Customer Reviews

PowerGenix ZR-PGX1HRAA-4B 1 Hour Quick Charger with 4 AA 1.6v NiZn Rechargeable Batteries

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4 star:		(6)
3 star:		(6)
2 star:		(4)
1 star:		(21)

 

 

This product (PowerGenix 4-Position Charger with 4 AA High Voltage 1.6v 2500 mWh ZiNc Rechargeable Batteries) contains an 'one hour' charger specially designed for Nickel-Zinc AA/AAA cells. But it does not fully recharge to 100% within one hour. If you read the fine prints, it actually says "For maximum capacity from batteries charge up to 2.5 hours".

Despite its misleading name, this is actually a decent 'smart' charger. It works from universal input voltage (100-240V), and accepts 1-4 AA cells or 1-2 AAA cells. Each cell is charged individually (not in pairs). The red LED lights up during charging, and the green LED lights up when done. Just remember that you must not use this NiZn charger for NiMH cells, and vice versa.

The batteries are the new Nickel-Zinc rechargeable AA cells. The greatest selling feature of NiZn cell is its higher terminal voltage. The nominal operating voltage of NiZn is 1.65V, which is very close to alkaline and 30% higher than NiMH (1.25V nominal). However, when freshly charged, the NiZn terminal voltage is around 1.85V, which is dangerously high for most battery-operated appliances.

Upon closer examination, many of the alleged benefits of NiZn turn out to be just marketing hypes. For examples:

"Higher Energy Density":
Despite what the confusing rating on the package ("2500 milli-WATT-hour") may suggest, the PowerGenix AA cell does NOT contain more energy than a SANYO eneloop AA cell. This is because its current capacity is much lower at just 1500 milli-Ampere-hour (based on data sheet of PowerGenix AA cell, and verified by my own testing).
- Energy in eneloop AA cell: 1.25V * 2000mAh = 2500mWh
- Energy in PowerGenix AA cell: 1.65V * 1500mAh = 2475mWh

As an example: Suppose a set of 4 eneloop AA cells can power your external flash unit for 1500 shots, then a set of 4 PowerGenix AA cells will provide roughly the same number of shots. The difference is that your flash unit will recycle about 30% faster with the NiZn cells due to 30% higher battery voltage. On the other hand, this high rate of fire could cause the flash to over-heat and burn out.

"Long Cycle Life":
PowerGenix claims that NiZn has a service life that 'meets or beats' that of NiMH cells. But according to technical data found on PowerGenix web site, the NiZn cell is only rated for 200 cycles at 100% deep discharge. Most NiMH cells are rated for 500-1000 deep discharge cycles.

"Long Shelf Life":
PowerGenix claims the NiZn cells have longer shelf life than Lead-Acid batteries (which are notorious for high self-discharge rate), but did not compare against NiMH cells. In the "Charging Procedure" section, it says to recharge the NiZn battery every 30 days!


In summary: While the higher voltage offered by PowerGenix NiZn cells sounds attractive, it could damage or shorten the life span of your battery-operated appliances. In addition, NiZn cell does not pack more energy than eneloop NiMH cell, yet it suffers from lower cycle life and higher self-discharge rate.

On the other hand, suppose you have an inexpensive camera (*cough*Kodak*cough*) that does not work well with NiMH cells, then the higher voltage offered by NiZn cells may be exactly what you need. If your camera gets fried... oh well, at least you have an excuse to upgrade to a better camera!

[Update on Feb 9, 2010]
Several people have commented that my review above is heavy on technical data and not on personal usage experience. Please note that it was written shortly after NiZn AA cell was introduced. See my other review on PowerGenix ZRPGX-AA8 AA 8 Pack, which was written 3 months after this one. It includes my preliminary test results on self-discharge rate (good) and cell longevity (not so good).

Another point to note is that: since I'm an engineer, I'm overly concerned about applying 20% higher voltage (1.8V vs. 1.5V) to any electronic appliances. For example, I have tested my MAGLITE SP2209H 2-AA Cell Mini LED Flashlight over difference input voltage, and concluded that applying anything higher than 3.3V is dangerous (see my Customer Image for details). But other people may be happy to get extra light from higher voltage, without knowing that this can severely shorten the lifespan of the LED. Ignorance is bliss.

[Update on Nov 21, 2010]
My original review was written more than one year ago. At that time, I was just pointing out the marketing hypes surrounding the release of this product. Since then, I also found NiZn cells to be very poor in terms of quality and longevity.

My first set of four NiZn cells was used for capacity testing and long-term self-discharge testing. They have gone though maybe 20-30 deep discharge/recharge cycles (discharged down to 0.9V only, not 0V) over the past year. As of right now, two out of four cells have already failed, suffering from voltage depression and rapid self-discharge problems. The other two suffered from reduced capacity (~1200mAh, down from the original 1500mAh). The PowerGenix '1-hour' charger needs to detect 1.9V during charging, before it can change from constant-current mode to constant-voltage mode. When voltage-depression hits a cell, its voltage cannot reach 1.9V during charging, so the NiZn charger will simply fry the cell!

[Update Jan 31, 2011]
I recently discovered two other problems with the PowerGenix '1-hour' charger.

1. If a NiZn cell has been severely over-discharged and its voltage drops below 0.5V, the charger may not be able to detect its presence. If you insert this 'dead' cell together with three other good cells, the charger will not give you any warning signal (red LED flashing). But by the time the charger finished charging (green LED on), this dead cell is still empty. In this case, you need to use a 'dumb' NiMH charger to charge the dead cell for a few minutes, so that it can be recognized by the PowerGenix charger again.

2. If you store a set of fully charged batteries in this unplugged charger, each cell will be draining a current about 5.7mA into the charger. That means after about 10 days, all cells will be completely drained! With most other NiMH chargers I have tested, the leakage current is only 0.05-0.5mA, so you can store cells in them for several months without too much loss.

Interesting technology....and somewhat scary if you look at the 1.8 volt figure. I got a 2 set of them to test. I have UW LED lights..and two large strobes that both take 4 AA batteries.

Until trying these, I have been using eneloop's (or the japanese duracell version)..which are very nice nimh's. The larger capacity standard rechargables work well in the strobes for the first 20 or 30 cycles, but eventually one of them will have charging/discharge issues and mess up the strobe firing and recycle time.

As they are higher voltage, there is the possibility that they would not work, or could damage equipment, so I started my testing with a simple 4 AA LED light that produces around 100 lumins. I charged the batteries and put them in light, and tested the light for one hour every week. The light was slightly brighter initially, but to my amazement, did not loss very much brightness over a two month test window (standard Ninh's drop off considerably after the two houra with this light). After nine weeks and 9 hours, I stopped the test (the light is supposed to last 6 hours with standard Ninh's).

Note: Capacity and discharge rate are related with batteries....faster usually means less capacity, slower means more.

Only issue I had was that this underwater light was not meant to be run for any length of time on the surface and there was some heat distortion of the plastic case making getting the thing apart really tough. My latter tests were with lights in water.

Then I installed them in a larger LED with 180 lumin light output....to my surprise, the light was the same intensity as with Ninh's.. as it turns out the unit has a voltage regulation system and and over temperature sensor.. which never went off. However, overall light output was much more consistent over the 4 hours I tested it. ( the time the mfg stated the light would be at around 25% output).

Having success with these two guys, I tried them out in one of my strobes. Ok, the recycle time is faster... and I suppose, if my camera could recycle faster and I could shoot fast enough to over heat them. However, I would find that very difficult to do, as one has to focus and compose the shot, and that takes time.

Strobes and cameras tend to do short duration, rapid charging... which is very stressful to batteries. Each of my strobes have three flash heads, and they recycle in around 2 -3 seconds and have any battery variation in internal resistance or capacity and they will not charge correctly. It has been common to shoot 40 or 50 flash images, and then have to reset the auto system due to a faulty charge cycle...

Note: These are underwater strobes, and essentially every image is a strobe pictures...so far this year, that means around 5,000 strobe flashes.

Recyle time, after a couple hundred flashes, takes less than an hour, compared with the typical 4 hours for eneloops and the best battery chargers I can find.

No battery I have used has ever recharged as fast or been as cool after recharging. That, by itself, would make it 5 stars to me.

I have tested the voltage after using them in the strobes for a day and have only seen less than a .1 volt variation.

I think the charging time issue is nothing more than the difference between a typical charge and the time it takes to completely charge dead batteris.. which hopefully no one does.

I happen to have all the test equipment necessary to do detailed electrical analysis... but these are just batteries and in the end, they either work better or they don't....

Nice product...

I've been using these new nickel-zinc AA cells for about 2 months now. I'm impressed by how long they will power things compared to the usual NiMh cells.

I have a Magellan GPS unit that uses 2 AA's. It was probably designed for alkaline cells. New alkaline cells give a full scale battery bargraph, but freshly charged NiMh cells only make the bargraph hit about 80%. NiMh cells drop to about half scale after an hour. I only get about 4 hours with NiMh cells before the voltage drops too low and it turns itself off. Alkalines will last about 7 hours. The new PowerGenix NiZn cells give a full scale battery bargraph for about 3-1/2 hours, then it slowly drops until the unit turns off. My first test powered the GPS for 6 hours and 20 minutes, the second time it went 6 hours and 55 minutes. I left the batteries in the charger longer the second time I charged them, about 4 hours instead of 2. With my GPS, the PowerGenix AA's lasted almost twice as long as 2200mAh NiMh.

I have also used these in my Fuji digital camera that uses 2 AA's. They also last a long time, longer than the NiMh cells I have used in the past. The LCD display is also just a little brighter with the NiZn cells.

I have a little Grundig G6 radio that also uses 2 AA's. It won't turn on with these installed. I'm guessing that the radio is sensing the higher than usual voltage (about 3.6 volts) and won't power up. This is the only device I have found so far that isn't happy with the NiZn cells.

When these come out of the charger, they read about 1.82 volts without a load using my Fluke DMM. Of course the voltage will drop when current is drawn and as the battery discharges.

To sum it up, these cells act a lot more like alkaline cells with the higher voltage available. It takes a lot longer for the voltage to drop down to about 1.2 volts per cell when comparing to NiMh types. These start off at a higher voltage than alkaline and take a good long time to drop to the point when you need to recharge.

Give these a try, I think you'll be happy. I'll be buying more AA's and some of the AAA size when they are available.

I have the charger and 16 batteries purchased from Wolf Camera about a year ago. During camping, I ran the batteries in my 4W florescent light and recharged them when it dimmed about 5 times. Some of them refused to charge because the charger gave a blinking red light. I was able to get the charger to accept those by charging them on an Ice battery analyzer for about 100 mAH at 200mA or up to 1.9V cutoff and putting them back in the charger. They would accept a charge, but the capacity was less than 1Ah. I did discharge test on all 16 of them at 1 amp down to 1.2 V and wrote the capacity on them one year later. The best one did 1033 mAH, the rest were 500-800 mAH. Many have died. 3 had internal shorts that would drain them to 0V in a day. 2 more died too quickly to be used with the others. 1 began to leak from the top in the charger the first time I recharged it. About half a dozen are rejected by the charger. The problem with them is that you have to drain them about 1/3 of the way and charge them right away or they die. This is impractical in reality because they have a high voltage. By the time your camera, light, GPS, or whatever act like the batteries are weak, you have drained them too much for the charger to charge them again. Stay away! I wouldn't expect them to last more than 1 year or 6 charge cycles. Unless your device won't work with NiMH or alkaline batteries I would not bother because at $2.50 each and with flaky reliability it is hard to get your money's worth.

I got these batteries as an alternative to Sanyo Eneloops in an external camera flash. Overall I found them to work pretty well, the flash would recharge somewhat quicker than with the Eneloops.

I also did some cursory testing on an autodischarger and found the batteries could hold up under 10 Amp Discharge, the limit of the autodischarger, which is rare for consumer cells. Using the same autodischarger I found Eneloops hold up only to about a 6 Amp Discharge. So they are better at least "on paper".

On the downside it's hard to tell how these batteries will function in a given device without trying it. In theory they may improve the operation of that device, they may not, and they may even damage the device due to overvoltage or overheating. The only way to find it is to try it yourself (or find someone else who has tried it and given a report).

Basically if you have a device like a camera flash that takes a while to recharge while in use, and you want it to do recharge faster, you might want to try these batteries. Just know they might help or they might not, no guarantees, it depends on the actual design of that device.

So, I saw a wonderful write up in a PC magazine about these, and I thought, gee, I'll give them a try as my little cannon camera chews up batteries and spits them out. I'm talking 25 flash photos and they are done, NOT very fun!!

The day I received these I plugged them in to recharge and read the instructions. It CLEARLY states that the quick charge will get them to about 80% and another 3-4 hours will get them to 100%, so I let them charge overnight. The next evening, while watching a movie, I placed a set in the camera and started firing off photos as fast as I could. The refresh rate on a short range flash was VERY quick, almost instant. On a long range flash, the recycle time would lag, depending on a variety of circumstances. (Did I let the batteries rest, how "fresh" were the batteries, etc.)

At the end of it all, and after my wife gave me enough looks like I was crazy, I fired off 250+ photos WITH a flash! (They were still alive, I just got tired of taking test photos!) That is 10 times the going rate of the alkaline batteries that it typically chewed thought. Even lithium batteries don't seem to hold up that long.

At the end of the day, I am VERY happy with this purchase. The test camera was a Cannon PowerShot A720 which only take two batteries at a time.

You won't regret your purchase for life draining gadgets!

At last some re-chargeables that give the same or slightly more (1.6) volts as ordinary AA cells. Getting much better utilisation in the camera but early days to assess longevity. Cant be worse than some of the over-hyped Ni-Cd and Ni-Mh cells. These batteries need more exposure so lots more people find out about them.

Alkaline batteries are wasteful and just don't last long. NIMH and NICD don't have the needed voltage to run some of my devices, like my Olympus FE110 camera. Alkaline batteries go for about 50 pitures, CRV3 Lithium Ion don't fit in the camera battery compartment, and Fully charged NIMH, even eneloops show up in the camera as weak and only allow a couple of pictures before turning off. My alternative has been to buy the expensive non-rechargeable Lithiums. Functionally this works great but it is expensive and wasteful of resource.

The new Power Genics AA ZiNc batteries work great in every application I have tried them in. I've not had them long enough to know if they suffer from the discharge problem that NIMHs do, but I've had no problems of the slightly higher voltage causing any issues with my equipment. It's awesome to finally have a solution for our battery hungry FE110 camera. I can't wait for AAA's to come out!

These (Ni-Zn) cells might be considered as a rechargeable substitute for typical alkaline AA or AAA cells, which typically deliver from 1.59 to ~1.3 volts though their useful discharge range. The Ni-Zn rechargeable cells (typically 1.8 to 1.5 volts) offer an advantage over the previous (Ni-Cd or Ni-MH) rechargeable substitute cell technologies which only deliver roughly 1.4 to 1.2 volts through their useful discharge range. In many cases, portable electronic items will indicate low battery voltage and then quit even though these cells may only be partially discharged. This is due to the lower operating voltage of Ni-MH cells compared to the alkaline cells normally used with portable electronics. The new Ni-Zn rechargeable cells simply don't have this problem because of their higher operating voltage.

However, I have seen some instances where portable electronic items "complained" about the higher (>1.6 volts) initial voltage of Ni-Zn cells, and they essentially could not be used in these cases.

BUT, I've found a solution for this problem. In this situation, one can often use a half and half mix of Ni-Zn and Ni-MH cells provided that they are well matched in terms of their charge capacity (mAh) rating. Note, if the cell is rated for its energy capacity (mWh), you can calculate the mAh rating by dividing the mWh rating by the operating voltage. I have found that this works very well. BUT, the user must make certain that discharged cells are ONLY recharged in the chargers designed for the specific cell types.

And one more important detail: Be absolutely sure that the chargers being used can charge ANY number of cells (e.g., from 1 to 4). Chargers that charge cells in pairs run a huge risk of shortening the life of cells, due to overcharging the cell that happened to be discharged less than its mate in the charger. While the PowerGenix charger I purchased can charge any number of AA cells from 1-4, I've noticed than a high percentage of the Ni-MH charges on the market today can not do this.

If you want a better charger or battery than the PowerGenix NiZn (1.6 V-2500 mWh), you WILL NOT find it.
My Samsung SL30 digital camera goes through regular AA's and even rechargeable NimH's like they're for free. But it goes for days on these. They last a long time and charge very fast. Put simply, hands down it's one of the best products I've ever purchased.