I figure I should live up to the words of my manifesto and introduction and share a truly Packworthy item. Eventually, I’ll develop a scale or find some nifty WordPress plug-in that will facilitate rating them. In the meantime, I’ll say that the item in question ranks way up there on the chart.
Sanyo Eneloop batteries are not brand new, they have been out for a few years now. Since I have switched over to them two years ago, I won’t ever return to standard Nickel-Metal Hydride (NiMH) cells. For the uninitiated, Eneloops are an evolution of NiMH cell chemistry. 1.2v NiMHs replaced 1.2v NiCads about a decade ago, its chemistry is imminently less toxic, longer lasting, and does not suffer from a “memory effect.” Battery geeks (of which there are many) will point out that there are some performance issues that do affect NiMH, most can be alleviated with a good charger like the Maha/Powerex MH-C9000 or La Crosse BC-900 (which I own and regularly use). On hindrance that cannot be fixed with an improved charger, is the battery’s tendency to dissipate its own charge. The stored energy in NiMH cells drops quite dramatically over time; a few weeks of storage can render a cell useless as its output voltage may not meet the high requirements of juice-sucking electronics like flashes. There are only two options here and that is to either charge batteries right before you use them, or limit and cycle them so to make sure that no battery sits idle for too long.
I used to have four matched and marked sets of four NiMH AA batteries that I used strictly in two Speedlite flashes. For shoots, I would have two sets loaded and two spares. After the shoot, I would take the spares and load them into the flash and charge up the other sets to use as spares on the following day’s shoot. Where this system falls apart is when the span of time between shoots grows from hours to days or weeks. That is when you have to re-recharge (or as I half-assedly put it “pre-charge”) batteries in preparation for a shoot. This assumes that you have the luxury of scheduling and loads of preparation time to babysit your battery charger.
Thankfully Sanyo re-engineered the NiMH battery when creating the Eneloops, producing a cell that can hold its charge much longer. Self-discharging is a property of most all battery chemistries and it is impossible to completely eliminate. But the Eneloops sure do try.
Appeasing the battery geeks, the Eneloops are rated at 2000 mAh and in practice via my own non-scientific testing; I initially found that figure less attractive than the 2700 or 2900 mAh cells found at my local electronics retailer. Sanyo’s 2000 mAh rates a bit under 2000 mAh in test measurements, whereas the crappy Super Mario Power 2000 cells advertised at 2700 mAh barely break 2000 mAh in the real world.
Eneloops don’t need a special charger, any standard NiMH one will do and they work quite well in high draw applications like powering flashes. They really shine in long-term low-draw applications like powering TV remotes. My electric toothbrush using 2xAAA NiMH cells needs a charge about every 3-4 weeks, whereas an Alkaline set would last 6-8 months. Switching to Eneloops has matched the long term performance that disposable Alkaline cells show.
Eneloops are also more environmentally friendly as they don’t need to be pre-charged and therefore require less charging over the lifespan of the battery. Of course, by using any rechargeable battery eliminates the waste produced by single-use alkaline batteries and their wasteful plastic and paperboard packaging.
Essentially, the Packworthiness of Eneloop batteries comes from their readiness. When you take them out of storage, they click their boots together and salute like a West Point Army cadet. On long excursions or extended holidays where AC power may be a luxury rather than a functional staple of daily life, a portable DC power source that is reliable is an imperative. The cost of Eneloops are comparable, if not slightly more expensive than other performance-oriented (not the generic cheapos) NiMH cells. Their overall advantage is certainly worth the middling added expense.