Technology as a way of life

Life is the art of drawing without an eraser...

Well first of all i have to warn everyone that there is a small risk of attempting to recharge a non-rechargeable battery: possible leaks (which are highly toxic or even burn you charging device).

Now that the "don't blame me if you arson your house by accident" part is over we can continue:

Taking a normal AA or AAA battery and putting it in a normal battery recharger is the "hardest" part of the experiment. The slow recharge rate is preferred (around 64-100 mAh) because the slower the recharge the better chances it wont leak. Anyway it's reccomended that you don't leave the charger unsupervised for long periods of time (over 2 hours) and unplug it for 10minutes if the batteries are getting warm.

The small standard batteries AA and AAA are no problem to fit in any charger but what if it doesn't support 5v/9V/12v batteries? Well then we need something else to tranfer a steady supply of curent through them. I guess everyone uses a device called a Transformer to recharge their mobile phone/mp4/iPod etc.

On the top side lies a little sticker with a few specs. Most important is the output. For charging a 9V battery any transformer with an output between 9-12V is good but the max mA(h) (micro amperes per hour) should be kept under 400 for safety reasons cause the battery may get too hot, leak and ruin your beautiful table (or wherever you placed it). As you can see below the Voltage is good (12v) but the Amperage is way to high (1670mA) which would cause it to leak in less than 30minutes. I don't recommend using your phones charger or any you actually need in top condition because there is a a very small risk to burn it. Use one that lays around in a drawer somewhere from some old appliance. The wiring may be tricky and not too advanced but it does it job. Use wiring to connnect the inner hole to the "+" sign on the battery and the outer metal layer to the "-" sign (dont ask how to keep them in place, be creative or use ductape like i do hehe).

So let's plug it in and charge it in small periods of time (1-2 hours) a few times (4-5 times). The battery should be in a working state and around 75% of the original charge (if you have a multimeter check the voltage on it).

So i did my own experiment using 2xAA Alkaline Energizer batteries. They were used in my wireless mouse until the mouse died (with a charge around 0.50v and 3mA they were heading for the trash bin). I put them in the charger and left them in for 2 hours with a 5 minute break. I repeated this cicle 5 times. At the end i left them on the table for an hour to self stabilize the current. When i checked them with the multimeter i was pretty impressed. A voltage of 1.32V and around 135mA (the standard batteries i buy have 175mA). I am using them right now in my wireless mouse and they work just like other battery. I will have to see if they last on the long run (2-3weeks) because i usually change them once a month.

The warnings on the battery labels are a bit exagerrated because the battery is very unlikely to catch on fire, maybe just leak (the liquid is very corrosive and may damage the device) if recharged.


2x AA Energizer 0.5v @ 3mA (before charge) -> 1.32v @ 135mA

1x 9V Toshiba 0.29v @ 10mA to (before charge) -> 8.22v @ 320mA

The most important things you have to remember are:
- outputs of max 180mA can be unsupervised for max 4 hours in my experience (but the quality of the battery is important too to prevent leaks)
- outputs over 200mA (max 500mA)can be unsupervised for around an hour or two (just check if its too warm, if not it should be ok)
- don't let the battery get hot (unplug it and let it rest 30minutes) and retry
- don't try recharging extreamely cheap batteries or those which are not alkaline (the quality is doubtfull and may leak within 20-30minutes)

Well it's REALITY, and i will keep you updated on how they are performing...


Anonymous said...

A really safe way to recharge a "non" rchargeable Alkaline battery is to use a Battery Xtender which I have effectively used for years. First of all its designed to do just that, recharge regular disposable Alkline batteries and more.
You can find it at

RaduB. said...

yes true but the point was to do it with stuff laying around the house. That thing is around 40$. It costs nothing to recharge my way (maybe a cheap 5-7$ charger).

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