Run mobile office from car - Install a very large battery - Safe?

[bluechipwi]

My job requires me to run 2-6 amp/hr 12 volt power demands.
With my previous car (1998 Jetta III - 2.0L) I replaced stock battery with a large 1000 cold crank truck size battery. I could go untethered for 5 to10 hours before I recharge via 110v - 6 amp trickle charger.
The previous setup worked fine per over sized battery rating to car's electrical system.
Should I have any CONCERNS if I replace stock battery with same size truck battery (in trunk / battery case) for my 2000 Honda civic?.

 

[Trekk]

12 volts is 12 volts the bigger the battery the larger the supply life. In other words you could have a battery the size of a building that is only 12 volts. Bigger batteries just have bigger plates in the cells but the same amount of cells. You can also run 2+ batteries it just comes down to how you wire them up. If you if we're to wire them pos to pos, neg to neg you just make a bigger 12v battery (bigger cells) If you wired them pos to neg (series) you would go up 12v per battery (12v 24v 36v ect) then you would fry the car (more cells)

A car battery has 6 cells each at 2.1v wired in a series 2.1, 4.2, 6.3, 8.4, 10.5, 12.6v.

 

[bluechipwi]

12 volts is 12 volts the bigger the battery the larger the supply life. In other words you could have a battery the size of a building that is only 12 volts. Bigger batteries just have bigger plates in the cells but the same amount of cells. You can also run 2+ batteries it just comes down to how you wire them up. If you if we're to wire them pos to pos, neg to neg you just make a bigger 12v battery (bigger cells) If you wired them pos to neg (series) you would go up 12v per battery (12v 24v 36v ect) then you would fry the car (more cells)

A car battery has 6 cells each at 2.1v wired in a series 2.1, 4.2, 6.3, 8.4, 10.5, 12.6v.

Thanks for your comments - You and I agree on the math.
My new approach will have both stock car battery and new large battery as 2x separate power sources.
The large battery will have it's own 110v charging / monitor system. I will term 12 volt car adapter wiring from car electrical circuit and source directly from large battery (trunk) for mobile office power needs.
A possible option to parallel large trunk battery to small car battery with a blade disconnect switch ... could use as an instant jump for starting car (closed), then return blade to open position.

 

[Drunken Yak inc]

I would ensure that your second battery has proper ventilation and protection if mounted in your trunk, like mounting an RV/Pontoon boat external battery box.

 

[bluechipwi]

I would ensure that your second battery has proper ventilation and protection if mounted in your trunk, like mounting an RV/Pontoon boat external battery box.

Thanks for the comment.
Like minds agree - Last August purchased the Attwood 9084-1 Large Battery Box at Amazon. Box is OK, but disappointed when no "Hold Down" strap came with it. Picture view on seller / Amazon site AND the Mfg site always displayed the box with the strap.. The (1) review is mine.
I do have concerns about possible vapors in the trunk causing rust ... should I be concerned?

 

[Trekk]

Does that box have a vent tube?

 

[Drunken Yak inc]

I would agree that you were correct in assuming it came with a strap. It shows the strap and doesn't say that it's not included. The box says it's vented, hopefully via tube that you could run through the floor pan. My concern with the fumes is because of their toxicity to you, and with you spending significant time in your car, there is a high potential for an excessive level of exposure.

 

[bluechipwi]

No tube provided .. I'll drill a hole for best position in box on a test install and nipple it out to acid resistant hose through floor pan of trunk.
Thanks guys ... you all have been helpful.