Odec AA Rechargeable Batteries, 2450mAh Ni-MH Double A Batteries High Capacity 1200 Cycle with Storage Box (16-Pack)

Ok, So one thing that really made me question purchasing these batteries was the constant review saying "They are much bigger". Those reviews are correct but a little misled. This is what I found out from actual measuring. This was done also while comparing four other batteries. Here are the Measurements1. Energizer 1.977 x .5552. Duracell 1.978 x .5553. Rayovac 1.984 x .5554. Duracell ProCell 1.989 x .5555. Odec Rechargeable 1.985 x .570Now as you can see there aren't really huge differences, in fact when I measured other Duracells, Energizers and compaired them to each other I couldn't get an exact matching pair. I think this is in part to how they (Duracell Energizer and so on) wrap the AA battery. All batteries were off, but I'm only talking about being off .001 - .002.BUT Odec batteries are bigger. That much is true, but it depends on how you use them if it will really matter. If you are using them side by side you may have a problem because they are .015 larger in diameter compared to others. For most all my needs of these batteries I only have two side by side; which doesn't really cause a problem. They do fit. Now in an area that causes some problems is when I have to slide the batteries in length wise this causes the batteries to be wedged in and gets really tight.Devises that I dont have any problems withWireless mics, Motorola Walkie-talkies, Smoke detectors, Thermostats, and so onDevises that cause issues.Wireless in-ear monitors, and any device that i put 4 batteries side by side.All around the size isn't a big issue for me and I am testing out how long they last and how lng they take to charger. I bought a SunLabz 16 Bay Slot charger for these batteries. I will update with more info on the life of them later.

----- At unboxing: May 25th, 2018 -----The first 4 of my 16 pack ranted from 0.65 - 0.84 volts, as measured in my La Crosse BC-1000 charger. Considering the product information says they wont discharge below 0.90 volts, i'm mildly concerned. I'll post more as they go through testing.----- Next day: May 26th, 2018 -----The first 4 charged and i measured the remaining 12. Not a single battery was up to .90 volts which is stated as the lowest they will discharge. The 12 were ranging 0.62 - 0.89 with 6 of them in the .60 range. After they are all charged once, i'll Discharge/Refresh all of them then run capacity tests and post the results.On a side note... the plastic battery boxes they shipped with were a nice extra except for one problem, the Odec batteries are slightly larger than other batteries and it makes it difficult to release the catch and open the case. I tested other batteries and even my old Powerex Imedion cells which are larger than most fit better and there is no issue opening the box. I'll find a caliper later and post measurement comparisons. However, even just the 'box text' is a pretty good indication that these will have to only go into my more forgiving devices. I have some that inserting even the Imedion cells in is a struggle. These will never fit in those.----- After many analysis cycles: June 7th, 2018 -----I actually bought another analyzer because running many cycles for 16 cells takes so long. I added an Opus BT-C3100 to my collection along with an XTAR VC4, which is a charger only. I'll get reviews of both of those out in the coming days.I ended up running more than 6 full cycles on all 16 cells (some more but I didn't record those). I started with a few Discharge/Charge cycles on all of them then did Capacity Tests and mixed in a couple Discharge/Refresh cycles. I also changed up the current to see if I could improve the batteries performance. My normal practice is to do a 250ma discharge and 500ma charge. All my other batteries seem to like that (Enloop, Sony, Imedion, etc.) but the initial performance of the Odec cells was so bad I changed to a 500ma discharge and 1000ma charge (or with the Opus 700ma discharge and 1000ma charge) cycle. Ultimately I cant say that it improved anything (or didn't) but it did speed up testing, which took FOREVER.The end result is the cells leveled out at ~81% of rated capacity. I did a capacity test run on both the La Crosse and Opus analyzer to ensure they were in agreement and the average for both was within 2% variance.For some of the cycles, especially 2nd through 4th, the cells increased around 10% average capacity each time. The initial average across all cells was 36% of stated capacity. The final average of 81% was consistent across the last two cycles.I will admit that I don't have the patience to set aside some cells for Self Discharge testing. The sales materials do not say they are LSD, even though I see some people in reviews making that claim. One of the sales graphics states "the stable exist of hydrogen expand the space of crystal lattice, greatly reduce self-discharge of the batteries" However, the sales claim of LSD I do not see, only reduced self discharge. What does greatly reduced mean in numbers? I don't know.It is also worth re-stating that these cells are larger than most of my other AA cells. Like all other cells I measured, the Odec are fairly irregular so rolling them around in the caliper got width measurements that varied by about .25mm. this is similar variance to nearly every manufacturer I have measured and is not a ding for Odec, just a fact of life for cells. The Odec cells measure about 14.4mm which is very similar to my Imedion cells. I know from long experience that i have quite a few applications for AA cells where I simply can't get the Imedion cells into the device. That will be true for the Odec as well. For the Imedion cells they were capacity monsters... so I felt pretty good about the extra size. They routinely cycled capacity at 300+mAh over their stated capacity (really upset they are not sold now in AA format). With the Odec capacity coming in 20% under stated capacity, i'm not so thrilled with the size.How will they shake out over time... we'll see. I'll test capacity periodically and update here if they increase or decrease from the 80% plateau they have hit.----- Recommendation? -----If these batteries had been quoted at 2000mAh, for the price I'd be wholeheartedly all in. Half of mine still fall under that mark but they would be close. Maybe I'm spoiled. My 6yr old Imedion cells still all cycle above stated capacity and they are abused.As is, the Odec cells have come up to enough capacity to keep me curious. I'm going to keep them and see what happens in the mid and long term.Should you buy them? Well, read above and decide for yourself.

I have purchase many different AA rechargeable batteries in the last four years. I had been purchasing Duracell Rechargeable s in a small quantity at a time. So I was looking for a larger quantity at a fair price. So I have compared all purchases to those original Duracell batteries. After two years of use they started failing. This product was the first I purchased. Then I purchased additional batteries in the last year that were all from different manufactures. I set up a test because the 3rd set (3000mAh) only lasted three days. The Duracell (2400mAh) lasted 28 days, the bad Duracell lasted 5 days. I tested the 3000's three separate times. Really bad. A couple weeks ago I tried again. Tenergy (2600mAh) lasted 5 days. Tested multiple sets of them and they all tested at about 5 days. Went back to the old BAD Duracell batteries and go about 4 hours more out of them than the new ones. So I had to mention that these batteries lasted SIX WEEKS. They still last six weeks in the same test. Most cheap batteries are cheap garbage and at a minimum false advertising. These are the best!

I am SUPER impressed with the battery life of these little units. I had an occasion where I had to deliberately discharge the batteries to ensure a backup system was working correctly (flash unit for a wedding). After roughly 300+ charge cycles over an hour long period with no noticeable loss in recharge speed I decided I needed to try an easier method. Left the batteries in a child's toy that normally eats through batteries and left it in another room. After approximately an hour the dang toy was still going strong. Split the 4 batteries into 2 more powerful devices (decline to add more to keep the review family friendly) and after 2 hours the devices were still going strong. At this point I am completely amazed and had to give up and go to sleep. The batteries were discharged in the morning so I could perform my tests but I have no idea how long they ended up lasting. If everything else in the world were made half as good as these batteries we could probably end war and poverty. Ok... maybe that's a stretch but there'd be a lot less grumpy people in the world.