on October 18, 2009
I purchased a large number of AccuEvolution rechargeable D, AA and AAA batteries from RealGoods last year. Eight of the batteries I received were dead on arrival and they wouldn't charge in the AccuManager 20 charger, which I purchased at the same time. I sent those batteries back to RealGoods and received replacements. Over the next few months more batteries failed to charge on the same changer. I had over a 50% failure rate in the most expensive D batteries and they continue to fail. I had a fairly high rate of failures on the AA batteries, although no where near the failure rate of the D batteries. After three months RealGoods would no longer replace the batteries and they referred me to the manufacturer. The manufacturer agreed that my usage pattern should not have been the cause of the failures. I returned several of the D batteries to them and they stated that one of the batteries could not be charged and they had to wakeup the other two. In the mean time four additional batteries have failed to recharge (3 D batteries and 1 AA battery). I have also been using a lot of the Sanyo eneloop AA rechargeable batteries and I have had no failures so far on the same charger.
Since I first reported this problem, I ordered 8 D batteries from Tenergy and I now appear to be having the same problem with the Tenergy batteries. Two of the first four I tried to charge would not charge, but after leaving them in the AccuManager20 charger for a couple of hours, one of the batteries started to charge. The AccuEveloution manufacturer sent 6 new D batteries on 10/22/2009 to replace the batteries that appear to be failing. After months of testing and rotating various batteries the problem appears to be more pronounced and the problem may be the charger. On 10/26/2009 a representative of the manufacturer offered to send a replacement charger to see if the charger is causing the problem. I will upgrade this review, if that turns out to be the case.
Final comment: ( 1/13/2013 )
AccuEveloution sent us a reaplacement battery charger, but the results were about the same. Some batteries would not charge. I finally decided to try the more expensive An-Mann Energy 8 battery (a German company) charger and what a difference. It was able to successfully charge all of the batteries that failed on the AccuManager20 charger, with the exception of one. I have been using the Energy 8 charger with batteries of four different manufactures with no problems. I would highly recommend that you spend the extra money on the Energy 8, if you can. I have only had two additional AccuEveloution batteries fail over the last two years and that's out of over 80 batteries, but so far non of the other brands I have tried have failed to charge. Other brands of batteries that I have had success with are Tenergy and Sanyo (eneloop). The enloop AAs have been the best batteries I have tried so far.
on August 23, 2009
As accurately pointed out by another reviewer, this battery is NOT oversized. The AccuEvolution D is almost exactly 59.6 mm. The ANSI spec for a 'D' battery is 60.5 mm +/- 1.0 mm. Obviously, the AccuEvolution D is well within spec. Claims otherwise are not based on fact.
If your interest is performance and practical value,there is probably no better choice than the AccuEvolution 'D'. This battery has been in wide use for several years (initially as AccuLoop)and has earned an excellent reputation with many users. In numerous tests, it delivers an honest storage capacity of 10,000 mAh, which is considerably more than other brands of high capacity, low self discharge 'Ds'. The self discharge rate of the AccuEvolution is less than 2% per month at room temperature (even less at cooler temperatures), so you may expect this battery to stay charged longer when in heavy use AND when idle than LSDs with less capacity.
PUTTING THINGS INTO PERSPECTIVE: Based on the 'oversize' comment posted here in 2008 that has received so much attention, I tested the AccuEvolution for fit in a wide variety of devices (some spring loaded/some not)- and encountered zero problems. Even in my 4-stack flashlight (where size issues really matter) they fit fine.
Although variation in battery size should not be ignored, this is NON ISSUE regarding the AccuEvolution, and a minor one compared to 'off-size' battery compartments and compartments without springs. Springs solve the vast majority of 'fit' problems, but a battery compartment WITHOUT springs will not adjust to variations in battery size OR an off-size compartment. However, ALL such concerns may easily be assuaged simply by asking the seller (before buying) if the batteries OR device may be returned if they don't fit.
on May 25, 2009
mallory alkaline d cell lengths measured by me thru a plastic sandwich baggie for an thin insulator:
insulator on both ends: 2.374" = 60.3 mm
insulator on one end: 2.370 =60.2 mm
calculated true length:2.366: =60.1 mm
Looks like rechargeable lengths would be no problem.
I will test this by buying some of these, along with POWEREX MH-C808M charger and report back in a few weeks.
I own several vintage portable radios that run on D cells (Grundigs & Zenith Tranoceanics), and need to save money on cells.
UPDATE: MALLORY ALKALINE 2.382 =60.503 mm
AccuEvolution LSD D Cells 2.409 =61.189 mm
difference is 0.686 mm = .027" = less than 1/32"
Real life: a column of 3 D cells in my Zenith Transoceanic 1000D and Grundig Satlillit 210 radios fit just fine with either type of battery (common alkaline or Low Self Discharge AccuEvolution).
Reason the length of Mallory Alkalines are different in edited post from original is I re-zeroed my calipers to exact spec.
These rechargeables work really great!!
on April 16, 2011
A real D-cell, with 10,000ma-h, D-cell guts that works in my charger. There is a review that suggests these are slightly longer than, but I haven't had any trouble.
I don't have enough experience with these cells to know about their reliability, which is the sole reason I don't give them 5 stars.
on December 28, 2012
I would recommend that you watch your charging method. They may be damaged by bulk charging excessively. (like charging a whole group of 6 or 8 in a pack charger) I may have lost 2 sets prematurely with the too much use of this method, in an attempt to balance them. NIMH like to be charged individually. I am trying to recover one set, another set is probably too far gone, but I would say to only use the bulk charging when they are 1st new, and then not at all if possible. You can just sort them in the Powerex charger.--all the weakest ones to the far right followed by stronger ones to the left, and the strongest one to the leftmost slot. A battery tester is a lifesaver. One of the sets I lost never got off to a good start, as the two were weaker than the other four, and one of the cells bulged with the bulk charging method. The pack charger waits for a larger V-drop before shutting off, so I just wanted to give you a heads up. If getting a large set where the voltages have to match critically close, I would recommend getting a few extras, especially for the C size. It is a shame the company stopped making them, so the quality might not be the same. As for the Nuon D size, I can give you an idea why they failed. NIMH is never supposed to be charged in parallel, so that crappy design would explain the easy failure of your Nuon cells.(2 AA side by side in a size D can is just a design asking for trouble) It is a regret that this brand is disappearing, but it looks like the only LSD type that are closely matched is possibly Annsman. The Centura C typically don't stay matched, so you are stuck with the premium high self discharge, or the Nickel Cadmium, good enough for a low discharge speaker if matched, but not a CD boombox. I tried the Imedions, but they don't seem to match them as closely, luckily I have 2 sets of 6 C size -1 set of Tenergy Nicad and one set ofthese Accupowers I managed to cobble together. Get these Accupower Evolutions while you can!!! PS, if using Tenergy premium, don't use the pack charger 1st when new, use the Maha Powerex C808M when new. They come in different states of charge, and the 1st charge typically gets the D cells hot then shutting off with temperature delta T with two battery bars instead of the usual 3 bars when approaching full charge on the Maha. After that, run slightly down for several minutes, then use Maha charger again, then battery holder with pack charger ONCE, then let them equalize for several hours after the green light. If you try to put the premiums in that pack charger 1st, you will not get the green light. I have gotton the critical 120-130 degrees when I decided it was time to pull them, you wont get the green light if you just stick them 1st in pack charger, and it wont get them all full if one cell is almost empty out of the box. Pack charger will not terminate if the cells are in a different state of charge. Also, you may have one come almost dead in the set. You must use Maha Powerex 1st with that brand. Accuevolution need care for the 1st charge, but they do best if the pack charger is never used again with them. You don't have to approach the Evolutions with the same caution, but use the same care for all brands. (avoid Powerizer, Powerex, and Expocell and CTA battery brand as well as blue color Tenergy and Nicads with them))For that pack charger, go to Batteryspace.com, but you still need the Maha charger. Only use the 1.8 amp setting in the pack charger for the high capacity D cells, like the 10000mah, but not the C cells. The pack charger should not be used for AA,AAA as the current would be too much for them.
on January 2, 2011
My Wife uses an elliptical trainer that we bought years ago and the controls [including the motors to the clutch and a fan to cool yourself] run from four D cells. Alkaline batteries would last a month or so without much use of the fan. I put these batteries in the elliptical and they last more than 6 months easy. I know these work great and are cheaper than the Maha Immedion LSD equivalent [I am not a fan of their latest AA 2400mAh batteries ... none of them seem to actually have a 2400mAh capacity and their D batteries were released with their latest AA incarnation]. Stick to the AccuEvolution batteries and you will be very happy with your choice. At about $10 per battery, they are expensive, but they pay for themselves in four to six charge cycles.
on May 17, 2008
Be aware that the AccuPower D cells are not precisely the same size as standard D batteries; rather they are a bit longer. Four of these batteries placed end-to-end are about 1/8 inch longer than 4 standard, say, Energizer Alkaline D batteries placed end-to-end. That is only about 1/32 of an inch extra length per battery, but it was enough extra that I was unable to insert these AccuPower batteries into an O2 Cool battery powered fan calling for D batteries which I bought from Walmart as part of my emergency hurricane kit. Ordinary Energizer Alkaline D batteries fit fine. This was quite disappointing, especially when you consider the cost of the AccuPower cells. Other electrical appliances may not be so exacting regarding inserting the D batteries, and these batteries might work fine there, but it is startling that anyone would produce a D battery that is not the standard size. I have posted a photo which you can view; see the thumbnail photo link under the product photo.