99% of our customers use standard flooded lead-acid batteries, like what is found in most cars and trucks. Most batteries in the US, regardless of the name on the label, are produced by one of just a handful of manufacturers, including Johnson Controls, East Penn and Exide. Thanks to how these are marketed, you usually won’t find any hint of the manufacturer’s name on what you buy at the store, so it can be nearly impossible for the average person to tell what they’re actually buying.
We have seen an incredibly high sudden failure rate from just one of these manufacturers: Exide. In their defense, it was at a time when they were having financial trouble. Still, even now that they’re doing better, we tend to prefer brands that have a better reliability history. As such, we generally recommend that any battery that is identified as an Exide be immediately replaced with one from another manufacturer, even if the Exide was brand new. We’ve had customers scoff at this recommendation, only to call us out on an urgent basis a few months later because their Exide battery suddenly died for no reason. YMMV
We have no beef against Exide other than our own experience with sudden failures with their batteries. We’re posting this simply because we don’t want people to think that we go on site and pick on whatever battery we see the generator has installed in an effort to sell them another battery. Also, we hope it will make it less difficult for a customer to believe that a brand new battery, fully charged and straight from the store won’t work, as this is another situation we’ve found ourselves in repeatedly.
Since so many batteries are rebranded so as to make identification almost impossible, you may need to do some research to confirm. Johnson Controls currently makes batteries for Sears DieHard, Wal-Mart and several others. They usually have an elongated octagon for vent caps. East Penn is usually sold as Deka. But things can change quickly so don’t be afraid to ask.
Of course, if you’re wanting something a bit more special (and a lot more expensive) like capacitors or lithium, we have worked with those as well – just ask.