Turn an old Maglite in a super LED lamp


26 Apr 2019

Big old Maglites are rather iconic and undoubtedly pretty useful, being handy, reliable and of great construction quality. However, there is one problem: they're old. And there is no better way to upgrade an old lamp than slapping a powerful LED bulb on it. And of course a little battery swap won't hurt.


I got this old 2D Maglite from my uncle. It was stored somewhere and he wasn’t able to even open the battery compartment, but a little challenge never discouraged me. Altough a bit old, it is a really nice and well built flashlight and we believed that to give it a new life it would have been enough to change the incadescence bulb with an LED one and maybe swap the D alkaline batteries with denser and more reliable (less prone to release toxic salts) lithium cells.

Oh, if only it was that easy…

I got a pair of big pliers and a couple of rags to not damage the red anodizing and, once opened, the hell was released.

Unfortunately, I do not have a picture of the leaked batteries before the beginning of the process that now will follows but, believe me, it wasn’t pleasant for the eye (nor for the nose).

Beware! working with old alkaline cells is unpleasant for various resons: in many occasions I had to stop because I fell dizzy and nauseos. I’m pretty sure that even if depleted this batteries can release some mildly irritating gasses. I advise you to use proper protection for eyes, hands and breathing. And absolutely make this outside! Believe me, this stuff is nasty.

Step 1: removing the leaked batteries

When alkaline batteries discharge completely, the chemical reactions inside them do not stop, but they can keep going in a destructive way. Hydrogen is produced, which will increase the pressure and make the battery swell. This will make the space between the cell and the inner side of the torch smaller, until the cell will press against the containervery tightly, making extraction pretty hard.

Not only that, but if the internal pressure is high enough, the cell case will break, and potassium hydroxide will come out the battery, forming potassium carbonate when in contact with the carbon dioxide in the air as a salt, that will make the cell adhere even more to the inner walls of our torch.

Lastly, the alkaline potassium hydroxide will also react with the aluminium, thinning the flashlight case. All of this make the removal of such batteries very hard… but not impossible.

The easiest: battery #1

The first battery was relatively easy to remove. For me it was enough to drill with a small bit in the housing, sticking a screw and pulling really hard with a pair of pliers. After 20 minutes of work, it came out in one piece, luckily. Now, I know that we are always told to not drill holes in or puncture batteries, but considering that these are alkaline and not lithium, and that they have been discharged for years, I didn’t really bother too much with it.

It might not look safe, but it is

The small bastard: battery #2

That was a lot harder, I didn’t have a screw long enough to confortably grab it with a plier, so I have followed this little trick. However, that worked only up to a point as you can see…

You can see another hole, a previous failed attempts

Now stuck inside the flashlight is a swallen battery with no cap and a lot of nasty stuff inside, and there is only one thing to do… I got a screwdriver and I started scooping out all of this white, black and pink poweder (that that should be respectively zinc oxide, manganese oxide and potassium carbonate) and once it was empty, prying with the help of a hammer the sides of the cell.

Once it was crumped enough and after a good our of prying, I was able to finally remove this second battery, it wasn’t easy but now the hardest part has come

That's how I had to beat up the battery in order to take it out
Nothing better than a toxic mix of metal oxides, petrol oil and vinegar for your lungs

Some tips

Before attempting to remove any cell, doing these things can make the process easier

Step 2: cleaning the mess

Step 3:

Last edit: 09/04/2019