Anyone with a green bone in their body should love rechargeable batteries, but it’s awfully difficult. Alkaline batteries provide always available power, last a long time, and are widely available and inexpensive, while rechargeables are expensive, unpredictable, and usually dead when you need them. As a fan of green technology, I was frustrated at the prospect of buying throwaway alkaline batteries, but could not find a better solution until now. The La Crosse BC-700 battery charger has reversed my impression of rechargeable batteries. It’s that good.
It’s The Chargers That Suck, Not The Batteries
Rechargeable battery technology has advanced dramatically in my lifetime. When I was a kid, nickel cadmium batteries (NiCd) were the only game in town when it came to portable rechargeables. Now, nickel metal hydride (NiMH) and lithium-ion or polymer batteries have taken over in most applications. Surprisingly, the basic chemistry of these batteries is not entirely responsible for the advantages seen over NiCd.
The main difficulty with rechargeable batteries, whether NiCd, NiMH, or lithium-ion is proper charging, storage, and environmental factors during use. NiMH batteries do have slightly better energy density than NiCd, and lithium-ion batteries leave both behind, but each must be carefully charged according to its specifications to be effective and to last for years of use.
Most common battery chargers found in discount stores are worthless energy pumps that destroy these valuable batteries and ruin their reputation. Proper charging of NiCd and NiMH batteries requires careful monitoring of voltage, current, and temperature, yet simple chargers sold by famous names fail to do any of this. They simply pour a constant supply of power into the battery for a set amount of time, guaranteeing improper charging and reducing the useful life of the cells.
Intelligent Chargers Change Everything
Intelligent battery chargers, like the La Crosse BC-700 I bought, are entirely different. Most monitor the change in voltage during the charging process, allowing NiCd in NiMH batteries to be charged fully and correctly. They also monitor temperature and include intelligent cut off systems to prevent overcharging, thus preserving and protecting rechargeables cells.
The BC-700 is a simple and inexpensive charger that can handle from 1 to 4 AA or AAA batteries. Whereas cheap chargers group batteries in pairs, smart chargers treat each independently of the others. Each battery is monitored for voltage, time, current, and temperature and a display on the front of the unit shows progress and state of charge. The La Crosse BC-9009 is a more-advanced charger that packs more charging power and comes with many batteries and a carrying case.
The La Crosse even has an intelligence refresh mode that continually charges and discharges the battery until it reaches an optimal state of charge. I was able to use this mode to bring a number of older NiCd batteries back to life, saving them from the trash. For example, each of the solar walkway lights in front of my house is powered by a single NiCd AA battery. After two years of service, these lights only lasted a couple of minutes after dark. After a run through the refresh mode on the charger, however, these batteries last hours again. I was even able to revive the NiCd batteries that came with my 10-year-old Creative Nomad Jukebox mp3 player!
It’s really a pity that major manufacturers like Duracell and Energizer package their rechargeable batteries with chargers that will render them useless after just a few months. These vendors seem hopelessly stuck with the disposable alkaline mindset, no doubt trying to protect their current market position. Sadly, these terrible products have ruined the reputation of rechargeable batteries for the general public.
I would not hesitate to recommend purchasing NiCd or NiMH battery cells as long as an appropriate charger is used. Intelligent battery chargers like the La Crosse BC-700 or BC-9009 and Powerex WizardOne are inexpensive and effective, and should be part of the technology arsenal of any green minded geek.
I was looking for advice on when you should use the various modes. Is there a general optimum mode that you can use all the time so as to avoid confusion? And, at what amperage do you do the charging?