TenergyTenergy Centura 1.2V NiMH Rechargeable D Battery, 8000mAh Low Self Discharge D Cell Batteries, Pre-charged D Size Battery, 4 Pack

Well made.

Bought 4 of the tenergy 8000 mAh batteries. All 4 of them have a capacity in the 6000 mAh range, 6497, 6133, etc. I tested them twice just to be sure. My BT-2000 tester is accurate enough, (probably not good for a lab but home use is fine) and I've tested many batteries with this unit. I tried to return them but the system states they are not returnable. Beware! ( Called Amazon and they took care of the issue, excellent customer support as usual from Amazon. Seller... not wanting to take them back after less than 10 days, not impressed.)

The failure rate is questionable. 8 batteries purchased, 1 battery failed after 2 discharge and charge cycles. That's a 12.5% failure rate. Is that acceptable? I would say no.The batteries on a full charge seem to last longer than regular alkaline batteries, so the tradeoff might be worth it. instead of buying 16 batteries for $24 bucks at Walmart - equivalent to 2 charge cycles - I bought 8 tenergy at amazon for $46, with one battery going dead. That dead battery costs approx. $6.Just be aware that this item is not returnable, buyer beware.Update: 5/4/19I received assistance from Jerlynne at Tenergy Customer Services, who reached out to me and explained that although the batteries were past the warranty period, they would offer a replacement for the dead battery.I received the replacement today. Thank you.

I just ran the four Tenergy Centura D Size cells through my "generic" smart chargers (Dlyfull Pro and PS Power DC5000 which appear to be the same design) that have a test cycle that drains the batteries at 500mA and charges at 2000mA.The results for the four battery capacities are as follows in mA: 8171, 8703 9052, and 9189The great part is they all measured higher than the specified 8000mA typical capacity. Not many manufacturers' batteries do that.The bad part is that the consistency of the capacities is greater than 10%. However, it may be because of the difficulty that battery chargers have when determining the end-of-charge for NiMH batteries when charging at a low rate (even at 2000mA for these batteries it's only a charge rate of 0.25C)Longevity of the cells cannot be determined as this point since I've only had them long enough to do a test cycle in the charger.Low Self Discharge characteristics also cannot be commented on because I've not had them for long enough as well.

For Christmas I received a 6 d cell led maglite. I used regular Duracell that I bought brand new. Unfortunately the flashlite would act up and just randomly turn off.Almost thinking its a defect with the flashlite. We we called maglite customer service and were told the lite gets finicky when batteries are older or past half their life span.After doing some research on what to get. I found a youtube video on tenergy batteries being a good recommendation for maglites. I bought 6 of these and never had an issue with the flashlite. They last long too. A must get for maglites