Battery Tester for AA AAA C D 9V etc 12 Types & Household Batteries Checker

This DLYFULL B4 battery tester is a must-have if you check a lot of rechargeable batteries or any other type of batteries. I also went over the tester and used white-out with a brush, and then wiped excess off using WD-40, sprayed on a napkin, and it took the residue off (because it was hard to see the # displayed on the unit), leaving it with white numbers that you can see clearly. This is the best battery tester that I have used so far. I found this tester easy to use, too. If you're looking for a good battery tester, look no further. I found this tester to be very accurate and worth the price.

I love this tester! It tests so many different types of batteries! The pulse testing gives a much more accurate reading of what what's actually left in the battery. It gives a percentage read out that is far more helpful than a needle gauge. A similar tester is 4-5 times more expensive and doesn't have the LCD readout. If you need a battery tester, buy this one!

I had the B2 tester and it died after about 4 years of use. I liked it and decided to replace it with the B4 version. First, it's made well. Second, it's more accurate than the B2 version in that it shows percentage of charge. The B2 version only shows bars. I think both these testers are good value for the money. However, if you only really need to check AA, AAA, C, D and 9volt batteries, the B2 version is a lot easier to use because you don't have to use the probe tip on the B4 version. You just slip the battery in the right slot and you're done. However, I use a lot of different button batteries for various devices. The B4 accommodates them but sometimes you use the probe and sometimes you don't. It's a learning exercise. And testing the AA, AAA, C, D and 9v batteries in the B4 requires two hands. For the price I would buy both but don't have enough room on my work bench for both. I hope this helps others.

great gadget and will save you money. I have lithium batteries in my cameras. Lithium batteries can last an unbelievable amount of time but you should always know the life of it. I almost replaced mine at 3years only to find out they were at 45%!! this will save you some money. Batteries are still going and its been 5 years lol

I purchased this Dlyfull Battery Tester in Aug 2026. Right out of the box, the device kept giving an "error" reading. Even after replacing the batteries and trying new batteries for comparison, the same result; an error. Not worth your time

Easy to use and read results. Definitely value for the cost. So glad I found this on Amazon.

OK, although some battery types don't fit. A good VOM is probably just as good.

I read about this device in an on-line article since I was in the market for a battery tester. I can't count the number of battery powered devices in my house and when one of them stops working the first thing I need to check is the batteries. I have a battery tester that is part of a battery storage tray but it's very rudimentary and permanently attached to the tray. I needed one that I can take to the malfunctioning device. The article I read pointed to a device that meets this criteria. I ordered this one based on the recommendation in the article. When it came in I was ready to try it with a number of batteries I had put aside for the purpose of checking out this tester. I used it to check various battery types (AA-Alkaline, AAA-Alkaline, Ni-CAD, L-ion). The results confirmed that the batteries were generally in the condition I suspected they were in. The readings displayed showed the terminal voltage and the percent of charge remaining. I worked as an electronics engineer designing test equipment so I'm always looking for inadequacies in stuff like this. I can say I have 100% confidence in the tester. If you have a lot of battery powered devices, get one. I'm glad I did.