Solar Light BatteriesSolar light batteries are a part of every outdoor solar light. When the solar cell creates electricity from the sun during the day, the energy must be stored somewhere. The battery is the perfect place to hold the energy until dusk, when the light needs the energy to shine.
The solar cell is wired to the battery with a diode, which keeps the energy flowing one way. A small photoresistor tells the battery when to begin releasing energy as the sun goes down.
Depending on the size of the solar light, you may have a single NiMH AA battery or several. The more LED lights that are attached, the more battery power you'll need to keep the light shining all night long. Even if you have several batteries, solar powered lights generally are not as bright as electric lights or low voltage landscape lighting.
Each LED light provides about half a candle's worth of light. While that isn't enough to provide strong illumination, it is enough to mark a trail or steps for safety.
NiMH or NiCad Batteries ?NiMH Batteries are usually chosen over the standard NiCad (nickel-cadmium) batteries because they last longer through the constant charge and release cycles.
Some people who use solar lighting have experienced brighter lights when using the NiMH batteries. They claim they also keep their charge longer.
The NiMH batteries also can be disposed of without harming the environment.
Batteries are the second most costly component in your average solar light. Some of the outdoor solar lights use AA sized NiCads and if they are charging well, they may last 1 to 2 years.
Some of the NiMH batteries can last up to 4 years. You may need to replace the NiCads more frequently than the NiMH batteries.
As long as the batteries are rechargeable and the same size, some people insist that there should be no problem switching out your cheaper NiCad batteries for NiMH batteries.
Other sources say you must stick with the same type of batteries that came with your solar light because of differences in charging.
The NiMH batteries may not do so well on a trickle charge rate like the NiCad batteries. If this happens, you can ruin your batteries. If you like the brighter light you get with the NiMHs, you may want to recharge the batteries yourself with a battery charger .
The charging current requirements may be very different between different types of batteries. Whichever type you choose, do minor maintenance from time to time to check for corrosion and faulty connections.
Top Consumer Rated Rechargeable Batteries
Sanyo Eneloop 8 Pack AA NiMH Pre-Charged Rechargeable Batteries
Sony 2500 mAh AA Rechargeable Nimh Batteries, 4-pack
It May Not Be Your Solar BatteryAn important thing to remember when dealing with solar light batteries is that the length of time listed on the package is an estimate, and may change due to geographic location, the seasons, the weather conditions, where you install the light and more.
Solar lights will not give you the same amount of light as standard outdoor lighting. Solar lights are more suitable for decorative purposes and accent lighting.
You may feel that the light is not functioning properly, when the real culprit may be overcast weather, or the solar panel may have gotten covered by snow or fallen leaves, preventing the battery from charging adequately. Your light may spend half the day in shade. All of these result in shorter illumination times and inadequate charging of the solar light battery.
When you need to change your batteries, be sure and check the connections. If you see any rust or corrosion, clean it off before adding new batteries. This regular maintenance check may help your solar light battery last longer.