Why has no one tried to securely mount a 2nd battery in the cargo area of our JK's. Is the large guage copper wire that expensive to run from the engine compartment to the + and - terminals of a battery in back of our JKs? Chevrolet is advertising this is a setup of a specialty vehicle in 2012. Are there any harmful effects of a liquid free battery being charged in the passenger compartment. I don't know if those types of batteries release harmful gas as sometimes warning lables indicate on my motorcycle battery.

Im looking at purchasing the electronics to keep the 2nd battery charged with the alternator, and switchable as the Benchmark kit electronics has. If it was done right and mounted securely it should not be a hazard right? Plenty of room back there in the wagon.

I was thinking about doing this myself with an optima style battery that could be mounted any which way, along with a couple of auxillary power points, maybe even an 1000w inverter back there. You could still jump start your own jeep or throw a switch to the 2nd battery to start or run if you wanted to.

I'm not crazy about the current options placing that 2nd battery over the sparkplugs and the exhaust manifold is why.
Any thoughts would be appreciated.

 

way back before someone made a kit for under the hood a couple people did that. I remember reading the posts

 

the OP talks about benchmark which is the company that sells the kit you're talking about, so I'm sure he's aware of that kit, but for some reason he wants the battery inside the jeep

 

A sealed battery should be safe for use in the passenger compartment. I shudder to think how much that 0 gauge wire is going to run you though....

FWIW, many of us (myself included) have been running the dual setup in the engine bay without issue. Especially if you still have stock exhaust headers with their heat shields installed, you should be fine. I understand your concern though, so good luck with whatever you do.

Let us know how much you pay for the wire

 

40ft of 2 gauge wire ran me $80 Canadian a while back, and that was with getting jumper cables and destroying them (it was literally 2x cheaper than just buying the cable from a spool). Yeah, definitely not cost effective... 0 gauge... good luck.

 

In the past there's been concern about leakage and gases escaping into the bay. Also, what if your battery shorts or decides to explode.


The batteries INSIDE most cabs now are all Litium Ion based and designed for that application. Even an Optima gel cell wasn't intended for that purpose. Not to mention the ammount 0 gauge wire you'd need to run. Scrape that cable on a rock then do a water crossing and goodbye electrical system.

It's an interesting, but non safe idea.

 

I don't believe this is correct. Absorbed Glass Mat (AGM) batteries, such as the Odyssey and Optima lines, have the electrolyte fully absorbed in a material such that even if the sealed case is ruptured, they will not spill or leak. Also, this type of battery is recombinant, which means that any gas released during charging is re-absorbed by the water and electrolyte, so there is nothing at all released from the cell. Sealed means sealed.

Odyssey's own web site states that they are safe to mount in the passenger compartment:

odysseybatteries.com/applications/auto.htm


There is a moderate safety concern in running very high amperage wiring over distances that long, but lots of people do it. When you're pricing out the wire, be sure to add some 3-400 Amp fuses -- I would not want a run that long in my vehicle that was not adequately protected. As Skippman mentioned, if you allow the battery to short, there is no telling what type of damage might ensue -- anything from melting or arcing to explosions would not be out of the question

 

I agree with mmccurdy... as long as you stick to AGM or Gel Cell batteries, you will be fine. I have seen hundreds if not thousands of inverter installations inside the cabins of recreational boats and none have blown up or killed anyone... keep in mind ALL of these installations used either AGM or Gel Cell batteries.

AGM batteries are superior to standard gel cells. People tend to call everything a gel cell that isn't your standard car battery, and of course this is incorrect. Here is some good info from batterystuff.com...

" Wet Cell (flooded), Gel Cell, and Absorbed Glass Mat (AGM) are various versions of the lead acid battery. The Wet cell comes in two styles; Serviceable and Maintenance free. Both are filled with electrolyte and are basicly the same. I prefer one that I can add water to and check the specific gravity of the electrolyte with a hydrometer. The Gel Cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell. However they store very well and do not tend to sulfate or degrade as easily as wet cell. There is little chance of a hydrogen gas explosion or corrosion when using these batteries; these are the safest lead acid batteries you can use. Gel Cell and some AGM batteries may require a special charging rate. If you want the best,most versatile type, consideration should be given to the AGM battery for applications such as Marine, RV, Solar, Audio, Power Sports and Stand-By Power just to name a few. If you don't use or operate your equipment daily, AGM batteries will hold their charge better that other types. If you must depend on top-notch battery performance, spend the extra money. Gel Cell batteries still are being sold but AGM batteries are replacing them in most applications. There is a some common confusion regarding AGM batteries because different manufactures call them by different names; some of the more common names are "sealed regulated valve", "dry cell", "non spillable", and "Valve Regulated Lead Acid" batteries. In most cases AGM batteries will give greater life span and greater cycle life than a wet cell battery.
SPECIAL NOTE about Gel Batteries: It is very common for individuals to use the term GEL CELL when referring to sealed, maintenance free batteries, much like one would use Kleenex when referring to facial tissue or "Xerox machine" when referring to a copy machine. Be very careful when specifying a battery charger, many times we are told by customer they are requiring a charger for a Gel Cell battery and in fact the battery is not a Gel Cell.

AGM: The Absorbed Glass Matt construction allows the electrolyte to be suspended in close proximity with the plates active material. In theory, this enhances both the discharge and recharge efficiency. Common manufacturer applications include high performance engine starting, power sports, deep cycle, solar and storage battery. The larger AGM batteries we sell are typically good deep cycle batteries and they deliver their best life performance if recharged before allowed to drop below the 50% discharge rate. The Scorpion powersports batteries we carry are a nice upgrade from your stock flooded battery, and the Odyssey branded batteries are fantastic for holding their static charge over long periods of non use. When Deep Cycle AGM batteries are discharged to a rate of no less than 60% the cycle life will be 300 plus cycles.

GEL: The Gel Cell is similar to the AGM style because the electrolyte is suspended, but different because technically the AGM battery is still considered to be a wet cell. The electrolyte in a Gel Cell has a silica additive that causes it to set up or stiffen. The recharge voltage on this type of cell is lower than the other styles of lead acid battery. This is probably the most sensitive cell in terms of adverse reactions to over-voltage charging. Gel Batteries are best used in VERY DEEP cycle application and may last a bit longer in hot weather applications. If the incorrect battery charger is used on a Gel Cell battery poor performance and premature failure is certain. "

The most important thing to note from that info is that a battery that is called "sealed" or "maintenance free" do NOT necessarily mean AGM or gel cell.

Ben

 

A lot of good information here and I, myself, have learned quite a bit. I know traditional lead/acid and other style batteries are not safe for use in a vehicle. I had no idea the Optima was that well designed.

I didn't mean to give the impression you'd be driving around with something akin to a pipe bomb in your trunk and I'm sorry if that's the way my post came across. I just know that in the risk/reward analysis of what you're trying to do a dual battery tray under the hood is far safer.

 

Blues2, did you end up mounting the battery in the cargo area? I need to do the same as the CRD doesn't have room under the bonnet like the v6.

Can you post some pics of the setup. I already have the cable running to an andersen plug on the tow bar for the battery in the caravan but also want to have the battery in the vehicle for day trips.