I have an electric toothbrush with a rechargeable battery; it uses a clever little inductive charger as a base, and worked very well until recently. It wouldn’t retain any charge for a few subsequent uses, so I figured that the nickel-cadmium battery in it had bitten the dust.* As it happens, the design is quite decidedly sealed, and the manufacturer definitely does not endorse battery replacement. Frustrated at the prospect of throwing away a perfectly good chassis and motor (and of paying $30 for a new one, when all I needed was a $5 battery), I decided the only sensible thing to do was to hack it, Instructables-style. I figured I could even replace the NiCd with a high quality nickel-metal hydride one, and my toothbrush would be even better than a new one.

The instructions say “Caution! Opening the handle will destroy the appliance and invalidate the warranty,” and they are probably right. I am not a patient person, and so I managed to mangle it quite nicely while disassembling it (though with the aid of a Dremel, I did learn how I might be able to take one apart properly in the future). Adding to my frustration though, the battery they used wasn’t anywhere as exotic as the pair of 2/3A’s that I thought I was going to need to solder together. It was a single lowly, ubiquitous AA.
Now realistically, there are a lot of reasons for a company to design a toothbrush that’s sealed. It requires fewer parts, which means less (expensive) tooling when manufacturing. It also improves the reliability because you can gasket a sealed unit very thoroughly. Ultimately, the cost savings mean you can deliver a high-quality product at a reasonable price. While the company could readily produce a design with a replaceable battery and sell it for a few dollars more, it’s not really in their economic interest, because the $30 replacement cost is low enough that most consumers won’t think twice about buying a new one. Planned obsolescence is a cash cow for manufacturers, but frustrating as hell from a sustainability point of view, and there’s no easy way to reconcile the two angles. As it is, the other components are definitely robust beyond the life-span of a single battery, and because there’s no way to recycle the co-moulded plastic/rubber case, you end up with a tremendous amount of waste for a high-end product that is designed to be disposable.
This is the kind of challenge that faces any product designer with a conscience, and right now, there is little incentive for manufacturers to change their ways. Designing products for disassembly and recycling would increase costs, and the vast majority of consumers would likely throw it out, anyway. For product design to truly become sustainable, we either need a material revolution or we need to radically change our model of consumption. One way to do this is to make manufacturers responsible for end-of-life disposal of products. While this sounds like a ridiculous proposition to North Americans, the idea has been embraced by the European Union, which has begun introducing measures to make manufacturers accountable for their waste. If phased in properly, such initiatives can allow smart manufacturers with a cradle-to-cradle mentality to save money. One such success story is Interface, a carpet company which has vowed to eliminate any negative environmental impact from its products by 2020; as it has implemented new techniques for recycling its products at the end of their lifespan, they have actually managed to reduce their costs. It goes to show that, yet again, sustainable development often makes equally as much sense from a financial point of view as an environmental one.
*In the end, it turns out that the outlet that the charger had been plugged into in the bathroom had tripped its switch, and stopped working. Once I reset it, it worked again, so I’m pretty sure that the battery in my old toothbrush was decidedly alive and well for at least another few months, and this whole exercise was for naught. So it goes.