Two battery questions

Q1: Is there any reason to not run a deep cycle in the front and standard in the rear?

I have an optima blue top laying around rated at 750 CCA (I think). My other battery is a "commercial" 31 or 35 series lead acid battery from a farm supply chain. rated at 800 or 850 CCA.

Q2: I don't have room for the rear battery tray with the 6.5 turbo setup. Is there a concensus oppinion on where/how to relocate?

options seem to be:
a) buy two new batteries that fit on one tray. [strike]What size are these? I've seen the pics on here but don't know what size/series they are.[/strike] edit: seems that it's 31s and optima 34s that do this.

b) cut/chop rear tray to move it closer to the ouside of the vehicle. Might work if the battery is short enough to not get shorted on the hood.

c) fabricate something to move 2nd battery to front drivers side. This seems like the best option space wise but will require lots of extra high-current wire for the starter or relocating the 24V terminals (or just wire starter directly to + terminal and then run some 12 or 10 ga wire to the 24V terminal for the noise supressor and V-meter?). This seems like it would require the most complicated fabrication too.


Anything I'm not thinking of? Tendancy for the weight to stress drivers side inner fender or something?

Anyway, looking for wisdom of experience here. Thanks!

You might find some useful info in my thread on the subject.

I just did mine last week Here's what I came up with,......

I am running civilian battery trays on the driver and passenger side. They fit well and are more compact than the military versions. I used standard 6ft battery cables from oreilly's to run across the front of the radiator. Really the only thing you need to do is ground the driver side to the frame and run a single positive over to the other battery but I wasn't thinking when I installed my cables and ran both to the passenger battery.



Edit: I know I need to work on the connections on the top of the passenger battery. Someone else did that disaster and I haven't fixed it yet.

So the drivers side is the +12v above chasis? Did you have to change out the large chasis ground cable from the engine (seperate from the braided grounding strap near the back). Mine had something like that but it was a radio truck at one time and had some extra +24V cables running to the rear seat.

Mine is 12v so its pretty straight forward. but if it was 24 I would wire the driver side like the front battery.

@MarcusOReallyus

I saw that one eventually. I LOLed at the title (don't know if you intended to allude to that famous shock video or not)

All you have to do is extend the battery cables to the driver side.

I PUT 2 Optima blue tops on the rear battery tray and removed the front battery tray for my used vegetable oil filter, heater, water separator... and my siren.

You should run a matching pair of standard starting batts. Deep cycles have no reason in a standard Cuck. Unless you are doing some serious winching or running them down all the time, starting batts only. Even if you are, a hybrid like a yellow top (which I despise) would be a good compromise.

Skinny said:

You should run a matching pair of standard starting batts. Deep cycles have no reason in a standard Cuck. Unless you are doing some serious winching or running them down all the time, starting batts only. Even if you are, a hybrid like a yellow top (which I despise) would be a good compromise.

Click to expand...

Is it just because you typically get lower cranking amps for a given weight with deep cycles?

I was going to pick up another blue-top to match the one I have on the shelf. Same cost as buying two new smaller regular batteries and I thought it would make me cool

Deep cycles are designed to be brought from fully charged to discharged (actually 50% if you want them to last) where a starting battery is designed for short high amperage draws. Has to do with the number and thickness of the lead plates. Both will work and interchange but a starting battery will quickly die if you discharge it on a regular basis and deep cycles do not like short intermittent high amperage pulls. That is why most trucks work best with a quality starting or hybrid battery. Deep cycles belong in RV's, boats, and golf carts. Spending more doesn't get you more.

Dual purpose marine batteries work just fine as long as you don't have very cold weather. Group 27 batteries are the same size as 31s except for the terminal locations, not a real problem if you carefully arrange the hold downs.

i would not use them for a 12 volt conversion since the 24 volt system uses half the current for cranking as a 12 volt.