For what it's worth, I've been using the Sears DieHard Platinum 34/78DT for a few years now. Sounds like you're not going this route, but it may prove useful to those interested:
As mentioned previously, it is widely believed (with good reason) that the Sears Platinum batteries are manufactured by EnerSys Energy Products, Inc., which happens to be the same company that manufactures the Odyssey batteries.
Click here for Sears press release stating as much.
The equivalent (read:identical) Odyssey battery to the Platinum 34/78DT would be the
Odyssey PC1500DT. Identical specs, different casing color. Info I pulled from a random GIS:
I called EnerSys Inc. headquarters in Colomubia, Maryland, and was referred to their Warrensburg, Missouri, plant, and specifcally to plant Engineer Scott Lichte (660-429-7556). Scott confirmed the following:
- That particular plant is the only place in the world that make the Odyessy battery, and it is also the only place where the Diehard Platinum is manufactured.
- The Odyessy PC1500 DT is the exact same battery as the Diehard 34/78DT, the only difference at all is the color of the plastic.
- Sears has a larger customer base than Odyessy so they buy stock in much greater quantity which drives the resale cost down for the customer as compared to Odyessy.
- There is no difference in connecting to the top terminals of this battery versus the side terminals, all operation is identical between the two sets.
- A draw of 700 amps at 9V would last about 1.5 minutes with this battery (engine off of course).
(link)
Take it with a grain of salt -- it's just word of mouth (unless you want to try calling that plant engineer for yourself). Though, there seems to be some validity to it, as the specs appear identical between the two batteries. If they are made by the exact same company, and the specs are the same, what are the odds that they are made at the exact same plant? Why pay extra for Odyssey if you have no facts to indicate that the two batteries are any different? If the specs and warranty are identical, why not save yourself some money? Okay, I'll stop berating you with rhetorical questions.
I don't recall the Platinum 34/78DT requiring any drastic modification to get it bolted into the factory 2007 battery tray location, but perhaps my memory fails me. I may have used a spare battery hold-down bracket I had laying around, or perhaps it came with one -- I don't remember. If you're at all mechanically inclined, I'm sure you can figure something out.
The reviews on Sears seem to indicate a possible structural integrity issue with the battery's side-terminals, but it seems those were regarding batteries purchased circa 2007-2009 -- it's possible that EnerSys redesigned them since then. Regardless, I'd stick with the top terminals if you go this route -- I used the top terminals without incident. The only negative reviews for the battery are from those who used the side-terminals with subsequent mechanical failure. The single 4-star rating was from someone who gave the battery a 5-star rave review, but "didn't want Sears to get too smug and stop working on the battery" and gave it a 4-star for that reason. That makes sense. not.
(Sears 34/78DT Link)
I'm not running a dual battery setup (as I don't have any power-hungry accessories to necessitate it), but I think this would be a very decent choice for a primary "starting" battery in a dual battery application.
It's cheaper to replace if something goes wrong, and it's got 880 cold-cranking amps (@ 0?F), which is +265 CCA more than my previous battery. That translates to about 1100CA @ 32?F, or 1275 HCA @ 80?F. I personally tend to value cold cranking amps (CCA) above reserve capacity (RC) for a starting purposes, as I'm mostly concerned about getting my truck started in winter weather (-when the car's electrical demands are greater + I hate being cold). And if a battery can supply that for 30-seconds, it can definitely do it for 5. Starter motors generally require greater
power (high energy over a short period of time), upwards of 500 amps over a few seconds of cranking, rather than prolonged use at a comparatively-miniscule 25 amps used for testing reserve capacity. If you live in a warmer southern climate year-round, RC is more important, but the 34/78DT has awesome RC ratings as well.
Assuming the Odyssey PC1500DT and the DieHard Platinum 34/78DT are the same battery, the fast discharge rates are as follows:
1,500 amps for 5 seconds <-- PHCA
1,280 amps for 10 seconds
1,170 amps for 15 seconds
1,100 amps for 20 seconds
It's worked well for me thus far -- engine always starts right up with no hesitation, even after the truck sat for a few weeks in the winter. I'll likely buy it again in the event that this one fails. Of course, your mileage may vary, but I don't think you'll find a better "starting" battery at a similar price-point.