Dlyfull B4 Universal Battery Tester ZDNET's key takeaways This battery tester handles a massive array of batteries, from one-use alkaline batteries to rechargeable cells.
It's quick and easy to use, and can be used to test whether rechargeable batteries have come to the end of their life.
The small display can be hard to read. View now at Amazon
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I've lost count of how many times I've seen someone throw away good batteries. Man, those things cost money, and it's so wasteful. But it seems to be the first thing people do when something isn't working.
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Before I toss a battery into the recycling, I always test it. I generally use a multimeter, but that involves knowing what the voltages of a battery are when they're full and dead, so unless you have a brain that remembers stuff like that over people's birthdays, this isn't a practical method.
But fear not, because I've found a really cool battery tester that's easy to use, accurate, and can be used with virtually any battery you'll find around the home -- both one-use and rechargeable.
And when I say pretty much any battery, I mean just that. The Dlyfull B4 battery tester works with 1.2V Ni-MH, 1.45V zinc air, 1.5V alkaline, 3.0V lithium manganese, 3.2V LiFePO4, 3.7V Li-ion, and 6.0V, 9.0V, and 12.0V Alkaline packs. It is compatible with AAA, AA, C, SC, D, N and PP3 sizes, as well as a whole range of button cells, including CR123A, CR-V3, 2CR5, 23A, and 27A.
The Dlyfull B4 can test a lot of different times of battereis. Adrian Kingsley-Hughes/ZDNET
The device itself needs two alkaline AAA batteries to work -- and a set are provided to get you going.
Using the tester is easy. The hardest part if figuring out which slot fits which battery, because if you get it wrong, it'll give you an inaccurate measure of how much power remains. Once you've figured out where your battery goes, push the positive end into the slot and use the probe to touch the other end (button cells slot into the tester in such a way that you don't need the probe), and the LCD screen will show you the voltage, remaining capacity, and a level bar display.
The tester is easy to use and the results are easy to decypher. Adrian Kingsley-Hughes/ZDNET
It's so simple that I can do it single-handed and take a photo. I used this the other day to go through a pile of batteries left for recycling at a store, and out of the 50 or so batteries left, more than half were less than 50% discharged, and had plenty of life left.
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You can also use this to test to see if rechargeable batteries are at the end of their lives. Fully charge one and see what it says on the meter -- if it shows less than 80% charge, the rechargeable battery is at the end of its life and needs replacing.
ZDNET's buying advice
For $30 (at the time of writing, there's $5 off the price), I think that the Dlyfull B4 battery tester is a good buy, especially for those who are still using a lot of disposable batteries in things like remote controls, game controllers, flashlights, radios, and other such items, because this is going to save you money. Too many batteries are being thrown out when there's nothing wrong with them.
If you don't want to buy a tester, then try taking the battery out and put it back in. Sometimes the problem is as simple as a poor contact between two batteries or the battery and the contact (this is why my grandma always used to open the battery cover and give them a roll before condemning batteries).