Lithium batteries for cordless power tools are not cheap. Frankly, I have better things to buy for $50-100 than a stinking battery.

The relatively new “Smart-Chargers” have cost me well over a hundred dollars, by my own estimation, just in the last year. Have thrown away at least one, possibly two, lithium batteries for my cordless stuff. I recently watched a video on how to “revive” a lithium battery. I already knew my old 9V lithiums never went bad, but they had “dumb” chargers on them – they are still going fine after 6 years.

As it turns out, the “Smart-Charger” senses the existing voltage within the lithium battery. If it is below a certain threshold, it refuses to charge the battery and gives you a “faulty battery” warning. Even the PC board in some batteries seems to go wonky and fail the batteries out, even when each test fine individually. I always took it as a given that the “Smart-Chargers” were there to help you maintain the battery life – one would think that, given their generic name containing the word “Smart”, right?

Not so. If the voltage falls below about 2VDC, the battery is likely still good. It’s just that the “Smart-Aleck” charger refuses to send a charge in order to “protect” the battery. Now, if it is going in the scrap heap, and I have to fork over $50 bucks or more for another, it’s worth a little research. I followed this link: ( and watched the video.

I then went home, and connected the mostly charged “good” battery to the “dead” one using alligator clips. Like the video, I connected positive to positive, and negative to negative. I let it sit there for an hour, and wonder of wonders – when I put it in the “Smart-Charger”, it now charged it fully. Both of the “dead” batteries have been running just fine for over a month after performing this little trick.

It boggled my mind, until I imagined how much money these companies are making selling their proprietary batteries to consumers who do not know this little trick. And I have been hopping on one leg and kicking myself with the other for not realizing this, a feat in itself with my new knee and hip joints. I should have caught this just by virtue of having my old “dumb”charger always able to crank my 9VDC batteries back up for years, while the “smart” one seemed to fail my 18VDC batteries every year.

Suddenly it makes extreme marketing sense – and that is how things work. If you can sell it as “smart” or “intelligent”, the assumption is made in your mind that it ‘must be even better’ than the older ones. It certainly is better, but not for us, the guys who actually buy these batteries. It is extremely good for the purveyors of each of these proprietary batteries – they are selling battery after battery to guys like me, who just didn’t snap to their game.

The amount of waste generated by these “dead” lithium batteries is big, but when you take them to a recycle center, they don’t give you a buck for them. In some places, they want to charge you to handle them, and that is even worse because many if not most of these batteries are fine. If not, then the lithium is recycled but you get zilch for your efforts other than knowing it isn’t in a landfill. Which is nuts in itself, because lithium is a mined product – it comes from deposits in the ground already.

If you have a completely dead battery, registering ZERO on your voltmeter, there is another video on how to revive these as well ( You do have to take the battery apart to do this, but if it is a $100 high capacity, then taking a few minutes is worth it. If you are tight with money like us, then it is worth it as well.

Hope this helps somebody save a few hundred dollars….


Don’t Get Outsmarted By Your “Smart-Charger”… — No Comments

Leave a Reply

Your email address will not be published. Required fields are marked *