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WK2 - New battery type and location

84K views 176 replies 73 participants last post by  billt 
#1 ·
THE 2011 GRAND CHEROKEE USES ABSORBENT GLASS MAT (AGM) BATTERY TECHNOLOGY

An AGM battery is a sealed unit that uses special relief valves to vent vapors from the battery. The electrolyte is stored in sponge like separators consisting of matted glass filters. This suspension increases the efficiency of the charging and discharging rate of the battery. Continuous under and overcharging is detrimental to this type of battery, therefore; voltage and current regulation are critical.

Typical battery chargers ARE NOT SUITABLE as the voltage and current regulation ranges of typical battery chargers are unsafe for AGM batteries.

THE BATTERY FOR THE JEEP GRAND CHEROKEE IS LOCATED UNDER THE FRONT PASSENGER SEAT AND REMOTE JUMP-START POSTS ARE LOCATED UNDER THE HOOD TO ASSIST IN JUMP STARTING

--WK2Jeeps.com
 
#4 ·
High vibration and impact resistance
Higher charge efficiency allows recharging with less energy
Hermetically sealed , virtually no gassing under normal operating conditions
Can dispense charge at a higher rate

Absorbed Glass Mat (AGM) batteries are the latest step in the evolution of lead-acid batteries. Instead of using a gel, an AGM uses a fiberglass like separator to hold the electrolyte in place. The physical bond between the separator fibers, the lead plates, and the container make AGMs spill-proof and the most vibration and impact resistant lead-acid batteries available today. Even better, AGMs use almost the same voltage set-points as flooded cells and thus can be used as drop-in replacements for flooded cells.
 
#11 ·
Exactly, it's 2010... companies should be making things easier for us. Last time I had a battery issue I was stuck alone and had to have AAA come bail me out. They pulled my old one out, threw the new one in and I was on my way. Now I'd have to be towed to a dealer it sounds like.
Yeah, I don't like the sounds of this. Why on earth would they make it so difficult to change and at a cost of nearly $500 for the battery alone? :eek:
 
#12 ·
Well it'll make it easier to run cables for stereo systems.
 
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#16 ·
http://www.windsun.com/Batteries/Battery_FAQ.htm

AGM, or Absorbed Glass Mat Batteries

A newer type of sealed battery uses "Absorbed Glass Mats", or AGM between the plates. This is a very fine fiber Boron-Silicate glass mat. These type of batteries have all the advantages of gelled, but can take much more abuse. We sell the Concorde (and Lifeline, made by Concorde) AGM batteries. These are also called "starved electrolyte", as the mat is about 95% saturated rather than fully soaked. That also means that they will not leak acid even if broken.

AGM batteries have several advantages over both gelled and flooded, at about the same cost as gelled:

Since all the electrolyte (acid) is contained in the glass mats, they cannot spill, even if broken. This also means that since they are non-hazardous, the shipping costs are lower. In addition, since there is no liquid to freeze and expand, they are practically immune from freezing damage.

Nearly all AGM batteries are "recombinant" - what that means is that the Oxygen and Hydrogen recombine INSIDE the battery. These use gas phase transfer of oxygen to the negative plates to recombine them back into water while charging and prevent the loss of water through electrolysis. The recombining is typically 99+% efficient, so almost no water is lost.

The charging voltages are the same as for any standard battery - no need for any special adjustments or problems with incompatible chargers or charge controls. And, since the internal resistance is extremely low, there is almost no heating of the battery even under heavy charge and discharge currents. The Concorde (and most AGM) batteries have no charge or discharge current limits.

AGM's have a very low self-discharge - from 1% to 3% per month is usual. This means that they can sit in storage for much longer periods without charging than standard batteries. The Concorde batteries can be almost fully recharged (95% or better) even after 30 days of being totally discharged.

AGM's do not have any liquid to spill, and even under severe overcharge conditions hydrogen emission is far below the 4% max specified for aircraft and enclosed spaces. The plates in AGM's are tightly packed and rigidly mounted, and will withstand shock and vibration better than any standard battery.

Even with all the advantages listed above, there is still a place for the standard flooded deep cycle battery. AGM's will cost 2 to 3 times as much as flooded batteries of the same capacity. In many installations, where the batteries are set in an area where you don't have to worry about fumes or leakage, a standard or industrial deep cycle is a better economic choice. AGM batteries main advantages are no maintenance, completely sealed against fumes, Hydrogen, or leakage, non-spilling even if they are broken, and can survive most freezes. Not everyone needs these features.
 
#19 ·
Found this on that same website:

Lifespan of Batteries

The lifespan of a deep cycle battery will vary considerably with how it is used, how it is maintained and charged, temperature, and other factors. In extreme cases, it can vary to extremes - we have seen L-16's killed in less than a year by severe overcharging, and we have a large set of surplus telephone batteries that sees only occasional (5-10 times per year) heavy service that are now over 25 years old. We have seen gelled cells destroyed in one day when overcharged with a large automotive charger. We have seen golf cart batteries destroyed without ever being used in less than a year because they were left sitting in a hot garage without being charged. Even the so-called "dry charged" (where you add acid when you need them) have a shelf life of 18 months at most. They are not totally dry - they are actually filled with acid, the plates formed and charged, then the acid is dumped out.
These are some typical (minimum - maximum) typical expectations for batteries if used in deep cycle service. There are so many variables, such as depth of discharge, maintenance, temperature, how often and how deep cycled, etc. that it is almost impossible to give a fixed number.
  • Starting: 3-12 months
  • Marine: 1-6 years
  • Golf cart: 2-7 years
  • AGM deep cycle: 4-7 years
  • Gelled deep cycle: 2-5 years
  • Deep cycle (L-16 type etc): 4-8 years
  • Rolls-Surrette premium deep cycle: 7-15 years
  • Industrial deep cycle (Crown and Rolls 4KS series): 10-20+ years
  • Telephone (float): 2-20 years. These are usually special purpose "float service", but often appear on the surplus market as "deep cycle". They can vary considerably, depending on age, usage, care, and type.
  • NiFe (alkaline): 5-35 years
  • NiCad: 1-20 years
 
#21 ·
The battery sounds great & I understand that it is leaps & bounds better.
I'm just curious why move it from under the hood & why move it under the seat.
Maybe they needed to get more room under the hood & under the seat was wasted space?
 
#25 ·
Terminals under the bonnet for jump starting could be used for charging.

had a AGM for starting for 6 years now in my WG/WJ.
And an Optima AGM for a second fridge battery for 5 years.

Optima are very popular with the audio guys. And seem to be a great battery.

I would think moving the battery under the seat would help protect it from the extreme cold and heat.
And lower the centre of gravity.
 
#28 ·
Ditto. The "Plus" models I have are all AGM rated. I've got a motorcycle battery going on it's 8th year of service thanks to always keeping it on a Battery Tender when not in use. When I travel for a week or two (flying) I'll throw the WK2 on a Battery Tender Plus to ensure a long service life.
 
#29 ·
I have an Exide roll-around unit with 2/40 amp charging and 200 amps for jumps. It's been used successfully on all manner of trucks, SUVs, cars and tractors, but never with AGM batteries.

From what's been implied in this thread, is it harmful to use a charger like this, or to jump start a vehicle, with an AGM battery?
 
#30 · (Edited)
This is a good read: http://batterytender.com/resources/frequently-asked-questions

I cannot answer as to if your Exide charger is acceptable for AGM batteries. However, never use a battery charger that does not specifically state it can be used with AGM batteries. AGM batteries require a different charging method (controlled by an "intelligent" charger) than the standard lead acid car batteries. An improper charger can ruin the cells of an AGM battery; improper charging is also a common cause of early failure for standard lead acid batteries, not just the AGM type.

edit: Forgot to add that yes it is safe to jump start an AGM battery-equipped vehicle (safer than the wet cell lead acid types).
 
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#33 ·
^^ Ditto, my volve battery was in the trunk, and it was a 02 and I sold it in 2010 with the original battery. Went through an alternator but not a battery.. Loved it in the trunk for optimum SUB wiring.. haha
 
#34 ·
New member, and hello to all, but I have three questions about my 2011 GC Overland:

1.) Will giving or receiving a "jump" cause a problem with the new battery type?

2.) What kind of charger do I have to buy to replace my current lead acid battery charger?

3.) How do you remove the plastic cover from the "hot" jumper cable connection point?

I had my wife bring the new Jeep to work one night because my 1994 jeep battery was dead, and was really surprised when I popped the hood. Fortunately, got a jump that night from a friend.

I have found the information manuals that come with the jeep to be no more useful than their marketing literature. This searching for any useful information started with trying to figure out the programming for the computer/entertainment/GPS and has now expanded into the mechanicals. But that's a discussion for another thread.

Appreciate any info you can give.
 
#36 ·
Jumping procedure is nearly identical to the traditional battery method using the under hood positive and negative posts. The positive plastic cap just flips open. While there are AGM style chargers, you can still use your existing charger, but as said above, older style chargers may not shut off once the battery is fully juiced so a newer charger may be useful.

+1 to the AGM battery advantages and the new location away from engine bay heat. Generally, these are the best batteries available and are expensive to produce. They don't leak even if broken, give off no fumes, do not heat during recharging, and have very slow discharge rates when sitting dormant (2-3%/monthly). My guess is we'll be replacing these AGM's quite a bit less than a traditional cell. YMMV.
 
#35 ·
See the JG thread on getting the right and proper printed manuals -- three are available for the WK2. (Unfortunately, the full service manual isn't available.) But from what I've read and been told, jumping it is no problem. I've read pros and cons about different types of trickle chargers for AGM batteries, but at this juncture I plan to continue using my veteran rollaround Exide charger at the 40A setting to perk up a flagging battery.

For trickle charging if you leave your GC garaged unused for weeks on end, you might want to consider a floating type. A site for this www.batterytender.com isn't coming up tonight, but was working a couple of weeks back.

What seems odd is placing the battery under the seat. On the V6, at any rate, there's gobs of room in front of the engine to put in several batteries.
 
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