Customer Reviews

Rayovac 4.0 Rechargeable AA 4-Count (Pack of 2)

5 star:		(11)
4 star:		(12)
3 star:		(2)
2 star:		(0)
1 star:		(1)

 

 

The product description of Rayovac 4.0 AA cells appears to be intentionally deceptive. It says "Rechargeable Battery with Lithium Technology", but did not mention anything about the battery chemistry, voltage, and capacity. On the front of the package it says "Compare to ADVANCED LITHIUM", and "Ready to use like LITHIUM". All these seem to give the impression that "Rayovac 4.0" is similar to the Energizer L91BP Lithium AA Battery, which has a higher operating voltage (1.6V) and larger capacity (3000mAh) compared to normal NiMH AA cells.

Upon closer examination, however, you'll see the fine print of "NiMH 1.2V" on each cell. Suspiciously, its capacity (mAh) is still not specified. So despite of all the hype, this is still a Nickel-Metal Hydride battery, perhaps with a trace amount of Lithium added to justify the claim of "Lithium Technology".

I tested four Rayovac 4.0 AA cells using my La Crosse BC-900. Right out of the package, they hold an average charge of 1485mAh, or about 70% of full capacity. After two more charge/discharge cycles, their avarege capacity improved to 2080mAh. This performance is nearly identical to that of Rayovac Hybrid AA Batteries, which I have tested many times before. Further examination also revealed that the (+) and (-) terminals of "Rayovac 4.0" are exactly the same shape as "Rayovac Hybrid". Therefore I'm convinced that those two series are in fact the same cell under different wrappers.

I really dislike the shiny wrapper of "Rayovac 4.0" cell. It makes the cell look too much like the Energizer Lithium AA cell, and it doesn't even mention "Rechargeable" on the wrapper. I can only imagine how many of those rechargeable cells were thrown out after first use, because people confused them with desposable cells.

On the other hand, the price for 8 of those "Rayovac 4.0" AA cells is less than half that of Sanyo Eneloop 8 Pack AA (as of this writing). This makes them an amazing value. It is much better to buy those, instead of trying your luck with other so-called "Ready-to-Use" rechargeable batteries from less reputable brands.

[Update on Feb 25, 2010]
Data on long-term self-discharge rate: I have tested four each of Rayovac 4.0 AA and AAA cells, after 100 days of storage at approximately 19 degree C. The average charge retained in both sets were exactly 86% of original. This is consistent with the self-discharge characteristics of Sanyo eneloop and Rayovac Hybrid.

Just got off the phone with rayovac. The girl said these are Nimh and 2300 MaH

Here's a copy paste of the spec sheet I got from them, there were some charts in there, they obviously did not copy over. Hope this helps all you techno-dweebs.
Enjoy!
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Rayovac Stock Number: LD715 Name: LD715 AA Nickel Metal Hydride, R2U Grade (2300)

Cell Type: Nickel Metal Hydride Size: LD715
Size Designation ANSI C18.2 1.2H2
IEC 61951-2 HR 06
Physical Attributes Weight 28 g
Size 14.2 (D) x 50 (H) mm
Volume 7.89 cc
External Insulating Cell Jacket Polyvinylchloride (PVC)
Nominal Voltage 1.2 V
Discharge Capacity* Typical 2300 mAh
Minimum 2139 mAh
DSC Test Number of Shots 400Minimum
Energy Content Energy Density 350 Wh/l
Specific Energy 99 Wh/kg
Charging Regime Standard 230 mA (0.1ltA) x16 hrs
Rapid 2300 mA (1ltA) to -dv = 8 mv
Maintenance 69-115 mA (0.05-0.03ltA)
Charge Temp. Range Standard 0° to 45°C
Rapid 0° to 45°C
Discharge Temp. Range -10° to 45°C
Storage Temp. Range < 3 months -20° to 50°C
3 - 9 months -20° to 40°C
Cycle Life Expectancy Up to 500 cycles
Meets EPA requirements for landfill, no mercury added formulation
*After standard charge at 20°C followed by discharge at 0.2 lt to 1.0V

just received the batteries a few days ago. Popped the first four into my lacrosse charger to test capacity. All four were between 1970 and 2080 mAh. Will see what they are after a few charge discharge cycles.

I would have given 5 stars except for the battery labeling...nowhere does it say rechargeable, so like another rater, I assume a lot of these will end up in the trash, which is a shame.

Other than that, a great value at $1/battery

These seem great and at about $1 battery, who needs alkalines anymore?! (except where you need 1.5 volts or else!) If it says 4-pack, pack of 2 that means you get 8 batteries!

One point: As noted, the packaging is weirdly deceptive, but also be aware that the battery doesn't mention the amperage rating (2300 for AA I believe) and most glaringly doesn't say RECHARGEABLE (!) I wrote in permanent marker "Rechargeable" on each cell, since if you live with other humans, it's likely they will toss the batteries out when they seem 'dead'. Just an FYI.

Rayovac Hybrids are excellent at retaining a charge, and delivering plenty of power when needed.

I have them in toys, wall clocks, flashlights, camera etc. I purchased this '4.0' model as well, knowing that the cells are the same as the Hybrids.

Update:
One and a half years after, these batteries have performed worse than my other set of batteries. I have been doing discharge-test function on my LaCrosse BC-700 and they are now registering under 1,000mAh.

Original review:
I have tried a lot of pre-charged batteries like Eneloops, Duracell, Rayovac Hybrids, & Yuasa Enitime. Compared with Rayovac's Hybrids, the Rayovac 4.0 is very similar in almost every aspects.

I wanted to know how much mAhs it will pack after a discharge; each AA battery averages around 1475 mAhs on discharge. So, that's how much it has out of the box. Charging them, I got an average of 2050mAh. Not bad, not far with the rest of the guys.

The way they are marketing these batteries is a mystery. The package says ready-to-use and rechargeable, but you will not know that unless you look closer where it is written smaller on the side like a fineprint. After you throw away the package, it is even harder to tell on the battery itself as the only indicator that they are rechargeables is the word NiMH. It does not say anywhere rechargeable at all. Not even mAh rating is printed anywhere. Batteries are made in China.

Definitely rechargeable metal hydride batteries. Tested to about 2000 mAh out of the box. For the price they are working great.

I bought these batteries because they were on sale for a fabulous price. After having used them for a year I think these batteries offer great value and are a quality product.

I like having lots of NiMh batteries and have invested in a top end Maha 8 cell charger and ZTS tester. I have enough different batteries to have experienced good and bad ones.

Two key measurables in batteries are how long they last under load and how long they remain charged before you use them. In the latter category these batteries shine. Most of my other NiMh rechargeable batteries won't last more than a month or two before losing more than half their charge. After 4 months the Rayovacs were still at 80% charge versus 40% charge for the next closest battery.

I haven't done any objective testing to see how long these batteries last under load. In my battery hungry Canon Powershot camera they seem to last as long as any other in the same 2300 mAh range.

I believe Rayovac may have discontinued these batteries in favour of their Hybrid line. I paid $1 per battery including shipping. If you get these at close to or below $1 per battery then buy all you can.

The package came loose in the box but work fine. I took them right out of the box, without charging, and put in my camera for a ski trip. After two days, the low battery indicator on my camera appeared while I was shooting outdoor at -20 degree Celsius. However, the error went away when the camera was brought back to room temperature. It lasted for a whole week with tons of pictures and videos. I think it even lasts longer the eneloope batteries that I have. I'm very happy with the purchase.

I bought these for their low internal resistance. When the daughters' handhelds go dead, I like to be able to pick up a fresh set and immediately get them back to their game. The old batteries I was using didn't like to hold a charge while not being used, and wouldn't last long enough to even charge another set. These work much better.

I have to admit that the Sanyo EneloopsSanyo NEW 1500 eneloop 8 Pack AA Ni-MH Pre-Charged Rechargeable Batteries are even better, but being more expensive, I tend to save them and use the Rayovac's whenever possible. The Eneloops spend a lot of time in the Wii controllers.