# Charger for regular batteries (1960's/70's) **URL:** \ **Category:** Factual Questions\ **Created:** [June 19, 2024, 12:24pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047 "2024-06-19T12:24:06Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [June 19, 2024, 12:24pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/1 "2024-06-19T12:24:07Z")
When I was a kid back in the 60’s/70’s my Uncle had a battery charger that would allegedly recharge regular batteries like Evereadies. It had a special slot for 9 volts and could also fit sizes as large as D cells. It was used especially for toys my cousin had. I don’t remember it working very well and my Pop always said it was horseshit (his words) and might even be dangerous. But my Uncle swore that it worked and that he was saving a ton of money on batteries. Meanwhile my cousin always had toys that didn’t work per my memory. Anyone remember this device? It was a scam, right? Can’t charge regular batteries with electricity, right? ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [June 19, 2024, 12:36pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/2 "2024-06-19T12:36:59Z")
It was not a scam, you could even build one yourself. I did as a senior in high school and did tests on it under an exhaust hood for my science lab class. But it was indeed dangerous. - it caused gas to be generated that would cause the electrolyte to leak. The electrolyte was of course corrosive (battery acid) - The battery would overheat and occasionally caused small explosions and/or fires. - it can only be done a few times anyway as there was some sort of chemical change that charging would not undo. Sorry I can’t be more exact, I was a senior in High School about 40 years ago. When it worked, it worked pretty well. I recall taking a battery up to about a 90% charge. It was safer to charge a weak battery than a dead battery. I recall the percentage of charge dropping significantly each time after the first. The risk of electrolyte leak increased also. I only had one battery make a small explosion. None caught fire, but this was me, one kid and a few friends and not a test lab. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [June 19, 2024, 12:59pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/3 "2024-06-19T12:59:19Z")
The chemical reaction for all batteries is theoretically reversible. This includes the older “non-rechargeable” zinc-carbon batteries and alkaline batteries. The problem with trying to recharge batteries not designed to be recharged is that when you reverse the chemical reaction, the original chemical reactants don’t end up exactly where they should be and in the right form. For example, the anode of a zinc-carbon battery is the battery case itself which is made of zinc. As the battery discharges, you are reacting away the case itself. Reversing the reaction would require redepositing zinc in precisely the right area to maintain the integrity of the case. In addition, applying a charging voltage to a discharged battery often results in some electrolysis of water that is present in the aqueous chemistry, resulting in the production of hydrogen gas. With no way to vent the gas in a non-rechargeable battery, the battery may explode when you try to charge it. The danger of explosion is exacerbated if the battery case has also been weakened. Note that both zinc-carbon and alkaline batteries leak if they are left alone long enough because the cases eventually corrode and leak. Trying to recharge them exacerbates this tendency, making it more likely the batteries will leak and damage the device they are powering. All in all, it doesn’t seem like a great idea to try to save a few cents. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [June 19, 2024, 1:06pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/4 "2024-06-19T13:06:29Z")
IIRC you could even get a few more minutes of life out of an almost dead battery by warming it. I remember adds for those chargers. which said it would only work one or two times on a battery. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 19, 2024, 1:09pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/5 "2024-06-19T13:09:44Z")
Exactly how I remember it. A battery would seem to be recharged, but not for very long. ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [June 19, 2024, 8:28pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/6 "2024-06-19T20:28:47Z")
> [@pkbites](#): > > It was a scam, right? Not unless the good people at Radio Shack lied to me. > [@What\_Exit](#): > > - it caused gas to be generated that would cause the electrolyte to leak. The electrolyte was of course corrosive (battery acid) > - The battery would overheat and occasionally caused small explosions and/or fires. That’s probably why Radio Shack went to the trouble of putting a lid on what was otherwise a cheap, no-frills battery charger. ---
**Author:** ![I.Dunno](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@I.Dunno](https://boards.straightdope.com/u/I.Dunno)\ **Post date:** [June 20, 2024, 2:10am UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/7 "2024-06-20T02:10:11Z")
I grew up in the 50s and 60s and my dad bought one of those somewhere along the line. My recollection is that it was an underwhelming failure. It would give a brief jolt to old carbon zinc batteries but they wouldn’t hold it long. Eventually they wouldn’t recharge at all. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [June 20, 2024, 10:28am UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/8 "2024-06-20T10:28:07Z")
> [@What\_Exit](#): > > The electrolyte was of course corrosive (battery acid) You are confusing battery types here I think. The old carbon zinc batteries used ammonium chloride as an electrolyte, which is only very mildly acidic. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [June 20, 2024, 11:12am UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/9 "2024-06-20T11:12:29Z")
> [@I.Dunno](#): > > I grew up in the 50s and 60s and my dad bought one of those somewhere along the line. My recollection is that it was an underwhelming failure. It would give a brief jolt to old carbon zinc batteries but they wouldn’t hold it long. Eventually they wouldn’t recharge at all. This was my recollection. Cousin would put a battery in a toy that was in the charger for a long time (over a day) and get maybe 2 minutes or so out of it (about the same as just letting the battery rest in a warm place in the house). . ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [June 20, 2024, 11:16am UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/10 "2024-06-20T11:16:39Z")
> [@Princhester](#): > > The old carbon zinc batteries used ammonium chloride as an electrolyte, which is only very mildly acidic. He is probably referring to alkaline batteries. The electrolyte (typically potassium hydroxide) is corrosive. It’s technically a base instead of an acid, but a lot of folks commonly refer to any sort of corrosive electrolyte as “battery acid”. Calling it a “battery base” would sound weird. So, technically not correct, but ok for slangy use, I suppose. Alkaline batteries have a tendency to swell and leak when you charge them, and the potassium hydroxide makes an absolute mess of the battery connector in the device. > [@pkbites](#): > > Anyone remember this device? Simple trickle-chargers intended for Ni-Cad batteries were common in the 70s and 80s. There was nothing physically preventing you from inserting a carbon-zinc or alkaline battery into the charger. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [June 20, 2024, 11:30am UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/11 "2024-06-20T11:30:21Z")
> [@engineer\_comp\_geek](#): > > Simple trickle-chargers intended for Ni-Cad batteries were common in the 70s and 80s. There was nothing physically preventing you from inserting a carbon-zinc or alkaline battery into the charger. This was the mid-late 60’s and very early 70’s. And the charger was specifically marketed to be used on standard batteries, per the box. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [June 23, 2024, 1:55pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/12 "2024-06-23T13:55:22Z")
I could swear, and this is going on fuzzy memories, that Radio Shack sold two types of chargers even back in the 80s, one for regular batteries and one for NiCads. My memory is that the regular batteries were red and the NiCads were blue.Memory and age being what it is, this may be a completely jumbled memory, but it is what I remember. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [June 23, 2024, 2:05pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/13 "2024-06-23T14:05:03Z")
Well, looking at eBay, it seems I have the colors right, but I can’t find anyone selling regular battery chargers from Radio Shack, just vintage NiCad ones. Maybe this is a Mandela Effect memory for me. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [June 23, 2024, 2:19pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/14 "2024-06-23T14:19:30Z")
Wait! This is what I was thinking of. It was red batteries and green batteries. Cannot use for alkaline, but okay for general purpose. The standard NiCad charger was blue: [![](https://www.rfcafe.com/references/popular-electronics/images8/archer-radio-shack-battery-charger-23-120a.jpg) ](https://www.rfcafe.com/references/popular-electronics/images8/archer-radio-shack-battery-charger-23-120a.jpg) ---
**Author:** ![Icerigger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icerigger/32/432_2.png) [@Icerigger](https://boards.straightdope.com/u/Icerigger)\ **Post date:** [June 23, 2024, 4:19pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/15 "2024-06-23T16:19:21Z")
We had one, I went through a lot of C Batteries for my GE cassette tape recorder. It sort of worked, each charge would last less and less. > **[Vintage GE General Electric Model M8433A Portable Tape Recorder | eBay](https://www.ebay.com/itm/164880855582?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=164880855582&targetid=2295557532670&device=c&mktype=pla&googleloc=9015298&poi=&campaignid=19851828444&mkgroupid=160536780385&rlsatarget=pla-2295557532670&abcId=9307249&merchantid=113597888&gad_source=1&gclid=Cj0KCQjwj9-zBhDyARIsAERjds29RbVrsdkC0OjExZYxCmTBtj2AcFwqNRwKw7INXeKZqiqIB5NMKPEaAhP-EALw_wcB)** > > See title and pics for description. Tape player is in beautiful cosmetic condition. Looks barely used. Clean battery compartment. Box is garbage and will be thrown away unless buyer specifically asks for it. I tested the player and it plays a... ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [June 25, 2024, 2:39pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/16 "2024-06-25T14:39:16Z")
> [@What\_Exit](#): > > it caused gas to be generated that would cause the electrolyte to leak. The electrolyte was of course corrosive (battery acid) If it was one of the old-style carbon/zinc batteries there was no corrosive acid involved. At the instruction from the Golden Book of Chemistry Experiments I used to take old batteries apart all the time. The ends of the battery were zinc discs (in really old ones, you had a complete zinc cylinder), there was a carbon rod running up the center, and the battery was filled with a crumbly paste that was mostly manganese dioxide. You could use all of these items in home experiments. No acid involved. See page 25 for how to disassemble and use an old battery: > **[Brent\_GBC.pdf](https://library.sciencemadness.org/library/books/Brent_GBC.pdf)** > > 41.39 MB I agree that recharging (running the battery “backwards” can result in depositing zinc where you don’t want it and it doesn’t help, so you can probably only do it so many times. I never tried taking an alkaline cell apart, or a NiCad battery. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [June 25, 2024, 7:16pm UTC](https://boards.straightdope.com/t/charger-for-regular-batteries-1960s-70s/1003047/17 "2024-06-25T19:16:37Z")
Definitely not what is being sought in the OP, but in the 80s or early 90s Rayovac had rechargeable alkaline batteries. There was a special charger, and special batteries. Due to an extra conductive ring on the positive electrode, only the special batteries could be used in the charger. I recall they worked as well or better than the NiCd batteries of the time, but perhaps at 1.5 volts instead of 1.2 volts. They were not as good as the NiMH batteries that became common a short time later.