Over the past few weeks we’ve looked at handy, and that make dropping screws less likely. This week’s tool, a desulfator battery charger and maintainer, can revive weak batteries from deep sleep.

This suggestion comes from Stephen, a reader and follower of this series, and honestly I’m surprised I hadn’t discovered one of these already. He uses a four-amp Viking model from Harbor Freight and reports fantastic results. The device has saved him from having to replace batteries on a number of vehicles.

If you’re one of the many Americans working from home right now, your car’s battery has probably gone belly up at least once. I know my batteries have drained to nothing a number of times since the pandemic began.

Unfortunately, if you let an old battery die you may not be able to bring it back to life by simply putting it on a charger. One reason for this is a condition called . When a conventional lead-acid battery operates in your car, on the battery plates. Over time, this chemical reaction will make your car’s battery less effective. One day, the battery will let you down when you need it the most.

Sulfation can be accelerated by a bunch of factors including overcharging, extended storage and yep, letting the battery die.

In my experience, what will then happen is that I connect the battery to a traditional charger but the charger cannot revive it. Or I’ll take the battery into an auto parts store to be charged, only for a similarly disappointing result. I have a Deltran Battery Tender four-amp charger at home and it just doesn’t work when I give it a really dead battery.

That is where a desulfator battery charger can save the day. These are different than your typical chargers. A desulfator charger determines your battery’s health and sulfation level, then attempts to restore the battery’s lost capacity. These devices usually work by using a high-frequency current pulse to loosen the sulfates and allow them to dissipate into the battery. If done well, these devices can extend the life of a battery considerably.

Check out this video from YouTube Channel — no relation, I think — for a review on this charger:

So the next time you’re looking for a battery charger, perhaps go for one with a little more tech backing it up.

These devices are sold just about everywhere. The four-amp Viking model Stephen uses can be purchased from for $30.

Do you know of a weird or unique but must-have tool you think every wrencher should have? Do you want to see us put a type of tool to the test and see how it performs? Shoot me an email or drop it down in the comments!

Updated 3/3/22 with new details.