Talk:Recharging alkaline batteries

Safety
I changed the section "Explosions" to "safety", because eye injury is a major concern when experimenting with a battery that can potentially spray 10-40% concentrated potassium hydroxide solution. We cannot control what other people will do with this information, but at at the very least we should warn them about the need to take safety precautions. (75.153.112.1 23:16, 9 September 2007 (UTC))

Explanation of failures
Perhaps the article could be expanded, to explain why recharging alkaline batteries is not very successful. Two modes of failure come to mind. One is the formation of dendrites in the zinc electrode that short the battery out. The other is the formation of hydrogen and/or oxygen, which cause the battery to vent.

Duplicated articles
Rechargeable_alkaline_battery also has most of the same information covered. This other article also cites sources. If I knew how to forward pages I would simply redirect this article to the other. —Preceding unsigned comment added by 74.37.90.33 (talk) 17:52, 8 June 2009 (UTC)

Seriously mis-leading
This is a seriously mis-leading article. Recharging alkaline batteries is not merely dangerous and a general waste of time. Eventually you will leak battery liquid onto the contacts of your equipment and do significant damage. If you want to stop wasting money on disposable batteries, get NiMH rechargeables -- they actually work! -69.87.203.130 (talk) 00:57, 18 June 2008 (UTC)

The article now tells that —Preceding unsigned comment added by 94.209.25.26 (talk) 18:34, 7 May 2009 (UTC)

Removed the following: It IS POSSIBLE to recharge your REGULAR ALKALINE batteries.

Doesn't read like an article - rather like and argument, and could lead people to do something foolish. This whole article is really questionable still - there are no statistics, there is no performance data, and the dangers are not nearly well enough specified.

The article reads like a mad scientists blog... 99.190.81.215 (talk) 21:19, 20 April 2010 (UTC)

Disputed claims RE: safety
Some people [|# claim it is safe to recharge primary cells using a technique called [[periodic current reversal]] (AC with a DC offset component). And that manufacturers claims about the "dangers" of attempting to do so are false/exaggerated and based on self-interest. A 1986 series of articles in Practical Electronics magazine (UK) called "Better use of dry batteries" examines this concept in some detail and claims that in Japan the recharging of dry cells is (or was ?) officially encouraged (for environmental/conservation reasons) and that it is (/was ?) illegal there for battery manufacturers to claim that their products are not rechargeable. 86.112.51.161 (talk) 20:00, 8 October 2010 (UTC)

This is for damn straight I have recharged over a hundred batteries multiple times and I have never seen either fire or explosion. I have had an ocassional battery fizz fluid which is itchy to the touch and I would not want in my eyes. If damage is done to the contacts by the fluid it is possible to refresh them with steel wool. The batteries can not retain as large a charge each time and incrementally decrease. The ocassional battery goes completely flat on me too early. I would not try recharging ordinary batteries with a charger meant for "rechargables". I have managed to save several hundred dollars.

RichardBond (talk) 03:44, 8 August 2011 (UTC) My results with about 5000 cells have been the same as Richard Bond. Non-rechargable cells of all types can be recharged almost as successfully as those designed to be recharged. I typically bundle D cells and AAA separately in parallel of about the same no load voltage. Up to 3 C cells surounded by AA in a bundle, then stack the bundles with aluminum foil between the bundles, usually 4 bundles high, then a small 6vdc wall wort charges up to 50 cells simultaineously. Individual attention gives only slightly better results. I don't charge them, if they are design voltage or more. Rechargeable cells get mixed in with slightly higher voltage non rechargables, as rechargable cells can tolerate faster charging. AAA get charged less than one hour. D cells about 8 hours. C cells and AA in between depending on how many are in the bundle. Neil — Preceding unsigned comment added by 24.127.242.99 (talk) 01:25, 13 October 2011 (UTC)

How it works
Some things to consider for the "how it works" section,
 * 1) During recharging, zinc tends to form dendrites rather than replate evenly. This is the main reason for the reversing polarity pulse charging technique as it decreases the size of the dendrites so it's better but far from perfect.
 * 2) Alkaline cells gas during use, which is due to the water content in the electrolyte becoming split into oxygen and hydrogen during use. This makes the electrolyte drier, and increases the pressure inside the cell. The gas can also form minute bubbles on the separator. Any gas produced will not be reabsorbed. A drier electrolyte and bubbles in the way of the separator is what mainly increases internal resistance during use.

Alkaline cells gas somewhat more when subjected to any sort of abuse, such as recharging. Any gas produced will not be reabsorbed. Gas bubbles accumulated on the separator are difficult to move out of the way. The recharged cell will often have the hightened internal resistance of the previously dead cell, but with higher open circuit voltage. Recharging will cause an ever increasing pressure inside the cell and hence pressure that puts the seals at greater risk of failing.

66.114.93.6 (talk) 08:51, 30 November 2009 (UTC)

Can we give concrete recommendations?
Kudos to the previous "How it works" discussion comment, finally what seems like usable information here. (Would be nice to cite sources though.) I'd like to see the webpage developed into something usable, with suggestions for a a simple charger and a leak proof box where the batteries are permanently stored. Far too many alkaline batteries going into landfills, and many in this world cannot afford NiCad/NiMh/LiPo to run a reading light or radio. The chargers linked to are just constant current chargers, a voltage source and current limiting resistor would be much simpler and work just as well. The web page speaks of a 40 to 200 Hz pulsating charge current, 80% on. The previous "How it works" comment suggests reversing the charge polarity, which is quite different. Judging from web postings, there are some moderately successful commercial chargers out there, but no information on charging algorithms. Anyone have any real information on this? Should the charger be pulsating, or polarity reversing? How fast? At what current, relative to the mAh of the battery? When do we stop the charge? If we charge slowly, can we keep it simple and just use a timer? Does any extra charge time even at low charge currents create additional gas with nowhere to go? Is a constant current charger suitable for use on at least some brands of alkaline batteries? Is there an easy way to determine the current state of charge of a battery? Is there an easy way to quickly determine if a battery will hold a charge? And if you have answers to any of these, can you cite sources? Jeriberi (talk) 19:18, 31 December 2009 (UTC)

The means of determining battery charge and charge holding ability vary between the different chemistries. The cheap method is to estimate the state of charge from the terminal voltage. The common method used for large capacity lead-acid batteries is to measure the terminal voltage under a known load. More accurate variations include using a light load to stabilise the battery, followed by a heavy load of short duration to assess the amperage the battery can supply (Ford US Patent). SLA banks for UPS, etc are assessed from the response to an applied square wave pulse. In other words, the impedance (frequency variable resistance) of the battery bank is checked. Unfortunately the results are not easy to assess, the effects are matched against known charge/discharge curves from the battery manufacturer and from prior readings from the same bank. Significant change in impedance values from known/prior values indicates an end-of-life condition. In the case of NiCad/LiPo/NiMh batteries, manufacturers are commonly using a charge accounting method, the total of charge extracted from the battery is recorded and compared against previous charge/discharge cycles. Most of this information is verifiable from the datasheets of battery management chips and SLA testing equipment websites. — Preceding unsigned comment added by 188.222.99.79 (talk) 14:29, 11 November 2011 (UTC)

Merge proposal
I would like to suggest merging Rechargeable alkaline battery with Recharging alkaline batteries as they deal with very similar subjects. 86.112.51.161 (talk) 20:28, 8 October 2010 (UTC)

Move proposal
The entire article reads more like a how-to guide, which is counter to long-standing Wikipedia policy (Wikipedia is not a manual, guidebook, textbook, or scientific journal). It either needs to be moved to Wikibooks or reduced to a set of a few footnotes in one of the other battery articles in Wikipedia, as suggested in Merge proposal, above. &mdash;QuicksilverT @ 19:18, 21 February 2011 (UTC)

Merging this idea (which is against all battery manufacturer recommendations) with rechargeable alkaline batteries (which is a proven safe technology) does not make sense. It could validate this potentially dangerous procedure and diminish the qualities of true rechargeable alkaline technology. —Preceding unsigned comment added by 63.124.122.173 (talk) 14:25, 22 April 2011 (UTC)
 * IMO, the lack of *any* citations after years of scrutiny, and the dangers of re-charging suggest that if noone can or will find any sources to back-up the claims here, the article should be discarded. The argument about cost (immaterial to the article, and also unsubstantiated - the whole article as it stands is original research) is no argument at all. Yes, NiCad's and NiMH cells have a high up-front cost, but I'll guarantee you from decades of personal experience that you'll get many (5-7) years of nearly continuous use out of them ... in the long run, much cheaper and easier on the environment. Twang (talk) 01:33, 29 May 2011 (UTC)

There is a difference between "Recharging Alkaline Manganese" batteries and "Rechargeable Alkaline Manganese" batteries. The former is a slightly hazardous technique (battery leakage and possible gas explosion), the latter being a battery specifically designed to resist the hazards of the former technique. I attest to never having ruptured either type of cell (PureEnergy/Duracell AA & AAA), but having caused both to leak. Modern batteries are designed to vent non-explosively, but there remains a low probability that this safe venting action fails. — Preceding unsigned comment added by 188.222.99.79 (talk) 14:01, 11 November 2011 (UTC)


 * A problem with this merge is that they're different techniques. Trying to recharge conventional alkalines with a PureEnergy or similar charger sold for recharging their own specialised alkaline cells will cause them to fail. There are two approaches to avoid this: using their specialist cells (as described in Rechargeable alkaline battery) or particular techniques, beyond those used by PureEnergy, as described in Recharging alkaline batteries. These are two different approaches. However the merged article now throws them together as if they're the same. Andy Dingley (talk) 00:04, 17 March 2017 (UTC)