Features:

• Universal charger recharges AA, AAA, C, D, and 9-volt NiMH batteries
• Perfect for use in high battery usage households
• Capable of recharging batteries over 1000 times
• NiMH rechargeable batteries last longer than alkaline batteries
• Recharger can save thousands of dollars in alkaline battery costs

Editor Reviews:

Product Description:
Rayovac Battery charger is a universal charger that will charge any size NiMH battery. - Charge up to 8AA or AAA; 4C or D; or 1 9V batteries. - Capable of recharging up to 1000 times - Perfect for high household battery usage

Amazon.com Product Description:
The Rayovac PS3 Rechargeable Battery Universal Charger will charge any size NiMH battery. This device will recharge up to eight AA or AAA batteries; four C or D batteries; or even a single 9-Volt battery. The PS3 is perfect for high battery usage households, and it is capable of recharging batteries over 1000 times. If your family or business burns through piles of regular alkaline batteries, grab yourself a stack of NiMH rechargeables and the Rayovac PS3, and start saving money.

Why Rechargeables
Today's high-drain, electronic devices demand rechargeable NiMH batteries. NiMH batteries actually last longer than alkaline batteries in most high-tech devices and they can generally be recharged up to 500 times. This high-volume rechargeability results in cost-savings that can add up to thousands of dollars. Plus, with Rayovac NiMH batteries, there are no "memory" problems -- recharge your Rayovac batteries any time, even if they are only partially drained.

Usage Tips

• Always charge NiMH batteries before first use
• For maximum performance, charge batteries prior to using if stored for more than one month
• NiMH rechargeable batteries are available in AA, AAA, C, D, and 9-volt sizes
• NiMH batteries can be disposed of with regular trash -- NiMH is safe for the environment

Rating : - Bulky, heavy, but surprisingly smart and versatile
I already have at least half a dozen smart chargers in the house, including top-of-the-line models such as the La Crosse BC-900 and Maha C9000, but I still wanted this Rayovac Universal Battery Charger (PS3) for the following reasons:

1. It can accept C, D, and 9V batteries in additional to the standard AA and AAA cells.
2. It can handle rechargeable alkaline cells in addition to the standard NiMH or NiCd cells.
3. It has the potential to recharge up to 8 AA or AAA cells at once.

So far, I'm very satisfied with this charger. Of course it is bulky and heavy. But that's to be expected for an unit that can accept four D-cells at the same time. For home use the size and weight is not an issue at all.

I'm happy to report that this charger is a lot smarter than I previously imagined. Unlike a typical dumb charger in this price range (for example: the Energizer CHFCV Overnight Family Charger), the PS3 has four independent charging channels. That means I am free to charge different cell in any channel. Each channel comes with a status indicator LED, which goes out once the cell is fully charged. But most of all, this charger is smart enough to recognize the difference between NiMH cells and alkaline cell, and can pick the correct charging method accordingly.

When an unknown cell is inserted into the PS3, the charger first starts off with a trickle current (800mA peak current at 10% duty cycle, or an average current of 80mA). Based on the voltage profile of this cell, the PS3 can determine whether this is an alkaline cell, or a NiMH cell. After two minutes, the duty cycle is increased to 60%, so the average current is now around 480mA. For a NiMH cell, charging will continue until a negative dV/dt is detected, in which case it switches back to trickle current again. But for an alkaline cell, charging current will gradually decrease with higher terminal voltage until it reached 1.65V.

The Rayovac PS3 is designed to recharge the Rayovac 'Renewal' brand of rechargeable alkaline cells (which are now discontinued). The user manual warned against charging ordinary disposable alkaline cells, but I experimented with it anyway. So far, I have observed very good results with recharging Duracell alkaline AA cells [see warning below]. Of course, the capacity of a recharged alkaline cell is lower than that of a fresh cell, and it drops with each subsequent cycle. But since I can squeeze another half a dozen cycles out of an exhausted alkaline cell at no additional cost, I really should not complain.

Back to the charger itself, I do have a complaint about its claim of "recharge up to 8 AA or AAA batteries". It turns out that each of the four charging channels can accept one to two AA or AAA cells, but the two cells are electrically connected in parallel. So in case somebody accidentally placed two cells of different battery chemistries (NiCd, NiMH, or alkaline) in the same channel, the one with lower voltage will discharge the other one. The charger may also get confused and fail to terminate correctly in such case. It is safer and faster to charge only one AA or AAA cells in each channel.

[WARNINGS:]
1. Do NOT try to recharge alkaline cells that are completely exhausted (terminal voltage below 1V). It will not work.

2. Do NOT try to recharge Energizer alkaline cells. Four Energizer AA cells I tested completely dropped dead after just two discharge/charge cycles. Two D-cells started leaking electrolyte a few days after charging. Luckily they were left outside and not being used.