Battery. Dual. Pros and cons. I have both.

[Orpedcrow]

(Just an example)(not suggesting optima batteries)
In the case of a diesel were both batteries are used for starting you could run 2 red tops because they are rated more for cranking amps or 2 yellow tops that are rated somewhere in the middle of cranking and deep cycle.

In the other case (where batteries are electrically separated when “off”) you could use a red top for primary and blue top as secondary.

It’s really hard on NON deep cycle batteries to be drained “dead” especially as they get older and the case fills up with scale and sulfates.

 

[Schurkey]

I have dual batteries on my '97 K2500 plow truck.

Clearly, I need to trace the schematics to figure-out how they're supposed to work. The wiring looks like a mess--an extra solenoid, a small fuse block hanging by the wires. Of course, the cable ends were green 'n' fuzzy at both batteries. I replaced 'em with brass terminals crimped to cut-back cables. A year later, those brass terminals are going green 'n' fuzzy.

If I wasn't running the electric motor that powers the hydraulic pump for the plow, that second battery would be G-O-N-E. Nothing but headache and heartache as far as I'm concerned. However, if the vehicle genuinely has some additional electric load, the second battery can be justified.

For my truck, the extra load is the plow. For diesels, it's the glow-plugs and ginormous starter motor pushing against ultra-high compression. And of course campers, salt-spreaders, Tommy Lifts, and such as has already been described.

 

[RichLo]

I've been staying out of this one because its been about factory options which I dont have any experience with. but if you need dual batts for whatever your reason I would highly recommend a manual switch inside the cab to switch from left to both to right or both off.

I have this in my plow truck, see the pic below, its the large switch inside the cubby hole compartment on top of the heater controls. Run both ground cables through the firewall to go to the switch and another cable back to the engine/frame/body grounds. The ground is for safety in case it rubs through the cable insulation and it also allows you to still run auxiliary wires off your positive battery posts if you need to.

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[Orpedcrow]

A year later, those brass terminals are going green 'n' fuzzy.

Ugh, the green death isnt fun.
Those greasy, felt, donuts the high school kid at oriellys try’s to sell you work though by keeping the acid that’s leaking out between the lead terminal and the cheap plastic case from corroding your terminals.

 

[Rocket Surgeon]

I appreciate the excellent replies. More info to continue would be awesome.

I agree that 98 wiring diagrams don't seem consistent with the 98 truck setup.

I am concerned that the 98 with the battery delete appears to have the solenoid left active, with two wires cut... first thing I did was cut the ends clean and wrap them to be safe. I need to check the wires with a voltmeter.

Whatever I do with either, I would prefer it to be easily reversible

or...

maybe even a modification where the solenoid is switched on only when needed? No battery, no problem. Need battery, stick it is and close a switch to make it active.

I'm not working these vehicle hard at this moment.

 

[Orpedcrow]

I want to see pictures of the current setup

 

[GoToGuy]

I've been staying out of this one because its been about factory options which I dont have any experience with. but if you need dual batts for whatever your reason I would highly recommend a manual switch inside the cab to switch from left to both to right or both off.

I have this in my plow truck, see the pic below, its the large switch inside the cubby hole compartment on top of the heater controls. Run both ground cables through the firewall to go to the switch and another cable back to the engine/frame/body grounds. The ground is for safety in case it rubs through the cable insulation and it also allows you to still run auxiliary wires off your positive battery posts if you need to.

You must be registered for see images attach

Rather than run high amperage wiring through firewall into pass compartment, did you consider some constant duty relays, with switch controls on dash panel, keeping your load wiring shorter distance between points?

 

[GoToGuy]

Ugh, the green death isnt fun.
Those greasy, felt, donuts the high school kid at oriellys try’s to sell you work though by keeping the acid that’s leaking out between the lead terminal and the cheap plastic case from corroding your terminals.

They will work, I grew up using the "NOCO" brand, also the brush on red goo.
It's most commonly the " Hydrogen Sulfide " vapor from the charge discharge cycle that is vented from the battery vents that condensates on anything nearby. And being an Acid gas it does the acid thing.
A good remedy that lasts is coating the battery attachments is some " Dielectric grease" also known as silicon grease . Dielectric is insulating, does not conduct electricity. Brush some on those connections at the battery area or any other exposed connection to prevent the "cancer corrosion" as preventative medicine. Good luck.

 

[RichLo]

Rather than run high amperage wiring through firewall into pass compartment, did you consider some constant duty relays, with switch controls on dash panel, keeping your load wiring shorter distance between points?

I did and that is by far the better setup for running a manual switch in the cab for both batteries. But being a plow truck on a budget I could get the marine/RV dual battery switch for around $20 and I had access to free 0-gauge industrial wire so after buying the right terminals to crimp onto that wire I was only in it for $30-$40 total. And thats with upgrading to full 0-gauge "big-3" grounds. Big-4 including directly grounding my plow pump too.

And I figure, if people run batteries from the trunk up to the front all the time, I probably dont have any more cable length than that.

 

[Erik the Awful]

if you need dual batts for whatever your reason I would highly recommend a manual switch inside the cab to switch from left to both to right or both off.

Rather than run high amperage wiring through firewall into pass compartment, did you consider some constant duty relays, with switch controls on dash panel, keeping your load wiring shorter distance between points?

I think if you don't have a need for dual batteries, they're not worth the complexity. That said, I'd go the above route with constant duty relays. Keep it simple.