I don't have a Volt, but rather a 2012 Toyota Camry Hybrid, which I got new. Currently has somewhere around 135-140k miles on it. I don't have hard numbers, but the batteries seem to still be in decent shape. The biggest work I've had done is replacing the brakes. Everything has been standard maintenance.

While I'd definitely encourage looking at a hybrid, it may be worth the while to wait a few more years and see how full-blown electric cars hold up. That's my plan at least.