Ooops, I haven't been on here in a few weeks and missed this post. I did replace with NAPA. I had battery trouble in Newfoundland this summer and Napa ended up replacing both the batteries for free once I got home. I'm not sure of the exact cause of the failure but I'm pretty sure it was exacerbated by the batteries being wired parallel. I ended up rewiring the batteries with a switch so that I can run on either, both, or disconnect both. I'd definitely recommend that change. Having two batteries seems pointless to me unless you can use one or the other in the case of a single failure and both when necessary. I've got a thread on here somewhere about the failure and rewiring.
Ooops, I haven't been on here in a few weeks and missed this post. I did replace with NAPA. I had battery trouble in Newfoundland this summer and Napa ended up replacing both the batteries for free once I got home. I'm not sure of the exact cause of the failure but I'm pretty sure it was exacerbated by the batteries being wired parallel. I ended up rewiring the batteries with a switch so that I can run on either, both, or disconnect both. I'd definitely recommend that change. Having two batteries seems pointless to me unless you can use one or the other in the case of a single failure and both when necessary. I've got a thread on here somewhere about the failure and rewiring.
I think you'll find blue top and yellow top are the same battery, the only difference is the terminals.
reviving this thread from the dead, I am curious how those that have gone with a single battery are finding the cranking and starting of the engines with one of the oem batteries? I have recently re and re'ed my battery set up and went to one battery for starts and it seems OK, just that when cold out it has a bit of a slow initial turn over but easy start, The batteries are fully charged and hold a charge well but they are maintenance free batteries so I cant use an hydrometer to determine the state of it, The other battery is sitting in the garage and I am planning to use it as a spare when the one in the truck dies. Any one in cold country using one battery??
I experimented with using one and both batteries a month or so ago when it was close to zero degrees. With one battery there was a momentary hesitation when first turning the key to start but then it kicked in just fine. I like having the option of one or both.