should i buy Moonrays 97125 Rechargeable NiCd AA Batteries reviews

Enjoy an uninterrupted glow from solar-powered motion lights, lawn ornaments, pathway lamps, and other fixtures with help from Moonrays' 97125 set of four rechargeable 600 mAh NiCd AA batteries. Because the batteries harness their power from the sun, they provide a long-lasting, exceptionally efficient source of energy--one that reduces costs and eliminates both the hassles and hazards of electric cords and cumbersome wiring. Furthermore, the compact batteries store easily in a drawer for use as needed, and they can be used to power many of Moonrays' beautiful lawn, garden, and home lighting fixtures (sold separately).
With more than 75 years of experience by parent companies in the wire and cable products field, Moonrays' extensive line of outdoor lighting carries a fine tradition of excellence, skill, and know-how. The company's solar-powered products require no wiring or electricity, making them energy-efficient and cost-saving alternatives to traditional lighting sources. From enchanting and whimsical garden accents to attractive landscape and home lighting options, Moonrays strives to provide their customers with visually pleasing and socially responsible ways to customize, secure, and invest in their outdoor spaces. Furthermore, they combine a modern aesthetic with advanced technology to beautify and simplify the lighting of residences, cabins, outbuildings, and vacation homes.the beginning to switch out batteries in half of the lamps with the other battery types because I had read the other review for this battery pack.

Honestly, I found these work better through the night over a longer period of time. Sometimes I wake up very early in the morning for work, and have noticed that the lamps with these batteries have lasted longer and brighter into the morning. It has been a couple months since i got the lamps and will definitely purchase these batteries again.

I decided to do a little research on Wikipedia to find the reason.

These Moonrays batteries are Nicd, on the page it says "The primary trade-off with NiCd batteries is their higher cost"
But the advantage it says is

"the NiCd battery has a lower self-discharge rate (for example, 10% per month for a NiCd, versus 30% per month for a traditional NiMH under identical conditions"

that means that over time, these batteries will hold their charge longer than others.

The other type of rechargeable batteries are the NiMH batteries, and their page also says
"NiMH cells historically had a somewhat higher self-discharge rate (equivalent to internal leakage) than NiCd cells. This is not a problem in the short term, but makes them unsuitable for many light-duty uses where the battery would normally be expected to last many months or years."NLee the Engineer: I'm an ELECTRICAL Engineer. You missed the most important consideration: NiMH batteries should only be recharged in a highly controlled environment such as in your iPod, digital camera with a NiMH charger, NOT DIRECTLY BY A SOLAR PANEL ! Solar panels should either have their own charge controller or use batteries that withstand routine overcharging. NiMH BATTERIES WILL *EASILY* BE DESTROYED BY OVERCHARGING. NiCd batteries fair somewhat better.

ALL RECHARGEABLE BATTERIES SHOULD BE RECHARGED WITH A RECHARGER whether it's powered by a solar panel or from an AC wall jack.

There is simply no reason why anyone should buy those NiCd (Nickel Cadmium) rechargeable cells for solar rechargeable light applications. For about the same price, you can easily find NiMH (Nickel Metal Hydride) cells which offer the following advantages:

- Higher capacity: NiMH AA cells are typically 2000-2700mAh, compared of just 600mAh for those NiCd cells.
- No memory effect: NiMH cells are less likely to suffer from reduced capacity when they are partially charged and discharged.
- Environmentally Friendly: NiMH cells do not contain Cadmium, a highly toxic heavy metal. Expired NiCd cells must be disposed in special battery recycle bins, but most people don't bother to do that. So those cells end up buried in landfill or, worse yet, incinerated. (*)

The only advantage NiCd cell has over NiMH is lower internal resistance, which allows it to provide very high peak current in short bursts. That's why NiCd cells are still used in cordless power tools and RC race cars. But in the case of solar rechargeable lights, the battery current is delievered slowly over 8-12 hours. So NiMH cells, with much higher capacity, are far superior as replacement batteries.

(*)UPDATE:
As of Sep 2008, imports of NiCd rechargeable batteries were banned for all EU countries (thanks to a 2006 Battery Directive). Prices of NiCd cells plummeted as a result. It is sad to see that the U.S. is now being used as the largest dumping ground (literally) for those outdated products.

[Update#2 on Nov 29, 2010]
Some people claim that NiMH cell cannot be used in Solar charger because it needs higher voltage to recharge. This is COMPLETELY FALSE based on my own measured data, shown in the Customer Images section. Note that both NiCd and NiMH cells have nearly identical voltage profiles (adjusted for time scale) during slow-charging.

[Update#3 on May 17, 2012]
It should be noted that the same company is now selling Moonrays 97143 AA NiMh Pre-charged 1500mAh Rechargeable Batteries for Solar Lights. So there goes the claim that "you can only use NiCd for solar lights"!