TenergyCombo: 4 pcs Premium D Size Rechargeable Batteries High Capacity 10000mAh NiMH - UL Certified

Use them in a “very active” motion light. Last about a month before recharge. Love em.

I use them in an electronic cat door, and they outlast regular batteries before needing re-charge. This is great because changing the batteries in this door is a pain. The product is exactly as described. I expect they will easily pay for themselves plus reducing waste/garbage.

Of course the seller of any product nowadays wants you to give a review on what experience you had with it, and whether you classify it as good or not. As far as rechargeable batteries are concerned, the only way to truly classify their performance is by the long run and is difficult to do so when they are brand new. Why did I chose these batteries ?? Because of T-Energy's reputation and years of their dedication to making rechargeable batteries. I had already bought six T-Energy Premium AA batteries to power up a game trail camera designed to take pictures, time lapse, and video. Those have performed flawlessly when left out there in the woods, miles away in all sorts of weather, to do their job. T-Energy had already advertised a while ago that they were going to come out with a version of their batteries known as Premium. I decided to give them a try with those AA's even though they were not classified as low-self discharge. I am almost 100% sure these 'D' version batteries would do the same. They were bought due to an unexpected Easter trip camping this past April 2019, where I needed eight 'D' sized to power up a number of battery operated lanterns. They did their job superbly well on this three night camping trip. Although they operated for a small number of hours each night while camping, they have not - to this date and as of this writing, needed a recharge. They were not given a full discharge or cycle because there was no time. They were given a simple recharge when they arrived. Mysteriously their terminal voltage only went up to 1.40 which was quite odd. I believe this was due to the fact that they still needed this rejuvenation cycle where they have to be fully discharged, before being recharged all over again. And it appears that this needs to be repeated a number of times to get over what I classify as the 'break-in' phase. Again - too early to tell as far as their performance is concerned, but with T-Energy's reputation and the fact that these are classified as 'Elite' in performance, I feel confident they will do a great job in the days and years to come. Will give any additional updates as time goes by in case their performance goes awry.

I bought four D cells 4 months ago and one of them has began to error out on my charger and will not accept a charge. They are supposed to have a 12 month warranty but I can find no way on the Tenergy website to contact them about the warranty.--Update: I found "customer service" on their website and contacted them about this issue. They sent me a new "D" cell as a replacement and offered the following advice:One thing we would recommend especially when using batteries with light candles/LED decors is to charge them up right away as soon as you see them low, as they can be easily forgotten and the lights will continue to draw current from the battery.Generally, rechargeable batteries are not recommend for light candles/LED decors due to the device over-draining the batteries often.If batteries are very low and left that way for long periods of time the batteries can go below 1.0V which increases risk of lowering battery life or permanently damaging the batteries

Great