Customer Reviews

Moonrays 97125 Rechargeable NiCd AA Batteries for Solar Powered Units, 4 Pack

5 star:		(24)
4 star:		(5)
3 star:		(9)
2 star:		(10)
1 star:		(12)

 

 

*EDIT 12/7/2011* They currently have an 8-pack of these batteries for a few dollars cheaper - Moonrays Rechargeable NiCd AA Batteries for Solar Powered Units, 8-Pack

*original review*
When I purchased my CCI Moonrays 95669 Solar Powered Metal Path Light, 6-Pack, Copper I decided from 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."

Wow I'm a nerd. But it makes me happy

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.

I just bought these batteries to change out in older solar lights where the batteries just seemed to die out. I could notice right away how much brighter they were than my old batteries. They light up my whole path outside, very nice. They even worked right away and I put them in at night, they did not need to charge up first. I really love this product, I bought 3 packs of them!

The batteries themselves are probably fine. The problem is that the ones I received had already expired and didn't work. Amazon replaced them for free, but those, too, had already expired. The end result for me was a lot of hassle and I still don't have any usable solar batteries.

They should last for up to a year and the ones that I have used as replacemnts, 4 out of 12 have only lasted 2 weeks. Batteries should last far longer, so rather disapointed in them.

The batteries had an expiration date that was already one year old!You could not see it before opening the package!Return!

The Moonray 97125 AA solar batteries quit within a month in my landscape lights. The lights were in full sun all morning, full daylight until evening during July in MO. Other brands have lasted several years in these lights with less light and sunlight.

Got these batteries for a wind chime with a glass ball that changes colors at night. Installed them and then it was cloudy/rainy for a few days so no light. After a few days of direct sun still no light. Very disappointing.

I found that although the batteries lit my solar lights brightly at first, as the weeks go by,they lose their power. We have had bright sunny days so I know that that is not the problem. I also let them charge in the lamp with it switched off for a few sunny days. Disappointing :(