geordi wrote:
I get mine from Costco - As large as will fit the space with as many CCA as possible. Any Group 34 will do for the physical space. Costco is currently selling Interstate brand, and the warranty is amazing. No questions asked, full refund. Since lead acid batteries can be 100% recycled an infinite number of times, there really is no reason to ever keep one past the warranty anyway.
I never had any issues with the charging system overcharging it anyway, I always measured 13.6-14 volts from the engine and the battery likes that just fine. The charging system should be checking the voltage anyway and stopping the power when it detects it is full. The main reason they used an AGM battery was that it was spillproof if you managed to get your "trail rated" brand new $30,000 SUV upside down on a trail somewhere, or the supposed "diesel vibrations" that would be bad for the battery. Neither condition is really plausible. Run a standard wet cell and drive on. There are plenty of other things to re-engineer and overthink, batteries don't need to be on the list.
How does that compare in size to a group 78 battery?
I use the same group 78 dual post batteries I run in my 6.5 diesels. 800 to 850 CCA - The most cranking amps I can get at the time I need to purchase them and always dual post.
Group L" W"
34 - 78 10.30 6.80
35 9.10 6.90
36R 10.40 7.30
40R 10.90 6.90
Looks like group 34 and group 78 batteries are the same size. Are the posts on opposite sides of the batteries?