[Mr. K]

if i recall there was a battery charger on the market that was supposed to work on any type of battery

like 10 years ago

I dont recall any explosions

I think there was just not a big market for it (expensive)

[Mr. K]

oh- and there is a you tube video online about what is inside once of these

it is a bunch of AA batteries (like 18 of them, I think)

they cut one open and show it

[erikm88]

Generally, it is not advisable because the chemical reaction for an alkaline battery is vastly different than that of a NiMH or other type of rechargeable battery. An alkaline can be recharged, but you won’t get the same charge/recharge cycle as you would a true re-chargeable battery.

[MachIV]

I’m familiar with those large block sized batteries you are describing. I’m not sure about charging specifically those, but I know as a kid in the 70s, we recharged in a regular battery charger all kinds of batteries including alkalyne that were technically not suppose to be recharged. We had a charger for D, C, AA, AAA, and 9 volt batteries. We recharged many a battery numerous times over. I only remember one or two times when a battery buldged out and none of them ever leaked or exploded, but I suppose it could happen at any time.

[mamelukesabre]

When I was a kid I recharged them all the time. Not just alkaline batteries but also regular non-alkaline non-rechargeable batteries. I’m talking hundreds of batteries each recharged tens of times. Eventually they stop taking a charge and you throw them away. Seems like if you let them get too hot, they are ruined and will not take a charge anymore.

Here’s a little secret for ya...

They were selling battery chargers for D cell through AA cell batteries WAY WAY BEFORE THEY INVENTED RECHARGEABLE BATTERIES.

Think about that.

I had one from radio shack. It had a slot for the little 9 volt batteries too. When have you ever heard of a rechargeable 9volt battery?

[Vigilanteman]

There is a reason that Alkaline batteries tell you not to recharge them. I don't know the reason for sure.

Neither do I know exactly what would happen if I lit a cigarette while filling my gas tank. And I don't intend to find out.

[E. Pluribus Unum]

Only rechargeable batteries are rechargeable.

I use Sanyo Eneloop rechargeable batteries. They are your best bet.

[reg45]

Ray-o-Vac tried to market rechargable alkaline batteries a few years back. They were not very reliable. It would have been a good product, if it had worked. You needed a special (expensive) charger which had a negative return on investment. I tried to make it work, but most of the batteries failed after fewer than ten charge cycles.

[discostu]

You can do it but it’s not the best plan in the world. They like to make gases when being charged, gases which be very much not your friend if produced too fast.

[Gay State Conservative]

I’m no chemist but I’d never try to recharge any battery that’s not specifically designed to be recharged.

[ansel12]

This LED drop in will extend your battery life.

http://www.amazon.com/Dorcy-41-1644-Lumen-Volt-Replacement/dp/B003MP8MGO

[Tupelo]

I doubt if it will work but ....................
I think your 6-12 volt automotive charger is overkill for this. Most of these put out something like 10 amps which is too much. If I were going to try it, I would purchase a Battery Tender Jr in 6 volts. These are what is known as a float charger and only put out about 3/4 amps and will not over charge the battery. Plus the little green light will tell you when the battery is fully charged. Plus it will maintain the charge without over charging the battery. Charging time will probably be about 10-12 hours but if anything will work this will.
Battery Tenders are available at most auto supply stores and motorcycle shops. I use them on my motorcycles and know they work for that and I think they may/might/maybe work for your use.
Hope this helps.

[glenn1]

Not worth the hassle to attempt recharging one IMHO; 6V latern batteries only cost about $6 new on Amazon or less than $10 if you want to buy one at a brick and mortar store like Walmart or Home Depot.

[smokingfrog]

http://www.dorcydirect.com/p-26-41-4291-65-lumens-led-lantern-black.aspx

[Squawk 8888]

Many hobby shops sell high-capacity D cells (~6AH). Open up the dead battery, replace the cells and you’re good for at least 1,000 charge cycles. As a bonus the capacity will be at least double what you’d get from fresh alkalines.

[Family Guy]

Here are some 6V batteries for $3 each online.

http://www.batteryjunction.com/6voev12labas.html

[backwoods-engineer]

Throw that piece of junk away, and buy an LED flashlight.

The $30 Streamlight Pro-Tac-1L that I keep in my pocket puts out 110 lumens for HOURS on one lithium battery, whereas those 6V lanterns with incandescent bulbs rarely put out more than 50 lumens. And I can use rechargeable lithium batteries that can be recharged hundreds of times.

[Arrowhead1952]

Years ago - in the late 60s to early 70s - we had a solar battery charger for dry cell batteries we used on electrical fences. It would keep one of the 9 or 10” long and 2 1/2” wide batteries for months at a time. It was just a trickle charger, but we used one battery for full a year.

[Eugbug]

I am charging three alkaline AAs at the moment with a current of 65mA. I had them on charge for 4 hours last night and they have been charging for 8 hours today without getting warm. If you get one of these battery holder devices which can hold 3, 4, 6 or whatever cells in series from suppliers such as the Chinese Dealextreme.com, you can charge multiple AAs in series. This is the first time I ever tried this and my batteries are in an explosion proof box! (A butter container + scrap of thin plywood to act as a baffle!) So what if they explode, all that can happen is corrosive potassium can be blasted around the place. I am doing this outdoors in a workshop and not too worried what happens.

There is a circuit here and funny account of charging batteries here: http://www.afrotechmods.com/reallycheap/batteries/batts.htm