Energizer CHP4W8-4 Smart Recharge AA/AAA Charger with 8AA and 4AAA NiMH Batteries

Energizer CHP4W8-4 Smart Recharge AA/AAA Charger with 8AA and 4AAA NiMH Batteries..

Buy Energizer CHP4W8-4 Smart Recharge AA/AAA Charger with 8AA and 4AAA NiMH Batteries By Energizer

Most helpful customer reviews

721 of 745 people found the following review helpful.
'Smart', as in 'Maxwell Smart'?
By NLee the Engineer
This package (Energizer Smart Rechargeable Charger for AA/AAA Batteries, with 4 AA Batteries Included) contains a very impressive-looking charger. The charger (CHP41US) features a countdown timer, a battery 'Fuel Gauge', and four bad-battery indicators. It looks like a very smart charger - until I examined closer.

The first warning sign is that: Would You Believe this charger can only charge in pairs? That is, it cannot handle 1 or 3 cells. A real smart charger has to monitor and charge cells individually, because this is the only way to ensure that each cell is not over-charged or under-charged.

The next thing I found out is that: the so-called 'countdown timer' is mostly for show. It's The Old "2-bit counter in a 7-segment display" Trick. The display always start from '8' (eight hours) when a pair of depleted cells is inserted, regardless of the actual remaining charge time. As the batteries are being charged up, the counter simply decrements through '6', '4', '2' and finally '0', even though the actual charge time may turn out to be just five hours.

The 'Fuel Gauge' on this charger is marginally useful. It shows 1-4 bars, based on the combined voltage of one battery pair. If two pairs of batteries were inserted, the fuel gauge is for the pair with the lower voltage. It soon dawned upon me that both 'countdown timer' and 'fuel gauge' are based on the same information. For examples:
2.2V = 1 bar = 8 hours,
2.4V = 2 bars = 6 hours, and so on.
By the time the combined voltage of two cells reaches 3.0V approximately, the charging is terminated. If the two cells have different capacities, then the lesser one is inevitably over-charged.

One problem with this single 'fuel gauge' is that: it does not tell you which cell is at what status. In comparison, other chargers in this price range may contain four individual status indicators. For examples: Targus Digital TG-LCD2700 Charger with LCD Display and Sony BCG-34HRMF4 Battery Charger with LCD Display.

The same problem applies to the four bad-battery indicators. If you insert one good cell with a bad one to the left two slots, for example, both indicators light up in red. But you still can't tell which cell is bad.

The four rechargeable AA cells included in this package are the "New" Energizer 2300mAh NiMH batteries. Note that their capacity is lower than that of previous generation (2500mAh), but they are not advertised as 'Pre Charged' or 'Low Self Discharge'. My own testing, using the La Crosse BC-900 charger/analyzer, indicated that those are indeed traditional NiMH cells. That makes me suspect that Energizer simply rolled back its rechargeable battery technology to circa 2004, instead of moving forward like other battery companies.

To be positive, I should thank Energizer for NOT making yet another timer-based dumb charger, or another '15-minute' battery roaster. But in calling the CHP41US a 'Smart' charger, Mr. Energizer Bunny just Missed It By THAT Much!

[Update on Nov 10, 2012]
Energizer now bundle this charger with four lower-capacity rechargeable AA batteries. The new light-green batteries have a capacity of just 1400mAh. That makes this package an even worse value than before.

82 of 88 people found the following review helpful.
"Indicator" says all batteries are bad, even new ones.
By greyhoundude
I had the same problem as a previous reviewer. This charger indicates all batteries are bad, including the batteries that came with it. I bought it new and locally for $9.99, which is what the batteries alone would have cost me, so it wasn't worth returing. Hopefully it actually charges the batteries and it's just a screwed up indicator. Still, it should do what it's ADVERTISED to do.

83 of 96 people found the following review helpful.
Xcellent for Xbox 360 controller
By 1Dub79
I was skeptical of buying rechargeable batteries because some are duds. However, I bought my oldest boy an Xbox 360 and I did not want to continuously pay money for batteries. Therefore, I decided to buy this charger. It works great. The game is played a ton. Still, the batteries last about three weeks, prior to needing re-charging. Initially, you will have to charge the batteries for eight hours for a full charge. The countdown timer indicates how much time is left for a full charge. Once the counter reaches 0, the batteries are fully charged. Since the charging duration is long, I would suggest keeping two batteries charged, at all times. Therefore, when the other two batteries run out, they can be switched with two charged batteries. I don't know what the issue is with other reviewers of this product. All I can say is I got my money's worth. Not to mention, I am saving money by not continuously paying money for batteries. That can be very expensive.

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