USB Rechargeable Lithium D Batteries - 1.5V / 4000MAh (2-Pack) - ECO-Friendly & Recyclable - No Memory Effect - Not NI-MH/NI-CD/Alkaline Batteries Review

I'm mostly happy with these. The only con I've seen is that they have some connection problems. They don't seem to be exactly the same size as a D cell, so they wiggle around (in a mag light in my case.) This causes the connection to be intermittent unless I adjust the spring in the base of the light to make it a tighter fit. If I buy more lion batteries, I'd definitely move in the direction of the ones with a micro USB charge porton the side instead of these that have a removable cap and full…

I really like being able to recharge the batteries via a USB port. I utilized the batteries, in a aerated live bait bucket. Once charged they lasted approximately 72 hrs. non-stop before losing charge.

I purchased these for a microchip cat feeder that says not to use traditional rechargeable batteries. After trying another brand of lithium C batteries that didn't work, I purchased these. So far they are working and the sensor is working the same as it was with alkaline.

I chose them because it had the correct voltage. I installed these batteries on my battery powered radio. The batteries caused so much noise as to make listening next to impossible. When I replaced these batteries with another set the noise suddenly disappeared.

I have a high end AM radio I use to pick up far away stations. AM radio is subject to interference from all kinds of things; electric motors, lightning, some car ignition systems, etc. These batteries emit an interference signal making AM radios not usable. I didn't fully test them beyond that. They probably work well in other devices.

These batteries maintain a high voltage output until almost dead. Slightly more than 1.5v at full charge. Great so far.

I have two problems with these batteries. Charged for 10 hours. When tested, showed 1.48 v. No wonder they die so fast. Secondly, the negative pole of the battery is too small. About the size of a shirt button. (No picture of this side of the battery in the advertisement.) The spring on my mag light flashlight is to big to make contact with this small pole.

The batteries came charged so by the time came to recharge them, the warranty was up and it wouldn't take a charge, most expensive 1-time-use-only batteries i have ever purchased! If you do buy these, test that they charge ok on arrival! Don't get screwed out of $25 like i did😡

So far, so good. Bought them to work an outdoor motion light. Alkaline batteries do not do well in the cold. These work well so far.

They are great battery's but don't trust cap on top.If that little rubber band breaks for so reason and you loose the cap the battery is shot.HARLAN

Hopefully the listed recharge cycle is accurate because after first use I am not impressed. I am using in a fan in my small heated ice shanty. They only lasted 1/2 a day when your typical Duracell battery lasted me several days. If they do hold up to recharging often it will eventually save me money but I was expecting more from it after using other lithium iron batteries in other devices.

Saving money. and actually people are mind blown to see it is usb when I show them. Works great in a maglite flashlite , and also worked in a boombox I have no problem. Lasted several hours in the boombox. and the flashlight god knows how long it will go. surely days or more like regular D batteries. I haven't had to replace the flashlight batteries yet.

Using four of these pieces for a maglite (d cell unit) poorly powers (after fully charged several times and discharged) producing a pathetic glow. The idea is great, the product promised is even better. The result - well, kind of a bummer. I would not recommend these to anyone after my experience.

These D size batteries last a long time in my lantern. In six months, I have charged them once. One takes about 10 hours to charge with my "Tripp Lite 4-Port USB Charging Station with OTG Hub", I used the 2-amp/ 5-volt outlets. A red light shows when they are charging and the light changes to green when it is fully charged. The cap is held next to the body by a short rubber band covered in cloth. They are nice because they store SO much energy.