The concept of rechargeable zinc batteries have been around since Thomas Edison. It's too bad the batteries themselves haven't worked very well. Start-up PowerGenix, however, says the picture is changing and to prove its point, the company announced that its nickel zinc rechargeables have passed two crucial milestones. Underwriters Laboratory said that the company's batteries have passed safety and reliability tests. During the examination, the batteries were subjected to shock, vibration, crush, projectile, impact and discharge tests under extreme temperatures. Oh, and short circuiting tests. The company's batteries have also been certified for recycling by the Rechargeable Battery Recycling Corp., a nonprofit that organizes recycling standards for batteries. So what's it all mean? That PowerGenix's nickel-zinc batteries can be sold in largely the same channels as other rechargeable batteries, such as lithium-ion and nickel metal hydride batteries. PowerGenix says its batteries can provide 30 percent more power than regular nickel batteries while weighing less. And they won't burst into flames like lithium ion batteries (or Super Bowl halftime performers.) The company is designing batteries for both the portable market (i.e cell phones and power tools) and plug-in hybrids. Plus, zinc is a just a fun element all the way around. It's been a long, hard road. PowerGenix has touted its batteries for years, but only started shipping commercially this Spring. Another company, ZPower (formerly Zinc Matrix Power) has similarly had to work tinker with its chemistry for years.

The dam is breaking for water companies. Miox, an Albuquerque-based company that makes systems that disinfect water with salt, has recently raised another round of funding, according to sources. The company raised $14.5 million in January 2007 from, among others, Sierra Ventures. The name has popped up a lot lately. The funding comes on the heels of an $11.5 million dollar round in July for Halosource. Halosource produces a system in which chlorine and bromine are used to disinfect water. The trick is that the chemicals are captured in beads so drinkers don't get a chemical-y aftertaste. Earlier this month, of course, desalination company Energy Recovery held its IPO. The stock went out at $8 and is trading in the $11 range. And just yesterday I was speaking to Claude Laval, who told me about a water and energy incubator at Fresno State. In Miox's system, electricity converts salt into sodium hypochlorite and/or mixed oxidants, which then get injected into water. Salt electrolysis has been around for decades--bleach giant Clorox started this way. Miox, however, claims that its onsite equipment is more electrically efficient than conventional products and has been optimized to squeeze the benefits of putting mixed oxidants in water. Using solids to disinfect has numerous advantages over standard pressurized chlorine gas or bleach. Delivering chlorine as salt cuts down on transportation and handling costs as well as improves plant safety, according to the company. Tests also show that it prevents fouling of membranes and pipes, which in turn reduces maintenance costs. Standard chlorine can also result in unwanted or dangerous chemical byproducts that have to be eliminated by further processes. Several VCs have told me the love the concept of investing in water. There's only a finite amount on the earth and demand is escalating. The tough part is finding good deals. The customer base can also be tricky. Municipal water districts are some of the big customers of this kind of equipment and they move at a glacial pace. Still, agribusiness buys a lot of water equipment.