I have had pretty good luck with the Battery Tender Jr's and even the knock offs, I run the BTJ's on my stuff and bought a bunch of the knockoffs cause we used them down the shop for stuff that isn't run often. Even with the big trucks they do the job, just yesterday the driver said one of them sh*t the bed. But I am going to hook it to a battery we have sitting around to see if it really did. But they take some beating from the driver and keep on ticking for the most part