging batteries is presented.

In many devices it is preferred to use batteries and not rechargeable batteries, because batteries have a higher voltage and because they discharge less strongly when they are not used for a long time. In return, one accepts that batteries have to be thrown away after use. In fact, however, it is known in specialist circles that certain batteries are basically rechargeable, namely batteries with alkaline manganese technology. This does not apply to batteries with zinc-carbon technology, they are really not rechargeable. Only alkaline batteries that are marked as such by the “Alkaline” label can be recharged. A few years ago there were even batteries optimized for recharging under the name of RAM cells(5)which have since disappeared from the market.

Alkaline batteries can only and exclusively be charged with special chargers designed for this purpose(6). Under no circumstances should chargers be used for batteries that are unsuitable due to the different voltages and charging currents! Alkaline batteries can be charged approx. 1 to 5 times, i.e. significantly less often than rechargeable batteries. It is also only possible to charge batteries that are not yet completely discharged but still have sufficient residual voltage(7). Unfortunately, many alkaline batteries have problems charging(8), which is why it is strongly discouraged that everyone experiment with it themselves. A certain proportion of the batteries will run out after charging and must be disposed of, others fail with an internal short circuit(9). According to the author's experience and information on the Internet, the success rate when charging is only around 50%. The batteries must therefore be safely stored and monitored for some time after charging and can only be used again if they have not leaked and are still at full voltage.

So that not everyone has to experiment and deal with these problems, the environmental center offers to recharge alkaline batteries with a suitable device. We check whether the batteries are suitable at all, charge them, then store them for 1-2 weeks and check them for leaks and the voltage they have received. Batteries that do not survive this we dispose of properly, the remaining usable batteries can be picked up again. The use of these charged batteries is at your own risk, the environmental center is not liable for any damage that may result from a possible leakage of the batteries, which can also happen with new batteries. The recharged batteries should therefore not be used in high-quality devices, but rather in flashlights or watches, for example. Please only charge batteries you have used yourself and do not plunder public battery collection boxes, as their contents are questionable!

Wolfgang Melchert


(1)Batteries in NiMH or NiCd technology; for batteries with several cells connected in series according to z. B. 2x 1.2 V = 2.4 V or 6x 1.2 V = 7.2 V. Lead batteries for vehicles and large devices have different voltages, usually 6 V or 12 V.

(2)For batteries with several cells connected in series according to z. B. 2x 1.5 V = 3 V or 6x 1.5 V = 9 V.

(3)Do not dispose of used batteries in the household waste, but in the battery collection boxes provided for this purpose!

(4)You can find a variety of sources on the subject on the Internet, e. B. at Wikipedia. The article is based on these sources and on the author's own experience.

(5)RAM = Rechargeable Alkaline Manganese, manufactured e.g. B. from Rayovac and Accucell.

(6)Suitable chargers are e.g. B. MaximalPower FC999 and (identical) M.A.N.Z. RC999 (available by mail order), as well as chargers for RAM cells, such as Rayovac PS1 and PS3, Accucell ACL 62 and ACL 64 (only available as remaining stock on auction portals).

(7)To test the batteries, you need measuring devices that test the batteries under load and not just when idling.

(8)Batteries from certain manufacturers appear to be particularly problematic when charging, e.g. For example, the author was unable to charge a single copy successfully in a few 10 attempts with batteries from one manufacturer, whereas all charges were successful with another manufacturer.

(9)This is also the reason why the manufacturers write the warning “not rechargeable!” On the batteries, because no manufacturer wants to be associated with leaked batteries or be liable for any damage caused by them.

This is an article in the Karlsruhe magazine Environment & Traffic 1/15

Status of the article: 2015! The content of the article may no longer be up-to-date, the author can no longer be reached, etc. Please also have a look at ours Subject index.

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