Bests & Worsts Reviews from Amazon

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 It is sad to see that the U.S. is now being used as the largest dumping ground (literally) for those outdated products.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"!