Yes, I think what you have to take a look at is lithium-ion cost versus lead-acid cost. And just in rough numbers, you're looking at anywhere between $6 to $1,000 per kilowatt-hour for a lithium-ion because of the battery management system that has to be put on at the casing and everything else, versus the lead-acid battery, where you're looking at about $150 per kilowatt-hour. Even -- and then we've done studies on this. If you take the cost of our lithium-ion battery, and you cut in half, you cut it in half, we still believe that the competitive -- the customers will go with the lead-acid application for a couple of reasons. First off, if you're into a data center or you're into a telecommunications or standby battery, you don't cycle the battery. In other words, what's happening, is the only time that battery is ever used is when the electricity goes out. So is by cycling the battery, what I mean by that is, you charge it, you discharge it, you charge it, you discharge it, on a battery what's called on float, you hardly ever discharge it. So you really don't get the advantage of cycle-ability that lithium-ion offer. And its customers aren't willing to pay for it. So when you look at our base business, to make it easy, I don't see a major threat with lithium-ion on a reserve power, I don't see it on our motive power. At least I don't see it on motive power because weight is good. Lead-acid batteries are heavy, and you want that counterbalance. But where I do see it as a threat is in our OptiGrid. And the reason I say that is because if you're going to buy electricity or store electricity when it's cheap, at night time, at the low areas, let's say you're buying it for $0.25 a kilowatt-hour, and then when it jumps up during the peak period to $1 a kilowatt-hour, you're dumping it back, what that means is you're going to cycle these batteries a lot. 365 days in a year, if you cycle it every day, on the lead-acid battery, you got 4 to 5 years. On a lithium-ion battery, you probably got 10 to 15 years. So lithium-ion is one that could possibly impact our OptiGrid. Now that being said, that being said, we are working on a lithium-ion solution.